The Project Design And Deformation Analysis Of Deep Excavation Applying The Pile-Anchor & Soil Nail Wall

Deep foundation project is a complex engineering problem with characteric of complexity,comprehensive and high-risk. It involved with geological conditions, climatic conditions,surrounding environment, technology and level of management. Pile-anchor supporting systemhas been widely used in design of deep foundation pit due to its lower cost, safty and reliability.Overbreak, overload, leak of pipeline, delay of warning and lack of experience have seriouslycaused project monitoring accident and resulting in severe economic and property losses. It’simproper to simply rely on the theoretical design and on-site monitoring with out in-depth analysisso as to meet the requirement of the complex surrounding environment and geological conditions.More and more experts and scholars begin to call for the establishment of a scientific, economic,efficient information-based management system to guide the construction work.This article combining with a deep foundation excavating and supporting process in beijing. Adetailed scheme of process monitoring and safty warning methord of horizonal displacement alongthe depth of the piles, settlement of top piles and axial force of pretensioned anchor cables isdesigned according to the technical specification, excavation depth, engineering geologicalconditions, surrounding environment and other factors. Through the collection and analysis ofmonitoring data, investigation on the structural internal force, deformation characteristics andstability of the slope is carried out accordingly carried out. In addition, the effect ofthree-piles-two-anchors retaining system used in sand and gravel stratum foundation pit issummed.With the help of FLAC3 D software which based on finite difference method to simulate pitexcavation and make scientific analysis. Establish proper stratigraphic model and set a reasonableboundary conditions according to the engineering geological survey data, then selecting Cable unit,Pile unit and Beam unit of FLAC3 D software to simulate supporting structures and null element tosimulate process of pit excavation. Recording the maximum unbalanced force and internal forceand deformation of each unit when excavation simulating layer by layer. Finally, comparing thesimulation data and monitoring results to verify the pit slope stability, and provide a designreference for the similar projects in future.