基于FLAC3D的基坑支护三维数值模拟分析

发布时间：2018-04-22 06:18

本文选题：基坑工程 + 预应力锚索支护体系　；参考：《辽宁师范大学》2013年硕士论文

【摘要】：随着社会经济的飞速发展，城市建筑趋向高层化，地下空间需要充分开发和利用。地下室由一层增加到多层，相应基坑的开挖深度也增大到地表以下几十米，由此，在城市中产生了大量的基坑工程。基坑工程作为整个工程的基础，直接影响到主体工程的安全、进度及质量，这就需要采取相应的措施来加固基坑，以保证整个工程的顺利完成。目前，预应力锚索在基坑加固过程中的计算理论和方法还停留在刚性理论的极限平衡法，对基坑边坡的变形机理认识不够，将基坑侧壁当作刚体考虑而不是变形体，同时依靠实践经验来分析和设计。如今，数值模拟技术的不断发展，为基坑支护工程的分析与设计提供了一条新的途径。本文依据具体工程实例，采用理正稳定性分析软件和FLAC3D软件两种不同工具分别对基坑支护工程的C’-D段进行模拟、分析；再将现场实际测量的数据进行整理，最后将三者的计算结果进行对比分析，进而更加准确的分析基坑边坡的稳定性，验证设计方案的可行性和正确性。本文的具体内容如下：（1）概述了基坑工程在国内的发展状况及预应力锚索在基坑加固中的作用及原理；（2）分析和总结土压力的计算理论，给出各个计算理论的适用条件，为以后的软件计算奠定理论基础；（3）简单介绍了FLAC3D的基本原理及应用范围，特别对其锚索单元的模拟作了详细的介绍；（4）运用理正稳定性分析软件对基坑C’-D段进行计算，得出设计方案，并且对照相关规范，验证该设计是否具有可行性；（5）在理正稳定性分析软件计算基础上，采用FLAC3D软件对基坑C’-D段进行两次不同的（支护前、后）三维数值模拟，直观、准确的反映出基坑内部介质的受力及位移变化情况，，体现出预应力锚索支护体系在基坑加固中所起到的作用；（6）结合现场监测的数据，将FLAC3D的计算结果、理正软件的计算结果和现场实测数据进行对比分析，从而验证FLAC3D数值模拟的正确性和有效性，为今后的工程设计和施工提供有价值的参考。
[Abstract]:With the rapid development of social economy, urban buildings tend to be high-rise, and underground space needs to be fully developed and utilized. The basement has been increased from one floor to many layers, and the excavation depth of the corresponding foundation pit has increased to several tens of meters below the surface of the earth, thus, a large number of foundation pit projects have been produced in the city. As the foundation of the whole project, the foundation pit engineering directly affects the safety, progress and quality of the main project. Therefore, it is necessary to take appropriate measures to strengthen the foundation pit to ensure the smooth completion of the whole project. At present, the calculation theory and method of prestressed anchor cable in the course of foundation pit reinforcement still remain in the limit equilibrium method of rigid theory, the deformation mechanism of foundation pit slope is not well understood, and the side wall of foundation pit is considered as rigid body instead of deformable form. At the same time rely on practical experience to analyze and design. Nowadays, the development of numerical simulation technology provides a new way for the analysis and design of foundation pit support engineering. In this paper, according to the concrete engineering examples, the Ca-D section of the foundation pit support engineering is simulated and analyzed by two different tools, namely, the straightening stability analysis software and the FLAC3D software, and then the actual data of the field measurement are sorted out. Finally, the calculation results are compared and analyzed, and the stability of foundation pit slope is analyzed more accurately to verify the feasibility and correctness of the design scheme. The details of this paper are as follows: 1) the development status of foundation pit engineering in China and the function and principle of prestressed anchor cable in foundation pit reinforcement are summarized. 2) analyzing and summing up the calculation theory of earth pressure, giving the applicable conditions of each calculation theory, and laying a theoretical foundation for the later calculation of software; The basic principle and application scope of FLAC3D are briefly introduced, especially the simulation of anchor cable element is introduced in detail. 4) calculate the Ca-D section of foundation pit by using the software of Li-positive stability analysis, obtain the design scheme, and verify the feasibility of the design compared with the relevant codes. Based on the calculation of rational positive stability analysis software, FLAC3D software is used to carry out two different three-dimensional numerical simulations of Ca-D section of foundation pit (before and after support), which can directly and accurately reflect the change of stress and displacement of the inner medium of foundation pit. The function of prestressed anchor cable support system in foundation pit reinforcement is reflected. In order to verify the correctness and validity of the FLAC3D numerical simulation, the FLAC3D calculation results, the calculation results of the straightening software and the field measured data are compared and analyzed in combination with the field monitoring data. To provide valuable reference for future engineering design and construction.
【学位授予单位】：辽宁师范大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU470

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