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									CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001




                                        TASK 1.5.4
                     Analysis of Index Buildings
                                           Hiroshi Isoda
                           (Building Research Institute, Japan)

                                       Andre Filiatrault
                                             Bryan Folz
                                           David Fischer
                                            (UC-San Diego)
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001




                                          Overview
• Task Objectives

• Analysis Methodology

• Description of Index Buildings

• Model of Index Building No. 1: Small House
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001




                                Task Objectives
• Perform deterministic non-linear (time-history
  and/or push-over) analyses of four index
  buildings under various earthquake ground
  motions.
• Coordinate with and submit work to the
  Subcontractor of Task 4.1: Improving Loss
  Estimation for Woodframe Buildings.
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001




                  Methodology for Analysis

• Non-linear pushover and time history dynamic
  analysis of the four index buildings will be
  performed using the specialized software being
  developed under Task 1.5.1: Development of
  Seismic Analysis Software for Woodframe
  Construction.
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001


                     Data Input:
                     Enter Building Geometry,                         Connector
                     Material Properties and                          Property
                     Connector Properties                             DataBase
                                                                      (Task 1.4.8.1)




             Shear Wall Analysis Loop:
             For Each Shear Wall:
             1) Run CASHEW, using CUREe Woodframe Loading
                Protocol.
             2) Fit Hysteretic Wall Response to SDOF
                Hysteretic Spring Model.




    Assemble Degenerate 3D-Model: (RUAUMOKO Program)
       · Plane Stress Elements for each Diaphragm.
       · Non-linear Springs for each Shear Wall.
       · Rigid Beam Elements at each Shear Wall to Diaphragm
         Connection.
                                                                    Flowchart for
                                                                    Pushover and Time
                 Seismic Analysis:
                     · Pushover
                                                                    History Analysis of
                     · Dynamic Time History
                                                                    Woodframe Buildings
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001




          Description of Index Buildings
 • Four Index Buildings

 • Three Variants of Each Index Building
       – Superior Quality
       – Typical Quality
       – Poor Quality

 • Retrofit Schemes for Each Index Building
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001




          Description of Index Buildings
      1. Small House: 1 story, 2 bedrooms, 1 bath, 1200
            sq. ft. on a level lot; built before 1970. Two
            variations: with and without cripple walls.


      2. Large House: 2 story, 3 bedrooms, 3 baths, 3 car
            garage, L-shaped; slab on grade and spread
            footings; recently constructed.
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001




          Description of Index Buildings
     3. Small Townhouse: two story 1500-1800 sq. ft.
           unit with common wall; on a level lot; recently
           constructed and engineered design.


     4. Apartment Building: 3 story with ten 800 sq.
           ft. units; all wood construction; parking on
           ground floor; constructed prior to 1970 and
           minimal engineering.
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001

  Model of Index Building No.1: Small House
  • Built circa 1950
  • Roof:
     – Composite shingle felt
     – Solid 1x6 straight sheathing boards
  • Floor:
     – Joists 2x6 @ 16 in
     – Solid 1x6 diagonal sheathing
        boards
  • Ceiling:
     – Gypsum board
  • Exterior Walls:
     – 3-coat 7/8 in exterior stucco
     – Gypsum board interior
  • Interior Walls:                                                               30 ft

     – Gypsum board
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001



                    Variants of Small House
         Superior Quality                     Typical Quality                         Poor Quality
           Stem Wall                    Unbraced Cripple Wall with            Unbraced Cripple Wall with
                                          Average-Quality Stucco                  Poor-Quality Stucco
                                            80% of stiffness and                  55% of stiffness and
                                         strength from high-quality            strength from high-quality
                                              laboratory tests                      laboratory tests
     Good Quality Stucco                  Average Quality Stucco                  Poor-Quality Stucco
     100% of stiffness and                  90% of stiffness and                  70% of stiffness and
  strength from high-quality             strength from high-quality            strength from high-quality
       laboratory tests                       laboratory tests                      laboratory tests
  Superior Nailing of interior            Good Nailing of interior              Poor Nailing of interior
      gypsum wallboard                       gypsum wallboard                      gypsum wallboard
     100% of stiffness and                  85% of stiffness and                  75% of stiffness and
  strength from high-quality             strength from high-quality            strength from high-quality
       laboratory tests                       laboratory tests                      laboratory tests
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001


