地铁车站明挖基坑围护结构稳定性的研究.pdf

西南交通大学硕士研究生学位论文第l页摘要随着经济社会的快速发展,地铁对城市功能的合理布局,如城市规划、交通、经济乃至社会环境等都将起到积极的作用。地铁建设首先面临的问题就是地铁车站围护结构的稳定性。深基坑是地铁车站的基础,保证基坑工程的安全性具有重要的经济和社会效益。基坑变形受到多种因素的影响,如土体力学参数、支撑力的大小、连续墙设计、支撑预应力大小等,因此基坑稳定性成为研究的热点问题。目前国内外对基坑变形估算的方法主要包括有限单元法、地层损失法和估算法,有限元法可以考虑各种因素对变形的影响,并且可以精确的预测基坑的各种变形,因此有限元法必将成为基坑变形计算的主要方法。本文拟对地铁车站围护结构的稳定性问题进行数值模拟研究。论文首先分析了深基坑稳定性的重要性,探讨了深基坑稳定性的计算方法,并研究了其在深基坑围护结构变形预测方面中的应用。论文采用Midas 6TS有限元计算软件对哈尔滨医科大学附属第二医院地铁车站深基坑进行了数值模拟。主要研究了围护结构稳定性的几个关键问题: (1)准确的数值模拟研究是研究稳定性的先决条件。(2)对数值模拟计算结果进行分析(3)对影响深基坑围护结构稳定性的各项因素进行分析。论文通过对上述问题的研究,来解决地铁车站围护结构的稳定性,可为今后类似地质条件下地铁车站工程的设计提供参考。关键词:地铁车站;深基坑;围护结构;数值分析;稳定性; Abstract With thedevelopment ofeconomy of our country,subway plays avitalroleinoverall arrangement of acity,such ascityplanning,traffic,economy andenvironment and SO on. Theprimay taskinconstructing subway is tomaintain thestability ofenclosure structure of subway excavation isfundamental basis ofsubway ensure its security isofsignificant economic and socialbenefit. Pitdeformation isinflunenced bymany factors,such assoilphysical parameters,the sizeofsupport force,thedesign ofdiaphragm wall,the sizeofsupport prestressing and SO stability ofpit es aresearch present,the calculation methods ofpit deformation atall over theworld include finiteelementmethod,the soillosstheory and equivalent method,of which thefiniteelementmethod can takealldeformed factors into consideration and predict allkinds ofdeformation ,this paper willmake use of finiteelementmethod asprinciple calculation method. This thesisstudies thestability oftheenclosure structure ofsubway station byusing numerical simulation. Inthisthesis,the importance ofthestability ofdeep excavation was analyzed,the calculation methods were discussed and theapplication ofthedeformation oftheenclosure structure ofdeep exaction was studied. By using thecalculation software ofMidas GTS,numerical simulation was carried out to research the deep excavation of subway station in2nd affiliated hospitalof