Support Design And Analysis Of The Foundation Pit In A Building

Along with the development of city building, high buildings are more and more,appearing a flood of deep excavation engineering projects. For safety of the surroundbuildings, underground tube line, road etc during excavation and stability of the slope ofexcavation, it is necessary to the analyze stability of slope and study the manage project ofinstable slope in deep excavation.The building covers an area of21230m2with on the ground is thirty-three layer andunderground is two layer. It is the framework of shear wall structure. The works are basedon depth of8.2m, the actual excavation depth is8.5m. In the pit supporting the designprocess, there has analyzed four types of scheme one after another:1. Cantilever pilesupport;2.cement-soil wall3. Soil nail wall4. Pile in row single-Fulcrum care. Thecantilever piles supporting is unreasonable. Soil-nailing wall support is usually to be usedfor shallow pit. Initially conduct pit sealing and precipitation design and anti-pipingchecking. And then processed to the calculation of earth pressure， including theactive-earth pressure, passive-earth pressure, and the pure-earth pressure. Draw theearth-pressure maps. Determine the parameters of the soil-nail wall. Then conduct internalstability, external stability and soil-nail pullout resistance checking. The checking resultsmeet the requirements. And use deep-foundation software to calculate with computer. Atlast finish the excavation-support design.As the nail length is generally smaller than the length of the bolt andnon-prestressed，it has simple equipments. The cost of soil nailing wall are lower thanother supporting structure. Less noise, less vibration and no impact on the environment.The soil nailing wall deformation is small, has little effect on the adjacent buildings.