【作者】 陈竹涛；

【导师】 刘新荣；

【作者基本信息】 重庆大学 ， 岩土工程， 2006， 硕士

【摘要】 城市地下空间的开发利用是中国城市化的必然要求,作为城市的基础设施和灾害防御设施的城市有轨交通系统是城市地下空间利用中很重要的一个方面。随着我国社会经济的发展,在城市人口密集区地下修建大跨度的车站隧道工程将会越来越多。论文首先对重庆轻轨大坪车站隧道监控量测数据进行处理,然后论述了大跨浅埋扁平隧道的开挖后的应力重分布状况和大跨扁平隧道围岩稳定性的判断标准;并用大型有限元分析软件ANSYS对大跨浅埋扁平隧道的几种施工工法进行了二维和三维数值模拟,从地表沉降、应力集中以及塑性区分布等多方面优化出最为适合的施工工法;监控量测处理结果同数值模拟结果对比分析表明,数值模拟分析结果基本同监控结果一致。通过研究获得如下主要成果:1.通过对重庆轻轨大坪车站隧道的监控量测数据处理分析,对隧道的净空、地表、拱部和支护结构受力进行了研究分析,得到了地表、拱顶以及支护结构的数值变化曲线,拟合了隧道净空收敛回归曲线。2.对几种常见洞室—圆形洞室、椭圆形洞室和卵形洞室开挖后的应力重分布进行了分析,并结合大跨扁平隧道的特点,阐述了影响隧道围岩稳定性主要因素与判定依据。3.隧道模型二维数值模拟从拱顶沉降与水平收敛、支护结构内力、围岩塑性区分布等方面优选出最为适合大坪车站隧道施工的施工工法。4.三维数值模拟显示了围岩二次应力重分布和支护结构的应力变化随施工进深的变化趋势,拱脚在施工掌子面进展到6m之后其拱脚应力集中达到最大值;拱顶沉降在施工掌子面进展到9m之后其沉降值达到最大值,故控制6m的施工进深然后做拱部全断面的二次衬砌是十分必要的。更多还原

【Abstract】 The exploitation city underground space is very necessary for Chinese urbanization, and railroad traffic system which is city’s basic urban establishment and recovery disaster establishment is the most important part of urban underground utilization.With the development of economy, large span and shallow-buried tunnel in the center of city will appear more and more.The article firstly handles the data for monitor and control of Chongqing light rail Daping station tunnel, secondly analyses stress distribution of surrounding rock and expatiates construction methods of large span and shallow-buried tunnel. By making simulation and analysis to several construction methods for large span and shallow-buried tunnel through ANSYS software, educes the most reasonable method by comparing the surface subsidence and stress convergence. By comparison, the data of monitor and control is consistent with the data of numerical simulation.Through study, conclusions are as follows.1.Through ground surfacehrough the data processing of Chongqing light rail large Daping station tunnel’s monitor and control,anlyses tunnel’ headroom, ground surface, vault and shoring structure stress,get clearly terrene, vault and shoring structure’s change in value curve,fits tunnel’s headroom convergence regression curve.2.To several cavities,such as circular cavity、oval cavity and olivary cavity, anlyses surrounding rock stability,and expatiates major factors which impact tunnel surrounding rock stability and determinant gists by considering the chacteristics of large span and flat tunnel.3 Tunnel’s numerical simulation, from vault sedimentation and horizontal convergence, shoring structure stress, surrounding rock plastic zone distribution aspects, optimizes the fittest construction method.4.3D numerical simulateion of arch shows the trend of wall rock secondd afresh distributing and timbering shoring stress movement. Skew back stresss reaches maxima when tunnel heading heads 6 m. The vault sedimentation maximizes behind tunnel heading reaching 9m,So 6m construction throat is necessary.更多还原