Collision Worksheet Multiple Choice - Excel by wbd21056

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									Multiple Failure Modes Lock Evaluation Tool




Purpose: This software supports multi-objective tradeoff analysis for the evaluation of design alternatives for lock
walls that are vulnerable to extreme events, specifically barge impacts and earthquake loads. A major result of
the approach is the identification of a combination of (i) scenarios of extreme events, and (ii) design alternatives
that are most useful for a subsequent probabilistic cost-benefit analysis.

Software developers: Joshua L. Tsang, James H. Lambert*, Center for Risk Management of Engineering
Systems, University of Virginia, Charlottesville, VA (* address for correspondence); Robert C. Patev, U.S. Army
Corps of Engineers

Version 1b. Updated on May 14, 2001.
alternatives for lock
 A major result of
design alternatives


Engineering
 Patev, U.S. Army
Contents

This workbook contains the following worksheets:

Design Parameters - Barge Impact
        In this worksheet a user enters three design alternatives to evaluate. Relationships between impact level and repair cost
        and between impact level and time to recover are assessed from the user.
Design Parameters - Earthquake
         In this worksheet a user enters three design alternatives to evaluate. The alternatives can be the same or different from
         the alternatives entered in the 'User Input - Barge Impact' worksheet. Relationships between ground motion and repair
         cost and between ground motion and time to recover are assessed from the user.
Cost-Closure Matrix
         In this worksheet the user enters (1) costs of closures to industry and (2) reconstruction cost.
Event Scenarios - Barge Impact
         In this worksheet, the user enters three barge impact scenarios under which to test the alternatives.
Event Scenarios - Earthquake
         In this worksheet, the user enters three earthquake scenarios under which to test the alternatives.
Tradeoffs - Barge Impact
         This worksheet displays the tradeoffs between the alternatives in terms of cost of alternative and a consequence under
         the barge impact scenarios. The possible consequences include repair cost / reconstruction cost, repair cost, time to
         recover, and cost to industry.
Tradeoffs - Earthquake
         This worksheet displays the tradeoffs between the alternatives in terms of cost of alternative and a consequence under
         the earthquake scenarios. The possible consequences include repair cost / reconstruction cost, repair cost, time to
         recover, and cost to industry.
Tradeoffs - Integrated
         This worksheet displays the tradeoffs between the alternatives in terms of cost of alternative and a consequence under
         the barge impact and earthquake scenarios. The possible consequences include repair cost / reconstruction cost, repair
         cost, time to recover, and cost to industry.
ct level and repair cost



same or different from
nd motion and repair




 consequence under
repair cost, time to



 consequence under
epair cost, time to



 consequence under
onstruction cost, repair
Getting Started
There are three main ways to use this tool, and they are indicated by the following arrows:
(1) perform both barge impact and earthquake analyses
(2) perform only barge impact analysis
(3) perform only earthquake analysis

   Wall Type




  Design                  Design
  Parameters -            Parameters -
  Barge Impacts           Earthquakes




                        Cost-Closure Matrix




                         Event Scenarios -          Event
                         Barge Impact               Scenarios-
                                                    Earthquakes




                                                     Tradeoffs -          Tradeoffs -         Tradeoffs
                                                     Barge Impact         Earthquakes         Integrated




Note: The labels in the rectangles refer to the names of the worksheets

Essential steps have a red asterisk (*) by their numbers.
arrows:




          Tradeoffs -
          Integrated
Wall Type
                                                                              Yellow Filled Cells Indicate User Input Area




*Step 1. What wall is being considered?                       (e.g., Upper Middle Wall, Upper River Wall, Lower Middle
                                                              Wall, Lower Land Wall)
To consider another wall, open another copy of the workbook and save it under a different name.


Design Parameter - Barge Impact
*Step 2. Enter design loads and costs of alternatives for barge impact analysis in the order of increasing costs (cost of
alternative 1 less than or equal to cost of alternative 2 less than or equal to cost of alternative 3).

The design load of an alternative is typically in the regime of extreme events, which are rare and severe in consequence.

The three alternatives can be a baseline, a design that is a little more costly and one that is signficantly more costly. The
alternatives can also be a baseline, one that is less costly, and one that is more costly than the baseline.




                                                                               Alternatives
                                                              1                      2                                                     3

                  Name of Alternative
                                        Design Load (kips)




                                                                                Design Load (kips)




                                                                                                                      Design Load (kips)
                                                                  Cost ($k)




                                                                                                     Cost ($k)




                                                                                                                                               Cost ($k)




*Step 3. Answer the following questions to characterize the relationship between damage and impact force.

Note: Minimum and maximum values are optional.
For each alternative, what is the greatest barge impact force (kips) that results in no damage cost ?


