Question

For the redevelopment project (shown in the following page), it is planned to back fill up the south side of the existing 5 story building (it is a hundred years old stone exterior building) to and over the third-floor level to create additional parking spaces, which was estimated that will create a soil mass with the maximum height at 40 ft (see attached Section ). The existing building exterior was not reinforced and with large window openings. It is understood that all of the windows below the third floors will be covered. Nevertheless, the most important factor to be considered for this part of the project is to reduce or eliminate the lateral force acting on the exterior wall of the building. Several methods can be considered; such as ground anchor/tie back, to use Engineered Polystyrene (Styrofoam) as light weight fill, just to name a few. You are retained as the Geotechnical consultant for this project to answer the following questions:

1.    Based on the given conditions and restraints, recommend a retaining structure system for this project. You must show both why the systems were not recommended and more importantly why the specific system was selected.

2.   After you have come up with the retaining structure system to be used. You are then required to show the design of such a system.

3.   Between the building exterior and recommended retaining structure, should there be any additional geotechnical treatment needed? If so, what would you do? (this is outside of the coverage of this course, it will be count as bonus credit and you are encouraged to elaborate your response.

The in-situ soil is the type of SC-SM with a reference unit weight of 125 pcf and the drained shear strength (internal friction angle) of 30 degree, which will be used as the fill material for the structure in question.

Image transcription text

The in-situ soil is the type of SC-SM with a reference unit weight of 125 pof and the drained shear strength (internal friction angle) of 30 degree, which will be used as the fill material for the structure in question. N EXISTING 5 STORY STRUCTURE Proposed Parking area T. W. = 112.8 ((B. W. = 99)) F.W.= \$10.0 (B. W. = 94) B. W. =_116.0 LY.W= 131.0 B. W. = 124.9 CORNER OF WALL B. W. = 122.0

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