Ft Benning- Civil Narrative 10.3

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Ft Benning- Civil Narrative 10.3 Powered By Docstoc

Per Tab C

(ee)      Grading

The total limits of construction are approximately 5.0 acres which will mostly be disturbed.
The following measures shall be implemented to minimize pollutants in storm water
discharges associated with construction activity at the construction site: stabilized
construction entrance, silt fence, temporary sedimentation basin/traps, stabilization of
existing slopes and green space with seed and mulch and other miscellaneous sediment
control devices to assist in the control of sediment. Runoff from the project site will be
conveyed via sheet flow to collect/contain sediment from leaving the project site. All
erosion and sedimentation control measures with be in accordance the Manual for Erosion and
Sediment Control in Georgia.

The project site is a very challenging site with existing elevations ranging from 330 feet to the
north near the limits of construction to approximately 280 feet along 11th Airborne Division
Road. The site will contain a retaining wall along the west and north side of the side in order
to accommodate the great change in elevation. The site will be graded to provide a Finished
Floor Elevation (FFE) for the Central Issue Facility (CIF) building of 299.50 feet.

The proposed site grading will provide positive drainage away from the buildings and will
direct runoff to the onsite storm water management areas via sheet flow, grassed swales and
a closed storm pipe collection system to the proposed stormwater basin located in the
southeast corner of the project site. Slopes across grassed areas and parking lots will be a
minimum of 1%. Curb and gutter as noted on the plans will be used to direct runoff to the
proposed stormwater basin.

The site‟s storm water management system is composed of a stormwater basin. Runoff from
the west side of the project site will be conveyed via sheet flow and closed storm pipe
collection system to the stormwater basin located on the southeast corner of the site. Also,
runoff from the east side of the project site will be conveyed via sheet flow and grass swales
to the stormwater basin. The parking lot area runoff, south of the CIF building, will be
routed via sheet flow and closed storm pipe collection system to the stormwater basin. A
roof drain collection system will be provided to collect runoff from the roof and tie in to the
closed storm pipe collection system.

The storm water management design will provide storm water quantity control that will
attenuate post-development flows to pre-development rates of the 2- and 10-year, 24-hour
storm event in an effort to achieve LEED–Silver requirements. Before discharging the runoff
off-site, the storm water will also be treated for storm water quality by use of onsite Best
Management Practice Facilities (BMPs) in accordance with Georgia Department of Natural
Resources (GADNR) and Fort Benning standards and specifications.

The geotechnical evaluation provided by the Soils Section Geotechnical & HTRW Branch of the
US ACOE indicates the site contains layers of poorly graded sands (SP), silty sands (SM), clayey
sands (SC) and clays (CL or CH). The report notes that there are loose soils at elevations that
may be impacted by the project and recommend that these loose soils be densified where
needed prior to construction. The US ACOE recommends that once the building pad and
pavement locations are determined, supplemental geotechnical exploration be performed to
better quantify the extent of unsuitable soils and how they will impact the structure and

(ff)    Landscaping

All landscape materials will be in accordance with Fort Benning‟s plant list and will include
Crepe Myrtles, Red Maples and Yaupon Holly shrubs. The shrubs will be provided along all
concrete pathways to prevent „short-cutting‟ outside the designated pathway surfaces and
extend at least 15 feet from the intersection edge along each pathway. The trees will be
limited to areas outside of the 33 foot AT/FP setback in the parking lot area to provide
aesthetics to the building and areas surrounding the site. All other pervious areas within the
project will be seeded in accordance with Fort Benning turf and seeding requirements. All
other grassed areas will be hydroseeded.

(gg)    Pedestrain Circulation

Portland Cement Concrete sidewalks will be provided to allow pedestrian circulation and
access around the new administration area, warehouse/storage and the parking area. A 15‟
sidewalk is provided at the main entrance and raps around the administrative portion of the
building. All other sidewalks are noted on the plans.

All Privately Owned Vehicular (POV) circulation will be located outside of the 82‟ ATFP
setback for the proposed CIF building. The POV parking lot will be connected via sidewalk to
the proposed building.

(hh)    Vehicle Circulation

All POV parking for the new CIF building will be provided west and south side of the
new building adjacent to the administrative area. The parking area will be sized to
accommodate 50 parking spaces per the RFP requirements.           Three of the spaces will be
handicap spaces.
The drive aisles of the parking area will be 24-foot wide to accommodate 2-way traffic. This
parking lot will be designed to provide adequate vehicle circulation and movements in
accordance with AASHTO design standards. In addition, a bus parking/loading area has been
provided to accommodate people accessing the building. The drive aisle for the bus drive
lane will be 20-feet to accommodate bus traffic. This parking lot including bus parking area
will have two points of egress/ingress from 11th Airborne Division Road.

Truck delivery/delivery access to the building will be accessed from 11th Airborne Division
Road. Circulation for warehouse delivery vehicles will be provided west of the new building
adjacent to the loading dock area. This entrance will be secured with an access gate.

A new dumpster pad and enclosure will be constructed with exterior to match the appearance
of the proposed building. The pad and enclosure will be sized to accommodate one (1)
dumpster for recycling and one (1) dumpster for trash. The new dumpster pad and enclosure
will be constructed in an area to provide convenient access from the Administrative and
Loading portions of the building. The location of the new dumpster pad has been placed in
location for accessible.

Bicycle racks will be provided on site in close proximity to the building and in accordance
with Fort Benning design standards.

(ii)    Anti-Terrorism/Force Protection

The design of the proposed CIF building will be in accordance with UFC 4-010-01
Antiterrorism/Force Protection (AT/FP) requirements. The building is assumed to be
considered a “Primary Gathering” facility for the administrative areas and “Inhabited
Building” for the warehouse/storage areas. An 82-foot standoff distance will be provided
from all public access drives and parking areas. Security gates will be installed at the loading
area entrances to prevent unauthorized vehicles from advancing beyond the 82-foot standoff
distance. In addition, collapsible bollards will be provided at the emergency fire access drive
located south of the new building.

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