Analysis Of The Deep Excavation Construction And The Effect On Adjacent Buildings

In recent years，as a result of urban underground space development and rail transitconstruction, environmental conditions surrounded subway station foundation pit are more andmore complex. It’s a severe challenge for design and construction methods of foundation pitengineering to protect adjacent buildings. Though there are many analysis on interaction effectof foundation pit engineering and the surrounding environment and building. But the affect onadjacent buildings by foundation pit excavation construction still need to further discussed.According to the geotechnical engineering investigation report of subway station project，design and construction programme，surrounding traffic，adjacent buildings is fully to besummarized. The3dimension numerical models of construction process of foundation pitexcavation are established. The Mohr-coulomb elastoplastic constitutive model is assumed tosoils. The deformation of the foundation pit, the axial forces of concret and steel bracing, thecharacteristic of surface soils settlement，the deformation of retaining structure and the upliftdeformation of bottom soils are analyzed. The behavior of concret and steel bracing axialforces influenced by construction process are summarized. Further，the finite element model isestablished for the effect on different structural type of adjacent buildings by construction offoundation pit excavation. The change of the settlement of adjacent buildings foundation, thedisplacement and the internal forces of the superstructure are studied. The detailed analysis aresummarized on adjacent buildings deformation of different superstructure and differentfoundation. The characteristics of superstructure internal force of adjacent buildings areanalyzed. The main conclusions are as follows:(1) Foundation pit excavation programme have significant effect on the soil surfacedisplacement，retaining structure deformation and support structure internal force. Themaximum surface settlement is at the edge of the foundation pit. The position of the maximumhorizontal displacement of retaining structures is influenced by space effect of the foundationpit. The axial forces of bracing have obvious changes along with the excavation process.(2) The foundation settlement of adjacent buildings is caused by foundation pit excavation construction. The different settlements of foundations of three typical buildingstructure have no significant effect on the internal forces of the structure. The superstructureshave no obvious deflection.(3) According to the deformation characteristics of adjacent buildings affected by thefoundation excavation construction, the influenced area of settlement, horizontal displacementof adjacent buildings foundation, and the influenced area of uplift deformation of bottom soilsthe of foundation pit by foundation pit excavation construction are concluded.