软土地层超深基坑施工变形控制研究

发布时间：2018-01-11 07:38

本文关键词：软土地层超深基坑施工变形控制研究　出处：《湖北工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着城市建设的飞速发展,地铁和高层项目与日俱增,大量的深基坑项目随之出现且凸显出规模超大、开挖超深、几何尺寸不规则、场地狭小、环境复杂敏感等特点,从面使得对控制基坑施工过程中变形的难度不断增加。论文以武汉某深基坑项目为依托,对基坑变形控制的施工技术进行系统的研究,主要研究内容如下:(1)根据已有的基坑资料,运用有限元软件Midas/GTS建立数值模型,模拟基坑开挖、支护过程中各种工况下支护结构的应力、应变、位移及周边地面沉降;(2)在支护结构地下连续墙施工过程中,形成了一整套施工关键技术,使地下连续墙的整体性和刚度得到了提高,确保其质量;在基坑开挖与支护结构施工过程中,通过岛式开挖,分块分层,限时支护,有效地减少了时空效应对基坑开挖的影响;(3)根据“按需抽水、分层降水、降水量最小化”的原则,采用控制降水量的管井降水技术,严格控制降水深度、降水量,减小对周围环境的影响;(4)在基坑开挖施工过程中,运用多种技术手段监测由于基坑施工引起的变形,并在监测数据的基础上,建立BP神经网络程序,预测基坑开挖变形,并建立安全评价模型,及时判别基坑是否处于安全状态,实现了信息化指导施工。通过以上多种基坑变形控制技术,成功的控制的基坑开挖引起的变形,保证了基坑开挖安全。论文的研究成果具有较好的实用价值,为武汉地区类似工程提供了借鉴。
[Abstract]:With the rapid development of urban construction, subway and high-rise projects are growing day by day, a large number of deep foundation pit projects appear and highlight the scale of super-deep excavation, irregular geometric size, narrow site. The complex and sensitive environment makes it more difficult to control the deformation during foundation pit construction. Based on a deep foundation pit project in Wuhan, the construction technology of foundation pit deformation control is studied systematically in this paper. The main research contents are as follows: (1) according to the existing foundation pit data, the finite element software Midas/GTS is used to establish a numerical model to simulate the stress of the supporting structure under various conditions during excavation and support. Strain, displacement and surrounding land subsidence; 2) during the construction of underground continuous wall of supporting structure, a whole set of key construction techniques have been formed, which can improve the integrity and rigidity of underground continuous wall and ensure its quality. In the process of foundation pit excavation and support structure construction, the influence of space-time effect on foundation pit excavation is effectively reduced by island excavation, block stratification and time-limited support. (3) according to the principle of "pumping water according to demand, stratified precipitation and minimizing precipitation", the precipitation technology of pipe wells is adopted to control precipitation depth and precipitation strictly, and to reduce the influence on the surrounding environment. 4) in the process of foundation pit excavation construction, various technical means are used to monitor the deformation caused by foundation pit construction, and on the basis of monitoring data, BP neural network program is established to predict foundation pit excavation deformation. And establish a safety evaluation model, timely distinguish whether the foundation pit is in a safe state, realize the information guiding construction. Through the above kinds of foundation pit deformation control technology, successfully control the deformation caused by foundation pit excavation. The research results of this paper have good practical value and can be used for reference for similar projects in Wuhan area.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU753

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