Numerical Simulation Of The Pile-Anchor And Soil-Nailing Combined Structure In Deep Foundation Pit Supporting

With more high buildings and substructures constructed,the deep foundation projects are becoming more and more.The design and construction of excavation are becoming more difficult.Under the assurance of the foundation security ,how to reduce the protecting cost as far as possible has become a important question which foundation protecting designer must solve.deep foundation pit is a complex geotechnical engineering question,which is complex skill and comprehensive, related to safety, environmental,economic,construction period other aspects.So, how to design a safe, reasonable and feasible foundation pit support,has became the domestic and international problem of common concern.A successful foundation excavation design must be done with the combination of engineering investigation,supporting design,site monitoring ,construction management and dynamic analysis.Foundation design theory behind the engineering practice,easy to cause significant economic waste and engineering accidents.In view of the questions on design of deep foundation pit and the Experiences in the construction process,In this paper, using the method which combining theoretical guidance, project examples and numerical analysis ,in order to make a comprehensive analysis for the design of foundation pit pile-anchor and soil nailing combined supporting structure ,and give my own suggestion,so to guide better project design and engineering practice. Summed up a practical optimization approach.Main results as follows:(1)According to the existed related code in our country, based on the summary of the related literature,this paper analyzed the earth pressure model,The optimization and deformation control standards was given.(2) Pile-anchor and soil nailing was the important part,the parameters of upper soil nailing were chosen to meet the stability of upper soil;the position of pre-stressed anchor affected the inner forces of supporting structure directly, increasing the value of pr-stress of anchor was the most effective method for deformation controlling, The stiffness and depth of piles affected the whole stability.(3)With a LIZHENG deep pit design software,this paper optimized and designed Supporting structure,give the supporting foundation design and the value of the displacement and subsidence. (4) According to the specific projects examples, use optimization theory to optimize the design of deep foundation, and apply FLAC^3D numerical simulation to solve the optimized solution,the contour of displacement and stress fields of support regional was given.This article combined with the projects examples,numerical simulation,design theory and construction practice, offered an effective method for the design optimization of deep pit.