填海地区地铁车站深基坑围护结构变形与预测研究

发布时间：2018-01-23 05:28

本文关键词： 填海深基坑工程 MIDAS/GTS数值模拟咬合桩支护最小二乘支撑向量机　出处：《辽宁工程技术大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着沿海城市社会经济的快速发展,建设用地紧张和交通拥堵问题日显突出。采用填海造陆的方法解决建设用地紧张和修建地铁缓解地面交通压力已成为沿海城市发展战略中普遍采取的有效措施之一。填海地区特殊的地质和环境条件,使得其深基坑围护结构变形与其他软土地区深基坑支护结构变形有着明显的不同。本文在总结近年来国内外深基坑变形研究成果的基础上,依托大连海之韵地铁车站深基坑工程,采用理论分析、现场监测和数值模拟等综合方法对填海地区深基坑围护结构变形规律进行研究,采用基于MATLAB的最小二乘支持向量机理论对深基坑围护结构水平变形进行预测,得出了一些有价值的结论。本文的主要研究成果如下：(1)对大连海之韵地铁车站深基坑进行了现场监测,通过对现场监测资料进行分析,获得了围护桩水平位移变化规律和钢支撑轴力变化规律。结果表明,围护结构变形有着明显的时空效应,及时安装钢支撑和加快施工速度可以有效的控制基坑变形。桩顶向坑外偏移,是由于桩体弹性变形所致。(2)建立了海之韵地铁车站深基坑三维有限元模型,对围护结构变形进行了模拟计算,并将模拟结果与实测数据进行对比分析。结果表明,数值模拟所得水平位移曲线与现场实测所得水平位移曲线基本一致,现场施工过程中影响围护结构变形因素众多,曲线存在一定的差异性。分析了不同桩长对围护结构水平位移的影响,结果表明,入岩深度越大水平变形越小,但当入岩深度达到一定时,影响程度减小。(3)基于MATLAB工具箱,采用最小二乘支持向量机理论对深基坑围护结构水平位移进行预测分析。结果表明,采用最小二乘向量机可以对围护结构水平位移进行精度较高的预测,同时获得了深基坑围护结构水平位移的未来变化趋势,从而达到对围护结构早预测早控制的目的。
[Abstract]:With the rapid development of social economy in coastal cities. The problems of shortage of construction land and traffic congestion are becoming more and more prominent. To solve the shortage of construction land and to relieve the ground traffic pressure by building subway has become one of the most effective measures in coastal city development strategy. 1. Special geological and environmental conditions in reclamation areas. The deformation of retaining structure in deep foundation pit is obviously different from that in other soft soil areas. This paper summarizes the research results of deep foundation pit deformation at home and abroad in recent years. Based on the deep foundation pit engineering of Dalian Haizhiyun subway station, the deformation law of the retaining structure of deep foundation pit in reclaimed area is studied by comprehensive methods such as theoretical analysis, field monitoring and numerical simulation. The theory of least squares support vector machine (LS-SVM) based on MATLAB is used to predict the horizontal deformation of the retaining structure of deep foundation pit. Some valuable conclusions are drawn. The main research results of this paper are as follows: 1) the deep foundation pit of Dalian Haizhiyun subway station is monitored on the spot, and the site monitoring data are analyzed. The variation of horizontal displacement and axial force of steel braces are obtained. The results show that the deformation of the retaining structure has obvious space-time effect. Timely installation of steel support and acceleration of construction speed can effectively control the deformation of foundation pit. The displacement of pile top to the outside of pit is caused by elastic deformation of pile. (2) the three-dimensional finite element model of deep foundation pit of Haizhiyun subway station is established. The deformation of the enclosure structure is simulated and compared with the measured data. The results show that the horizontal displacement curve obtained by the numerical simulation is basically consistent with the horizontal displacement curve measured in the field. There are many factors affecting the deformation of the retaining structure in the field construction, and there are some differences in the curves. The influence of different pile lengths on the horizontal displacement of the retaining structure is analyzed. The results show that the greater the depth of entry, the smaller the horizontal deformation. But when the depth of the rock reaches a certain depth, the influence degree is reduced. 3) based on the MATLAB toolbox. The theory of least square support vector machine (LS-SVM) is used to predict the horizontal displacement of the retaining structure of deep foundation pit. The results show that the LS-SVM can predict the horizontal displacement of the retaining structure with high accuracy. At the same time, the trend of horizontal displacement of retaining structure of deep foundation pit is obtained in the future, so as to achieve the purpose of early prediction and early control of retaining structure.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU753

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