Analysis on measured deformation performance of 45m class ultra-deep foundation pit project in soft soil layer
With the background of a 45m calss ultra-deep foundation pit project in Shanghai soft soil area,its measured deformation performance were analyzed.The results show that lateral displacement of the diaphragm wall increase with the increase of excavation depth,and the spatial effect of deformation is quite significant.The maximum lateral displacement of diaphragm wall is quite large due to the large excavation depth,the ration of the average value of maximum lateral displacements and the excavation depth was only about 0.43%,which was quite close the statistical average value of deformation of foundation pitfor excavation depth less than 30m in Shanghai district.Diaphragm walls and columns are affected by excavation unloading,the vertical displacement is shown as bulging,and the bulging value tends to stability under the condition of base slab pouring,and the maximum rebound of columns reaches 65mm.The increment of axial force of each course of support basically occur in the excavation condition of the soil body immediately below,and the maximum axial force value basically occurred in the sixth,seventh and eighth course of support.The ground surface settlement outside the foundation pit is"concave shape",and the surface settlement gradually increases with the construction phase,and the location of the maximum settlement gradually develops to the outside of the pit,while the dimensionless ground surface settlement is still within the statistical settlement envelope of the soft soil area in Shanghai.In addition,the deformation of the pipelines around the foundation pit and the maglev are small,indicating that the foundation pit works are safe and controllable.
ultra-deep foundation pitsoft soildeformation performancedeformation of diaphragm wallground surface settlementdeformation of building and structure
NETL
NSTL
万方数据
