Numerical Simulation Analysis and Engineering Practice of Deformation Control of Ultra-deep Foundation Excavation Under Eccentric Load of Tidal Wave Zone
With the continuous development of underground space in China,there are increasingly more underground engineering projects crossing or adjacent to rivers.Such projects are often accompanied by the unique environment of the project adjacent to the mountains and rivers,whose deformation mechanisms and influence effects of deep foundation pit engineering are not clear,and their relevant control methods are rarely studied.Based on a municipal tunnel project adjacent to the Qiantang River in Hangzhou,the seepage law of the tidal wave zone was systematically studied.The numerical simulation analysis of the deformation of the 36.4 m ultra-deep and large eccentric load foundation pit was carried out,the corresponding deformation control method was proposed,and engineering practice was carried out.The research shows that by relying on the theoretical analysis and numerical solution of the water level monitoring data inside and outside the foundation pit of the project,the spatial and temporal evolution model of the seepage field of the foundation pit is established.It is known that the head attenuation is large when the tidal water enters the soil boundary.In the seepage path,the head change is stable,the groundwater near the foundation pit has an obvious lag in response to the tidal cyclic load,and high pore water pressure is generated around the foundation pit.Based on the modified Mohr-Coulomb elastoplastic constitutive model,a three-dimensional model for numerical simulation of deep foundation pit excavation under partial load and its surrounding environment is established using ANSYS software.To simulate the influence of the tidal wave zone,it is simplified to apply a 20kPa uniform load at the bottom of the foundation pit river.It is concluded that,compared with the ordinary environment,the deformation control of foundation pits under the influence of tidal power should be given more attention.Through three-dimensional numerical simulation and engineering practice,it is verified that the combined support form of"1 200mm underground continuous wall+5 concrete supports+2 steel supports"is an effective support countermeasure for an ultra-deep foundation pit near the Qiantang River.
tunnelsdeep foundation excavationtidal fluctuation zonepartial loadseepage fielddeformationsimulation
万方数据
维普
