Stability Of Foundation Pit With Pile Supporting In Karst Area

With the vigorous development of China’s infrastructure,highway,railway,subway,housing construction and other projects often encounter karst caves,caves will sometimes seriously affect the safety of the project,or increase the cost of the project or the impact of time limit.However,for the impact of small caves,designers often rely on engineering experience to propose solutions or not to deal with.In this paper,the three-dimensional cavity model is established by finite element software,and the influence scope of small karst cave on the supporting pile of foundation pit is analyzed.The main contents of this paper are as follows:(1)in the three-dimensional model of pile bottom branch of cave,cave distance were simulated in different depth of pile bottom for retaining pile horizontal displacement of pile top and pile settlement,retaining pile after ground subsidence and uplift effect;(2)is located in the active area of three-dimensional model of retaining pile up cave,cave in rock are simulated in different depth and distance related effects of retaining pile cave at different distances,analysis of retaining pile horizontal displacement,pile settlement,retaining pile after ground subsidence and uplift effect;(3)in the three-dimensional model of the passive zone of retaining pile up cave,cave in rock are simulated in different depth and distance related effects of retaining pile cave at different distances,analysis of retaining pile horizontal displacement,pile settlement,retaining pile after ground subsidence and uplift effect;(4)through the analysis of model results,determine the necessity of a Karst Treatment in practical engineering,and simulate the practical project to verify,in order to ensure the stability of supporting pile and foundation pit under the premise,to determine the treatment plan of the cave.The related research results can predict the deformation of foundation soil,provide the basis for the layout of monitoring points;affect the scope of the study,can provide guidance for engineering construction;research methods and results can provide experience for the similar projects in the future.