                                                             Alternative 1:                                      Alternative 2:                                         Alternative 3:
                                                                    0                                                     0                                                   0
                                                                                *Most Likely




                                                                                                                                               *Most Likely




                                                                                                                                                                                         *Most Likely
                                                                  Maximum




                                                                                                                      Maximum




                                                                                                                                                                             Maximum
                                        Minimum




                                                                                                     Minimum




                                                                                                                                                              Minimum




                                                                                                                                                                                                        kips

For each alternative, what is the repair cost ($k) for a barge impact equal to the design load ?


                                                             Alternative 1:                                      Alternative 2:                                         Alternative 3:
                                                                   0                                                     0                                                    0
                                                                                *Most Likely




                                                                                                                                               *Most Likely




                                                                                                                                                                                         *Most Likely
                                                                  Maximum




                                                                                                                      Maximum




                                                                                                                                                                             Maximum
                                        Minimum




                                                                                                     Minimum




                                                                                                                                                              Minimum




                                                                                                                                                                                                        $k
                                         For each alternative, what is the least barge impact force (kips) that results in total reconstruction cost ?


                                                                                                                   Alternative 1:                                                                Alternative 2:                               Alternative 3:
                                                                                                                                                0                                                      0                                                                   0




                                                                                                                                                                 *Most Likely




                                                                                                                                                                                                                     *Most Likely




                                                                                                                                                                                                                                                                                                 *Most Likely
                                                                                                                                               Maximum




                                                                                                                                                                                                      Maximum




                                                                                                                                                                                                                                                               Maximum
                                                                                            Minimum




                                                                                                                                                                                       Minimum




                                                                                                                                                                                                                                    Minimum
                                                                                                                                                                                                                                                                                                                  kips


                                         Note: An assumption governing the ratio of reconstruction cost to construction cost is found on the Cost-Closure Matrix
                                         worksheet.


                                                     Alternative 1                                                                                                               Alternative 2                                                                                                                          Alternative 3

                                                                                                                                                1                                                                                                                                           1
                                         1




                                                                                                                                                                                                                                                   (Repair Cost) / (Reconstruction Cost)
                                                                                                                                              0.9
                                                                                                      (Repair Cost) / (Reconstruction Cost)
(Repair Cost) / (Reconstruction Cost)




                                                                                                                                              0.8                                                                                                                                          0.8
                                        0.8
                                                                                                                                              0.7
                                                                                                                                              0.6                                                                                                                                          0.6
                                        0.6
                                                                                                                                              0.5
                                                                                                                                              0.4                                                                                                                                          0.4
                                        0.4
                                                                                                                                              0.3
                                                                                                                                                                                                                                                                                           0.2
                                        0.2                                                                                                   0.2
                                                                                                                                              0.1
                                                                                                                                                                                                                                                                                            0
                                         0                                                                                                      0
                                                                                                                                                                                                                                                                                                 0                0.2      0.4      0.6   0.8       1   1.2
                                              0             0.5          1            1.5                                                                0                            0.5                       1                       1.5
                                                                                                                                                                                                                                                                                                                    (Impact Lord) / (Design Load)
                                                    (Impact Lord) / (Design Load)                                                                                               (Impact Lord) / (Design Load)
                                                                                                                                                                                                                                                                                                                Most Likely Value          Left bound

                                                                                                                                                             Most Likely Value                                  Left bound                                                                                      Right bound
                                              Most Likely Value          Left bound
                                                                                                                                                             Right bound
                                              Right bound




                                         Step 4. Enter available historical data on up to four barge accidents involving lock walls.

                                                                                                                                              Design Load                            Cost of Wall                   Barge Impact                 Cost of Repair
                                                   Date              Description of Accident
                                                                                                                                                 (kips)                                  ($k)                        Load (kips)                      ($k)




                                         Step 5. Compare the damage functions with the historical data in Figure 1. If they are very different, go
                                         back to step 3 and modify the answers until the user feels comfortable that the assessed relationship is
                                         consistent with the historical data.



                                         Reminder:

                                         Alternative 1:                                0
                                         Alternative 2:                                0
                                         Alternative 3:                                0
                                            (Repair Cost) / (Reconstruction Cost)
                                                                                      1
                                                                                    0.9
                                                                                    0.8                                                                                                        Alternative 1
                                                                                    0.7                                                                                                        Alternative 2
                                                                                    0.6
                                                                                    0.5                                                                                                        Alternative 3
                                                                                    0.4                                                                                                        Historica Data
                                                                                    0.3
                                                                                    0.2
                                                                                    0.1
                                                                                      0
                                                                                          0             1            2                                    3
                                                                                              (Impact Load) / (Design Load)




                            Figure 1. Damage Functions for Barge Impact Analysis
                            Note: A straight line interpolation is performed among the points assessed in Step 3.




                            *Step 6. Answer the following questions to characterize the relationship between time to recover and impact force .


                            Note: Minimum and maximum values are optional.
                            For each alternative, what is the greatest barge impact force (kips) that results in no closure of the lock?




