Study On Numeircal Simulation And Monitoring Data Analysis For Deep Foundation Pile-anchor Of Changchun City West Railway Station

Foundation Pile-anchor of Changchun City West Railway Station.With the accelerated urbanization process in China, the scale of construction continuesto expand, high-rise, high-rise buildings are also increasing，but zhe land resources canbe used less and less, so underground space development and utilization of a large area.especially in the last10years, a large number of ultra-high floors, underground transferstation,underground construction drive the evolving deep excavations.Deep excavation works spread range, requires a multifaceted and holistic, and has astrong practical and risk.With the excavation depth increasing pit collapse of frequent, notonly affects the construction period, but also increases the project cost, has broughtgreat economic losses and negative social impact.Thus,given the complexity and riskof deep excavation,deep excavation safety in theconstruction process to monitor real-timedynamic deformation monitoring data feedback pit, to ensure the safety of the pit.With the continuous expansion of computer applications, numerical analysis andsimulation in engineering has been given a very good application, by simulating thedeep foundation pile-anchor deformation can fully consider the pit in the soil excavationand pile anchorcare in a variety of impact factor, proved the correctness of the monitoringprograms and field data.Based on the physical works-Changchun west railway station south square deepfoundation pit,the pile anchor deep excavation retaining structure deformation analysisand on-site monitoring of the numerical simulation. Through the establishment of thenumerical model,simulation analysis on envelope,and the deformation of the soil theoryto understand its trends, provide a basis to alert the value of setting and layout the sitepoints, From the changes of the measured data,according to the on-site monitoring cananalysis the deformation characteristics of the envelope structure and the soil in the construction process,which can timely and accurate monitoring information feedbackand guidance on-site construction envelope structure derived from the theoreticalanalysis and on-site monitoring deformation trend is consistent, which both sides canget better validation.1. Starting from the basic theory, by reading the extensive literature to understandthe pile-anchor supporting system, working principle and deformation characteristics,andthen stepwise to make mechanical analysis of pile-anchor,Finally,the actual pile-anchorproject method of calculation based on a hypothetical model to calculate.2. Take Changchun West Railway Station deep foundation pit for example, usingFLAC3D software through the basic assumptions, the structural parameters and boundaryconditions of the soil to support the establishment of a numerical model of the structure,unbalanced force on the pile-anchor the tophorizontal displacement, envelope piledeformation and anchor axial force simulation analysis,the Retaining Structure trend inevery step of the construction process, comeing to the simulation results with field dataare consistent.3. According to the results of theoretical analysis, developing a monitoring program,arranging the measuring points, monitoring methods and identifying early warningvalue.Through on-site monitoring data, analysis of soil stress in the construction processbuilding envelope displacement, pile distortion and Cable axial force changes anddistribution law, and by the state of security alert value which reflects the deep foundation.