      Modeling Assumptions For Small House
• Roof:
   – Only in-plane stiffness of ceiling
     considered
   – Gt = 8 kips/in (FEMA 273)
• Floor:
   – Gt = 500 kips/in (FEMA 273)
• Exterior, Interior, and Cripple Walls:
     – Wayne Stewart Hysteretic Model
     – Parameters for Stucco and Gypsum                                           Cripple Wall


       Wall Board Based on UC-Irvine Tests
       for City Of Los Angeles (COLA)
     – Parameters for Cripple Walls based on
       UC-Davis Tests for CUREE-Caltech
       Woodframe Project
         CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001

                                                                                        Hysteretic Model & Parameters




                                                  UC-Davis 2-ft Level Cripple Wall Tests                                                           UC-Irvine Gypsum Board Tests
                                                              City of LA - Shear Wall Tests
                                                8'x8' - 7/8" Stucco w / 3/8" Head Furring Nails @ 6"/6"


                                                                            4000

                                                                            3500

                                                                            3000

                                                                            2500

                                                                            2000

                                                                            1500

                                                                            1000
Load (pounds)




                                                                             500

                                                                                0
                -2.00   -1.75   -1.50   -1.25   -1.00   -0.75   -0.50   -0.25    0.00   0.25    0.50   0.75   1.00   1.25   1.50   1.75   2.00
                                                                             -500

                                                                            -1000

                                                                            -1500

                                                                            -2000

                                                                            -2500

                                                                            -3000

                                                                            -3500

                                                                            -4000
                                                                        Displacement (inches)




                    UC-Irvine Stucco Tests                                                                                                       Wayne Stewart Hysteretic Model
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001


                              Analysis Example
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001


                                                      Analysis Results
                                       Construction Variant                                                          Fundamental Frequency                          Mode of Vibr
                                                                                                                            (Hz)
                                             Poor-Quality                                                                   4.35                                           Y-directio
                                            Typical-Quality                                                                 5.13                                           Y-directio
                                            Superior-Quality                                                                10.5                                           Y-directio

                                 Floor Displacements                                                                           Ceiling Displacements
                    3                                                                                       3
                                                           Floor Level (Node 41)                                                                         Ceiling Level (Node 16)
                    2                                                                                       2
Displacement (in)




                                                                                        Displacement (in)
                    1                                                                                       1


                    0                                                                                       0
                         0   5        10              15           20              25                            0         5        10              15              20              25
                    -1                                                                                      -1

                                                                Poor-Quality                                                                                     Poor-Quality
                    -2                                                                                      -2                                                   Typical Quality
                                                                Typical Quality
                                                                Superior-Quality                                                                                 Superior-Quality
                    -3                                                                                      -3
                                           Time (s)                                                                                      Time (s)
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001


                        Hysteresis Loops: Foundation Walls
                    Poor-Quality (Stucco Cripple Wall)                                                                                                        Typical-Quality (Stucco Cripple Wall)
                  15
                                                                                                                                                              15
                             Poor-Quality
                                                                                                                                                                         Typical-Quality
                  10
                                                                                                                                                              10

                   5
                                                                                                                                                               5
   Force (kips)




                                                                                                                                               Force (kips)
                   0
                                                                                                                                                               0

                   -5
                                                                                                                                                               -5

                  -10                                                                                                                                         -10

                  -15                                                                                                                                         -15
                        -3           -2     -1          0             1                         2           3
                                                                                                                                                                    -3             -2      -1          0            1   2   3
                                                 Displacement (in)
                                                                                                                                                                                                Displacement (in)
                                                                                    Superior-Quality (Concrete Stem Wall)
                                                                                    15
                                                                                               Superior-Quality
                                                                                    10

                                                                                     5
                                                                     Force (kips)




                                                                                     0

                                                                                     -5

                                                                                    -10

                                                                                    -15
                                                                                          -3           -2         -1          0            1                   2               3
                                                                                                                       Displacement (in)
CUREe-Caltech Woodframe Project, Element 1 - Research Meeting, January 13, 2001




                      Schedule for Task 1.5.4
                                                                                  2001
                        Tasks                    O      N      D      J      F     M     A   M
        Coordination Meeting with Task 4.1
        Perform Analyses of Index Buildings
        Final Report

								
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