                                                                                                                                    Alternative 1:                                            Alternative 2:                                  Alternative 3:
                                                                                                                                          0                                                         0                                               0
                                                                                                                                                              *Most Likely




                                                                                                                                                                                                                     *Most Likely




                                                                                                                                                                                                                                                                                    *Most Likely
                                                                                                                                               Maximum




                                                                                                                                                                                                    Maximum




                                                                                                                                                                                                                                                   Maximum
                                                                                                                  Minimum




                                                                                                                                                                                    Minimum




                                                                                                                                                                                                                                    Minimum




                                                                                                                                                                                                                                                                                                    kips


                            For each alternative, what is the duration of closure (weeks) that results from a barge impact equal to the design load ?




                                                                                                                                    Alternative 1:                                            Alternative 2:                                  Alternative 3:
                                                                                                                                          0                                                         0                                               0
                                                                                                                                                              *Most Likely




                                                                                                                                                                                                                     *Most Likely




                                                                                                                                                                                                                                                                                    *Most Likely
                                                                                                                                               Maximum




                                                                                                                                                                                                    Maximum




                                                                                                                                                                                                                                                   Maximum
                                                                                                                  Minimum




                                                                                                                                                                                    Minimum




                                                                                                                                                                                                                                    Minimum




                                                                                                                                                                                                                                                                                                    weeks


                            For each alternative, what is the least barge impact force (kips) that results in a lock closure for one year or more?




                                                                                                                                    Alternative 1:                                            Alternative 2:                                  Alternative 3:
                                                                                                                                          0                                                         0                                               0
                                                                                                                                                              *Most Likely




                                                                                                                                                                                                                     *Most Likely




                                                                                                                                                                                                                                                                                    *Most Likely
                                                                                                                                               Maximum




                                                                                                                                                                                                    Maximum




                                                                                                                                                                                                                                                   Maximum
                                                                                                                  Minimum




                                                                                                                                                                                    Minimum




                                                                                                                                                                                                                                    Minimum




                                                                                                                                                                                                                                                                                                    kips




                                        Alternative 1                                                                                                                        Alternative 2                                                                                                                   Alternative 3

                  >52
                   50                                                                                                                    >52
                                                                                                                                          50                                                                                                                                   50
                                                                                                                                                                                                                                                                               >52
                                                                                                                       Time to Recover
Time to Recover




                                                                                                                                                                                                                                                             Time to Recover




                  40                                                                                                                     40                                                                                                                                    40

                  30                                                                                                                     30                                                                                                                                    30
                  20                                                                                                                     20                                                                                                                                    20
                  10                                                                                                                     10
                                                                                                                                                                                                                                                                               10
                   0                                                                                                                      0
                                                                                                                                                                                                                                                                                0
                        0                  0.5                                                 1            1.5                                0                              0.5                              1                     1.5
                                                                                                                                                                                                                                                                                       0                         0.5           1          1.5
                                  (Impact Load) / (Design Load)                                                                                               (Impact Load) / (Design Load)
                                                                                                                                                                                                                                                                                                        (Impact Load) / (Design Load)

                             Most Likely Value                                                 Left Bound                                                Most Likely Value                                    Left Bound                                                                           Most Likely Value         Left Bound
                             Right Bound                                                                                                                 Right Bound                                                                                                                               Right Bound
Right Bound   Right Bound   Right Bound
Step 7. Enter available historical data on up to four barge accidents involving lock walls.

                                                                                                      Time to
                                                                     Design Load   Barge Impact
                            Date      Description of Barge Impact                                     Recover
                                                                        (kips)      Load (kips)
                                                                                                      (weeks)




Step 8. Compare the time-to-recover relationship with the historical data in Figure 2. If they are very
different, go back to step 6 and and modify the answers until the user feels comfortable that the
assessed relationship is consistent with the historical data.



Reminder:

Alternative 1:                                         0
Alternative 2:                                         0
Alternative 3:                                         0

                            60

                            50
  Time to Recover (weeks)




                            40                                                      Alternative 1
                                                                                    Alternative 2
                            30
                                                                                    Alternative 3

                            20                                                      Historical Data


                            10

                             0
                                 0        0.5              1              1.5
                                     (Impact Load) / (Design Load)


Figure 2. Time-to-Recover Relationship for Barge Impact Analysis
Note: A straight line interpolation is performed among the points assessed in Step 6.

Step 9. Click on the 'Design Parameters - Earthquake' worksheet if analysis of risks of earthquakes to alternatives is also
desired. Otherwise, click on the 'Cost-Closure Matrix' worksheet.
Design Parameter - Earthquake
                                                                           Yellow Filled Cells Indicate User Input Area



*Step 10. Enter design ground motion (G.M.) and the costs for the alternatives for earthquake analysis in the order of
increasing costs (cost of alternative 1 less than or equal to cost of alternative 2 less than or equal to cost of alternative 3).
Design ground motions are typically in the neighborhood of the maximum credible earthquake (MCE) and/or the maximum design
earthquake (MDE).
                                                                            Alternatives
                                                           1                      2                                               3
                          Name of
                          Alternative

                                        Design G.M. (g)




                                                                             Design G.M. (g)




                                                                                                                Design G.M. (g)
                                                               Cost ($k)




                                                                                               Cost ($k)




                                                                                                                                      Cost ($k)
*Step 11. Answer the following questions to characterize the relationship between damage and ground motion.


