基坑底板施作后降水渗流对基坑变形影响规律OA

With the increasing demands for urban underground space development and construction,both the exca-vation area and depth of foundation pit projects have been steadily rising.The impact of precipitation on the defor-mation and stability of foundation pits has become increasingly prominent.In order to investigate the deformation characteristics of foundation pits under different precipitation depths after the bottom slab construction,the founda-tion pit project of the comprehensive transportation hub at Beijing Municipal Administrative Center Station is taken as an example.A detailed numerical analysis model is conducted by the finite element software Midas GTS NX to systematically explore the deformation characteristics of the foundation pit and diaphragm wall under different pre-cipitation conditions.The study showed that the depth of precipitation had a significant effect on the settlement de-formation at the top of the foundation pit.The settlement deformation of the foundation pit caused by precipitation increased by 55％than the one without precipitation;With the increases of precipitation depth,the surface settle-ment gradually increased.And the closer to the side of the foundation pit,the larger the surface settlement;When precipitation reached the bottom of the foundation pit,the settlement of the foundation pit at 0 m from the pit edge increased by 57％than the one at 100 m;The depth of precipitation had a greater effect on the vertical deformation of the diaphragm wall.When precipitation reached the bottom of the foundation pit,the overall vertical displace-ment of the diaphragm wall increased by 76％than the horizontal displacement.