Analysis Of Surface Subsidence Of Beijing Subway Station With PBA Method

As the construction of subway, the conditions of subway station construction areincreasingly complex. For geological conditions of ground traffic busy and complicatedunderground pipeline, the PBA (Drift-pile method) in the construction of metro constructionis usually preferred solution. Of course the PBA (Drift-pile method) will inevitablydisturbance on the ground. Studying the PBA method construction impact on surfacesubsidence is significant to the safety of the structure itself and the surrounding existingstructures. This article is set in Beijing metro engineering construction example，using thefinite element software (MIDAS-GTS) to analysis the PBA method construction procedure.And compare the results of numerical simulation and the actual monitoring data, thecorrectness of the numerical simulation is verified. To predict the final settlement of theearth’s surface at the same time, analysis the PBA method in the whole process of impact onsurface subsidence. And the different scheme of pilot tunnel excavation influence on surfacesubsidence.The main research content is as follows:1. Based on actual project, as well as by MIDAS GTS3d stratum structure model, simulatingthe actual working condition of excavation, and comparing the numerical simulation resultswith the actual monitoring results, so as to verify the reliability of the results of numericalsimulation.2. In the actual monitoring data and numerical simulation results are basically identical, toforecast the final settlement value of the surface of the earth. At the same time researching thestation’ PBAmethod of each construction process impact on surface subsidence,as well asthe influence of the structure itself. Summing up the PBA method impact on surfacesubsidence laws. 3. According to the actual monitoring data, discussing different pilot tunnel excavationsequence of different effects on structure itself and the surface subsidence, comparingdifference, choose a better solution, provides reference for actual construction.