Note: Minimum and maximum values are optional.
For each alternative, what is the greatest ground motion that results in no damage cost?


                                                          Alternative 1                                    Alternative 2                                       Alternative 3
                                                                 0                                                 0                                                 0
                                                                             *Most Likely




                                                                                                                                      *Most Likely




                                                                                                                                                                               *Most Likely
                                                               Maximum




                                                                                                                Maximum




                                                                                                                                                                    Maximum
                                        Minimum




                                                                                               Minimum




                                                                                                                                                     Minimum




                                                                                                                                                                                              g

For each alternative, what is the repair cost for a ground motion equal to the design ground motion?



                                                          Alternative 1                                    Alternative 2                                       Alternative 3
                                                                 0                                                 0                                                 0
                                                                             *Most Likely




                                                                                                                                      *Most Likely




                                                                                                                                                                               *Most Likely
                                                               Maximum




                                                                                                                Maximum




                                                                                                                                                                    Maximum
                                        Minimum




                                                                                               Minimum




                                                                                                                                                     Minimum




                                                                                                                                                                                              $k

For each alternative, what is the lowest ground motion that results in total reconstruction cost?



                                                          Alternative 1                                    Alternative 2                                       Alternative 3
                                                                 0                                                 0                                                 0
                                                                             *Most Likely




                                                                                                                                      *Most Likely




                                                                                                                                                                               *Most Likely
                                                               Maximum




                                                                                                                Maximum




                                                                                                                                                                    Maximum
                                        Minimum




                                                                                               Minimum




                                                                                                                                                     Minimum




                                                                                                                                                                                              g




          Alternative 1                                                                                                                                                                            Alternative 3
                                                                                 Alternative 1                                                                          Alternative 2                                                                           Alternative 3

                         1                                                                                                                       1                                                                                       1




                                                                                                                                                                                                                (Reconstruction Cost)
(Reconstruction Cost)




                                                                                                                        (Reconstruction Cost)
                        0.8                                                                                                                     0.8                                                                                     0.8




                                                                                                                                                                                                                   (Repair Cost) /
   (Repair Cost) /




                                                                                                                           (Repair Cost) /
                        0.6                                                                                                                     0.6                                                                                     0.6

                        0.4                                                                                                                     0.4                                                                                     0.4

                        0.2                                                                                                                     0.2                                                                                     0.2

                         0                                                                                                                       0                                                                                       0
                              0                                                      0.5            1             1.5                                 0                 0.5                1              1.5                                 0                  0.5              1           1.5
                                  (Actual Ground Motion) / (Design Ground Motion)                                                                         (Actual Ground Motion) / (Design Ground Motion)                                         (Actual Ground Motion) / (Design Ground Motion)
                                                                                                                                                          Most Likely Value             Left Bound                                                Most Likely Value             Left Bound
                                  Most Likely Value                                              Left Bound
                                                                                                                                                          Right Bound                                                                             Right Bound
                                  Right Bound




                              Step 12. Enter available historical data on up to four earthquakes that damaged lock walls.

                                                                                                                                                                    Cost of Wall                          Cost of Repair
                                                                           Date             Description of Earthquake Design G.M. (g)                                                   Actual G.M. (g)
                                                                                                                                                                        ($k)                                   ($k)




                              Step 13. Compare the damage function with the historical data in Figure 3. If they are very different, go
                              back to step 11 and modify the answers until the user feels comfortable that the assessed relationship
                              is consistent with the historical data.




                              Reminder:

                              Alternative 1:                                                                  0
                              Alternative 2:                                                                  0
                              Alternative 3:                                                                  0
                                   (Repair Cost) / (Reconstruction Cost)




                                                                           1.2

                                                                            1

                                                                           0.8                                                                                                Alternative 1
                                                                                                                                                                              Alternative 2
                                                                           0.6
                                                                                                                                                                              Alternative 3
                                                                           0.4                                                                                                Historical Data


                                                                           0.2

                                                                            0
                                                                                 0                 0.5                  1                                    1.5
                                                                                       (Ground motion) / (Design Ground Motion)


                              Figure 3. Damage Function for Earthquake Analysis
                              Note: A straight line interpolation is performed among the points assessed in Step 11.
*Step 14. Answer the following questions to characterize the relationship between time to recover and ground motion.


Note: Minimum and maximum values are optional
For each alternative, what is the greatest ground motion that results in no closure of the lock?




