The Research On Under Complex Conditions Of Large Deformation Forecast And Control Technology In Soft Soil Area

Along with the development of urban three-dimensional space, there appear a large number of deep excavation.Foundation pit excavation engineering involves the safety, underground engineering itself of foundation pit the use function to the specific requirements of the surrounding buildings and pipelines and safety, etc. Based on Shanghai urban large underground pump station grass sand comprehensive key technology research project construction, the fem numerical simulation and engineering field monitoring data contrast method, according to stratum study method of thinking loss.This paper numerical model of soil by elastic-plastic model with assumption, its yield criterion by DP criterion, palisade structure and supported with linear elastic hypothesis, established the foundation pit excavation of the 2-d fem step. The main computing the foundation pit excavation construction stage in different soil, support, and process of the internal force and deformation of palisade structure, through comparison with the monitoring results verified analysis method is feasible.Through analysis on the calculation results, obtained the following results:(1) Analysis results show that the size, depth of varying excavation group, different construction excavation schemes, cause the palisade structure of the internal force and displacement are different. And there is a relatively optimal excavation scheme, can to save costs, reduce project risk purpose;(2) Through numerical analysis and field monitoring, concluded that the general rule of deformation;(3) Presented excavation numerical simulation predicted large foundation pit engineering construction cause deformation method on-site monitoring, and get a good ones;(4) the simulation results of effective analyzes the construction process of all kinds of risk factors, and put forward the corresponding control measures to ensure the safety of the project.