                                                Alternative 1                            Alternative 2                            Alternative 3
                                                      0                                        0                                        0




                                                                *Most Likely




                                                                                                         *Most Likely




                                                                                                                                                  *Most Likely
                                                     Maximum




                                                                                              Maximum




                                                                                                                                       Maximum
                                      Minimum




                                                                               Minimum




                                                                                                                        Minimum
                                                                                                                                                                 g


For each alternative, what is the duration of closure that results from a ground motion equal to the design ground motion?




                                                Alternative 1                            Alternative 2                            Alternative 3
                                                      0                                        0                                        0
                                                                *Most Likely




                                                                                                         *Most Likely




                                                                                                                                                  *Most Likely
                                                     Maximum




                                                                                              Maximum




                                                                                                                                       Maximum
                                      Minimum




                                                                               Minimum




                                                                                                                        Minimum
                                                                                                                                                                 weeks


For each alternative, what is the least ground motion that results in a lock closure for one year or more?




                                                Alternative 1                            Alternative 2                            Alternative 3
                                                      0                                        0                                        0
                                                                *Most Likely




                                                                                                         *Most Likely




                                                                                                                                                  *Most Likely
                                                     Maximum




                                                                                              Maximum




                                                                                                                                       Maximum
                                      Minimum




                                                                               Minimum




                                                                                                                        Minimum




                                                                                                                                                                 g




Step 15. Enter available historical data on up to four earthquakes that damaged lock walls.

                                                                                                            Time to
      Date        Description of Earthquake Design G.M. (g) Actual G.M. (g)                                 Recover
                                                                                                            (weeks)
                                                              Alternative 1                                                                      Alternative 2                                                                      Alternative 3

                  50
                  >52                                                                                                      50
                                                                                                                           >52                                                                                50
                                                                                                                                                                                                              >52




                                                                                                         Time to Recover




                                                                                                                                                                                            Time to Recover
Time to Recover




                  40                                                                                                       40                                                                                 40

                  30                                                                                                       30                                                                                 30

                  20                                                                                                       20                                                                                 20

                  10                                                                                                       10                                                                                 10

                   0                                                                                                        0                                                                                  0
                        0                                         0.5         1                1.5                               0                 0.5                   1            1.5                           0                   0.5          1              1.5
                            (Actual Ground Motion) / (Design Ground Motion)                                                          (Actual Ground Motion) / (Design Ground Motion)                                    (Actual Ground Motion) / (Design Ground Motion)



                                      Most Likely Value                           Left Bound                                            Most Likely Value                Left Bound                                       Most Likely Value         Left Bound

                                      Right Bound                                                                                       Right Bound                                                                       Right Bound




                        Step 16. Compare the time-to-recover relationship with the historical data in Figure 4. If they are very
                        different, go back to step 14 and modify the answers until the user feels comfortable that the assessed
                        relationship is consistent with the historical data.

                                                         60

                                                         50
                               Time to Recover (weeks)




                                                         40                                                                                              Alternative 1
                                                                                                                                                         Alternative 2
                                                         30
                                                                                                                                                         Alternative 3

                                                         20                                                                                              Historical Data


                                                         10

                                                          0
                                                              0               0.5                    1                                 1.5
                                                                        (Impact Load) / (Design Load)


                        Figure 4. Time-to-Recover Relationship for Earthquake Analysis
                        Note: A straight line interpolation is performed among the points assessed in Step 14.

                        Step 17. Click on 'Cost-Closure Matrix' worksheet.
Cost-Closure Matrix

                                                                    Yellow Filled Cells Indicate User Input Area


Step 18. Enter the following information to determine the relationship between cost to industry and length of closure. Only
lengths of closure and costs to industry are necessary for calculation in this tool. The information can be obtained from a
waterways analysis model (WAM).




   Description of Event    *Length of Closure
                                                     Tonnage        Transit Time (hours)     Number of Tows        *Cost to Industry ($k)
         (RunID)                (weeks)




Assumption:
               Reconstruction cost is           times more costly than the original construction cost (e.g., 1.3).


Step 19. Click on 'Event Scenarios - Barge Impact' worksheet.
 of closure. Only
obtained from a




3).
Event Scenarios - Barge Impact

                                                                                                                      Yellow Filled Cells Indicate User Input Area

Step 20. The alternatives that were defined in step 2 are evaluated under different barge impact scenarios. Define three scenarios by giving the
magnitudes and return periods. Figure 5 is a graph of the the return periods and magnitudes entered. The usual, unusual, and extreme barge
impact events are recommended as scenarios.

                                                                                                                           Alternative
                                                                                                              1                 2                   3
                                                                                                              0                 0                   0
                                                                       Cost of Alternative ($k)               0                 0                   0
                                                                       Risk Metrics
                                                          Usual Barge Repair Cost / Reconstruction Cost     #DIV/0!          #DIV/0!             #DIV/0!
                                                             Impact    Repair Cost ($k)                     #DIV/0!          #DIV/0!             #DIV/0!
                                      *Magnitude(kips):                Time to Recover (weeks)              #DIV/0!          #DIV/0!             #DIV/0!
                                   Return Period(years):               Cost to Industry ($k)               #VALUE!          #VALUE!             #VALUE!
                                                         Unusual Barge Repair Cost / Reconstruction Cost    #DIV/0!          #DIV/0!             #DIV/0!
            Scenarios




                                                             Impact    Repair Cost ($k)                     #DIV/0!          #DIV/0!             #DIV/0!
                                      *Magnitude(kips):                Time to Recover (weeks)              #DIV/0!          #DIV/0!             #DIV/0!
                                   Return Period(years):               Cost to Industry ($k)               #VALUE!          #VALUE!             #VALUE!
                                                         Extreme Barge Repair Cost / Reconstruction Cost    #DIV/0!          #DIV/0!             #DIV/0!
                                                             Impact    Repair Cost ($k)                     #DIV/0!          #DIV/0!             #DIV/0!
                                      *Magnitude(kips):                Time to Recover (weeks)              #DIV/0!          #DIV/0!             #DIV/0!
                                   Return Period(years):               Cost to Industry ($k)               #VALUE!          #VALUE!             #VALUE!




                           1
  Return Period (years)




                          10
                               0             0.2          0.4         0.6            0.8           1
                                                        Impact Load (kips)

Figure 5. Barge Impact Return Periods.

Step 21. Click on 'Event Scenarios - Earthquake' worksheet if analysis of risks of earthquakes to alternatives are also desired.
Event Scenarios - Earthquake

                                                                                                                                 Yellow Filled Cells Indicate User Input Area



Step 22. The alternatives that were defined in step 9 are evaluated under different earthquake scenarios. Define three scenarios by giving the
magnitudes and return periods. Figure 6 is a graph of the return periods and ground motions entered. The operating basis earthquake and
maximum credible earthquake are potential choices as scenarios.

                                                                                                                                      Alternative
                                                                                                                         1                 2                   3
                                                                                                                         0                 0                   0
                                                                                  Cost of Alternative ($k)               0                 0                   0
                                                                                  Risk Metrics
                                                                       Usual      Repair Cost / Reconstruction Cost    #DIV/0!         #DIV/0!              #DIV/0!
                                                                     Earthquake   Repair Cost ($k)                     #DIV/0!         #DIV/0!              #DIV/0!
                                                   *Magnitude(g):                 Time to Recover (weeks)              #DIV/0!         #DIV/0!              #DIV/0!
                                             Return Period(years):                Cost to Industry ($k)               #VALUE!         #VALUE!              #VALUE!
                                                                      Unusual     Repair Cost / Reconstruction Cost    #DIV/0!         #DIV/0!              #DIV/0!
                         Scenarios




                                                                     Earthquake   Repair Cost ($k)                     #DIV/0!         #DIV/0!              #DIV/0!
                                                   *Magnitude(g):                 Time to Recover (weeks)              #DIV/0!         #DIV/0!              #DIV/0!
                                             Return Period(years):                Cost to Industry ($k)               #VALUE!         #VALUE!              #VALUE!
                                                                      Extreme     Repair Cost / Reconstruction Cost    #DIV/0!         #DIV/0!              #DIV/0!
                                                                     Earthquake   Repair Cost ($k)                     #DIV/0!         #DIV/0!              #DIV/0!
                                                   *Magnitude(g):                 Time to Recover (weeks)              #DIV/0!         #DIV/0!              #DIV/0!
                                             Return Period(years):                Cost to Industry ($k)               #VALUE!         #VALUE!              #VALUE!




                                     1
 Return Period (years)




                             10
                                         0            0.2         0.4        0.6              0.8            1
                                                             Actual Ground Motion (g)
Figure 6. Earthquake Return Period.


Step 23. Click on 'Tradeoffs-Barge' worksheet.
Tradeoffs - Introduction
Possible outcomes with tradeoff graphs:

Comparing alternatives in terms of construction cost and one risk metric (namely, repair cost) under only one scenario, there are a
number of possible cases:

Pareto Optimal Alternatives

    Cost of Alternative


                      x
                             x
                                 x

                          Repair Cost
                                  x
Figure 1. Pareto optimal alternatives


Of the alternatives that are shown in the Figure 1, no any one alternative is better objectively than another. Between any two of the
alternatives, there is tradeoff in the two factors being considered. If one alternative is more costly, then it will also have a smaller
potential repair cost. The choice of an alternative depends on expert judgement or institutional preference.


Dominated Alternative
          Cost of Alternative

                             x
                                            x      Alt 2
                                        x       Alt 1

                          Repair Cost
                                  x
Figure 2. Dominance

In Figure 2, alternative 2 that is to the upper right of alternative 1 is dominated because it is worse than alternative 1 in both
construction cost and repair cost. Therefore, alternative 2 is removed from consideration as a potential design choice.

Horizontal Alignment: Alternative With the Same Cost but Different Levels of Performance

Cost of Alternative

                Alt 1       Alt 2

                 x           x


                 Repair Cost

Figure 3. Horizontal alignment

The outcome in Figure 3 is a special case of dominance in which both alternatives have the same cost, but alternative 2 has a
greater repair cost than alternative 1. Therefore alternative 2 is dominated.
        Vertical Alignment: Alternatives with Same Performance (i.e., Repair Cost) but Different Costs

             Cost of Alternative

                                        x          Alt 2


                                        x          Alt 1

                               Repair Cost

        Figure 4. Vertical alignment

        If the graph appears as in Figure 4, it means that there is no use in investing more than a certain amount. Referring to Figure 4,
        there is no reason to choose alternative 2 and invest the higher amount. Vertical alignment is also a special case of dominance. An
        alternative that is directly above another alternative has no advantage in terms of repair cost.

        Pareto Optimal Alternatives with More than Two Criteria
        Now assume that there are more than one risk metric used in evaluating alternatives. Say there are two, namely repair cost and
        time to recover. Consider the following outcome shown in Figure 5.

    Cost of Alternative                               Cost of Alternative

               x                                                 x
                                   x       Alt 2                         x       Alt 2
                           x           Alt 1                                       x     Alt 1


             Repair Cost                                      Time to Recover

        Figure 5. Example of multiple risk metrics


        In terms of repair cost, alternative 2 is dominated by alternative 1. However, in terms of time to recover there is no dominance. In
        this case, alternative 2 cannot be removed from consideration as a viable solution because now there are two risk metrics to
        evaluate by. One cannot say that one alternative is better than another objectively. The choice between the alternatives may
        depend on factors that are not quantified. For example, if the decision maker considers time to recover as greatly more important
        than repair cost, then the shorter time to recover for alternative 2 may make the alternative 2 the desired option.

        There can be a third and fourth risk metric for evaluation: (repair cost) / (reconstruction cost) and cost to industry. In this case of
        four metrics, an alternative is only dominated when it is worse in all four metrics and in its cost than another alternative.


        Pareto Optimal Alternatives under Multiple Scenarios
        Now consider the case of evaluating alternatives under multiple scenarios as in Figure 6.


         Cost of Alternative

                   x                   O
                                                                     x       100 kips
Alt 2                  x                       O
                                                                     O       1.0 g
Alt 1                          x           O
               Repair Cost

        Figure 6. Example with multiple scenarios, showing the construction costs and repair costs of three alternatives under a barge
        impact and an earthquake scenario.
For the 100kips collision scenario, all three alternatives shown are pareto optimal with respect to the scenario. For the 1g
earthquake, alternative 2 is dominated by alternative 1. Assuming that only one risk metric and two scenarios are used, the
alternatives are pareto optimal.

Considerations in Tradeoff Analysis

When choosing among alternatives, there are several considerations. First, it is important to look for any dominated alternatives.
For example, if alternative A lies vertically above alternative B in the tradeoff graphs for all criteria of interest, then alternative A is
dominated. The presence of dominated alternatives may suggest 1) that a different, more-competitive set of alternatives be chosen
because one alternative appears inferior to another on all the criteria or 2) that there should be a more-severe extreme event
scenario for the analysis (this suggestion is especially true when the values of the criteria for the dominated and dominating pair of
alternatives under the chosen scenarios are zero or very small). After checking for dominated alternatives, a lock wall designer can
consider the tradeoffs under the barge impact and earthquake scenarios for the different risk metrics (e.g., repair cost). The
designer can weigh the tradeoffs among the alternatives with respect to the four different risk metrics.
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epair cost). The
Tradeoffs among Alternatives under Barge Impact Scenarios



Step 24. Graphs of cost of alternative versus each risk metric under the barge impact scenarios are shown below. Each graph provides a different perspective,
and the graphs are labeled with the corresponding perspectives: (a) engineering / finance, (b) finance / engineering, (c) operations / industry, and (d) industry.

Reminder:

                                                   Alternative 1          Alternative 2          Alternative 3

Name                                                          0                       0                      0

Cost ($k)                                                     0                       0                      0



                                                   (a) Engineering / finance:

                                          1
            Cost of Alternative ($k)




                                        0.9
                                        0.8
                                        0.7                                                                      Usual Barge Impact kips years
                                        0.6                                                                      r.p.
                                        0.5
                                                                                                                 Unusual Barge Impact kips
                                        0.4                                                                      years r.p.
                                        0.3
                                        0.2                                                                      Extreme Barge Impact kips
                                                                                                                 years r.p.
                                        0.1
                                          0
                                             0.00       0.20       0.40      0.60         0.80    1.00
                                                     (Repair Cost) / (Reconstruction Cost)




                                                   (b) Finance / engineering:


                                         1
                                       0.9
        Cost of Alternative ($k)




                                       0.8
                                       0.7
                                       0.6
                                       0.5
                                       0.4
                                       0.3
                                       0.2
                                       0.1
                                         0
                                              0          0           0          1            1           1
                                                                   Repair Cost ($k)




                                                   (c) Operations / industry:


                                         1
                                       0.9
 Cost of Alternative ($k)




                                       0.8
                                       0.7
                                       0.6
                                       0.5
                                       0.4
                                       0.3
                                       0.2
                                       0.1
                                         0
                                             0.0        0.2        0.4       0.6          0.8      1.0
                                                              Time to Recover (weeks)
                                      (d) Industry:


                              1
                            0.9
 Cost of Alternative ($k)




                            0.8
                            0.7
                            0.6
                            0.5
                            0.4
                            0.3
                            0.2
                            0.1
                              0
                                  0        0          0       1         1   1
                                                Cost to Industry ($k)



Step 25. Click on 'Tradeoffs-Earthquake' worksheet.
      Tradeoffs among Alternatives under Earthquake Scenarios


     Step 26. Graphs of cost of alternative versus each risk metric under the earthquake scenarios are shown below. Each graph provides a different
     perspective, and the graphs are labeled with the corresponding perspectives: (a) engineering / finance, (b) finance / engineering, (c) operations / industry,
     and (d) industry.

     Reminder:

                                                     Alternative 1         Alternative 2              Alternative 3

     Name                                                      0                    0                           0

     Cost ($k)                                                 0                    0                           0




                                                     (a) Engineer / finance:
                                            1
                                           0.9
               Cost of Alternative ($k)




                                           0.8                                                         Usual Earthquake g years r.p.
                                           0.7
                                           0.6                                                         Unusual Earthquake g years
                                           0.5                                                         r.p.
                                           0.4                                                         Extreme Earthquake g years
                                                                                                       r.p.
                                           0.3
                                           0.2
                                           0.1
                                            0
                                             0.00       0.20       0.40   0.60    0.80     1.00
                                                   (Repair Cost) / (Reconstruction Cost)


                                                     (b) Finance / Engineer:

                                          1000
Cost of Alternative ($k)




                                             0
                                                 0        0          0       1       1            1
                                                               Repair Cost ($k)



                                                     (c) Operations / Industry:


                                        1
                                      0.9
  Cost of Alternative ($k)




                                      0.8
                                      0.7
                                      0.6
                                      0.5
                                      0.4
                                      0.3
                                      0.2
                                      0.1
                                        0
                                             0.0        0.2        0.4    0.6      0.8      1.0
                                                          Time to Recover (week)
                               (d) Industry:


                    1
                  0.9
Cost of Alternative ($k)




                  0.8
                  0.7
                  0.6
                  0.5
                  0.4
                  0.3
                  0.2
                  0.1
                    0
                           0      0        0       1          1   1
                                      Cost to Industry ($k)




Step 27. Click on 'Tradeoffs-Integrated' Worksheet.
Tradeoffs among Alternatives under Barge Impact and Earthquake Scenarios


Step 28. Graphs of cost of alternative versus each risk metric under the barge impact and earthquake scenarios are shown below. The graphs are more
straightforward to interpret when the same set of alternatives is entered for barge impact analysis and for earthquake analysis.


Reminder:

                                                             Alternative 1            Alternative 2          Alternative 3

Name                                                                    0                       0                      0

Cost ($k)                                                               0                       0                      0



                                                             (a) Engineering / finance:

                                                                                                               Usual Barge Impact kips
                                                  1                                                            years r.p.
                                                0.9
                     Cost of Alternative ($k)




                                                0.8                                                            Unusual Barge Impact
                                                0.7                                                            kips years r.p.
                                                0.6
                                                                                                               Extreme Barge Impact
                                                0.5
                                                                                                               kips years r.p.
                                                0.4
                                                0.3                                                            Usual Earthquake g years
                                                0.2                                                            r.p.
                                                0.1
                                                  0                                                            Unusual Earthquake g
                                                      0.00                     0.50                   1.00     years r.p.

                                                             (Repair Cost) / (Reconstruction Cost)             Extreme Earthquake g
                                                                                                               years r.p.




                                                             (b) Finance / engineering:

                                            1
                                          0.9
  Cost of Alternative ($k)




                                          0.8
                                          0.7
                                          0.6
                                          0.5
                                          0.4
                                          0.3
                                          0.2
                                          0.1
                                            0
                                                      0           0            0          1           1            1
                                                                             Repair Cost ($k)




                                                             Operations / Industry:

                                                  1
                                                0.9
             Cost of Alternative ($k)




                                                0.8
                                                0.7
                                                0.6
                                                0.5
                                                0.4
                                                0.3
                                                0.2
                                                0.1
                                                  0
                                                      0.0         0.2        0.4        0.6         0.8      1.0
                                                                      Time to Recover (weeks)
                                     Industry:

                             1
                           0.9
Cost of Alternative ($k)




                           0.8
                           0.7
                           0.6
                           0.5
                           0.4
                           0.3
                           0.2
                           0.1
                             0
                                 0       0        0        1         1   1
                                             Cost to Industry ($k)

								
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