广州某地下连续墙基坑支护效果分析

发布时间：2018-02-10 04:41

本文关键词： 基坑工程数值模拟地下连续墙监测数据　出处：《西安科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：选用地下连续墙开挖支护的基坑工程是目前工程地质领域重点研究的问题之一。探讨支护结构在开挖过程中的应力应变特征,达到更加有效的控制基坑在开挖过程中周围岩土体的变形控制。使开挖建设的基坑支护工程在安全稳定和使用功能满足各方面要求的同时,又能使经济节约这个目的得以满足,是当前工程界非常值得探讨的课题。基坑开挖造成的周围岩土体沉降变形和支护结构的偏移给周边建筑物造成安全使用隐患,使得人们得重视程度提高。在基坑支护工程开挖施工的过程中,圆形地下连续墙支护能够利用自身结构刚度大和土拱效应的特点,有效的规避或者减小对周边建筑物或者岩土体的扰动,以及控制对周围重要正在使用的建筑物安全稳定性的影响。其具体减小扰动程度量化分析值得深入探讨研究,在工程应用领域也有很高的实用价值。本文以圆形地下连续墙支护结构为研究对象。分析现场监测数据,进行数值模拟计算。总结周围岩土体沉降量和墙身偏移量两个关键变量的普通规律,得到如下几点成果:(1)分析现场监测数据,得到在1、2、3、7、8、9工况监测点处沉降量随基坑开挖深度增加而呈线性增长,增长速度略有不同,在4、5、6工况监测点处沉降量变化较小,甚至减小。在开挖深度范围内墙身偏移量随开挖深度增加呈线性增长,在开挖深度以下出现反向偏移,最大偏移量出现在2/3最终开挖深度处。(2)分析云图和模拟数据,得到地表沉降累计最大值的位置会随基坑开挖深度递增而向基坑外侧移动。基坑周边沉降量集中在距离基坑边缘0.5-1.0倍的基坑开挖深度处。随着基坑开挖深度逐层增加,墙身最大偏移量下移,且墙身偏移量折线图逐渐呈类似“S”型。同样能得到墙身最大偏移量出现在2/3开挖深度至坑底的附近区域内。(3)比较分析监测数据和模拟计算结果,得知有限元数值模拟可以有效计算分析圆形地下连续墙的周边沉降和墙身偏移量,预测类似工程周边沉降和结构变形,减少工程造价和提高施工监测准确率。
[Abstract]:The selection of underground continuous wall excavation is one of the most important problems in the field of engineering geology at present. The characteristics of stress and strain of supporting structure during excavation are discussed. In order to control the deformation of surrounding rock and soil in the excavation process more effectively, so that the foundation pit support engineering can meet the requirements of safety, stability and use, at the same time, the purpose of economic saving can be satisfied. The settlement and deformation of surrounding rock and soil caused by excavation of foundation pit and the deviation of supporting structure cause hidden danger for the safety of surrounding buildings. In the process of excavation construction of foundation pit support engineering, circular underground continuous wall support can make use of the characteristics of its own structure stiffness and soil arch effect. Effectively circumventing or reducing the disturbance to surrounding buildings or rock and soil, as well as controlling the influence on the safety and stability of buildings that are important in use around them. It is also of great practical value in engineering application. In this paper, the circular underground continuous wall supporting structure is taken as the research object, and the field monitoring data are analyzed. The common law of two key variables, the settlement of surrounding rock and soil mass and the displacement of wall body, are summarized, and the following results are obtained: 1) analyzing the field monitoring data. It has been obtained that the settlement at the monitoring point of 1 / 2 / 2 / 2 / 3 / 7 / 7 / 8 / 9 is linearly increased with the increase of excavation depth, and the increase rate is slightly different, and at the monitoring point of 4 / 5 / 5 / 6 condition, the variation of settlement is relatively small. In the range of excavation depth, the displacement of wall body increases linearly with the increase of excavation depth, and the reverse migration occurs below the excavation depth, and the maximum migration occurs at the 2/3 final excavation depth.) the cloud map and simulation data are analyzed. The position of the accumulated maximum value of surface settlement will move to the outside of the pit with the increase of the excavation depth. The settlement of the surrounding foundation pit is concentrated at the depth of the pit excavation 0.5-1.0 times from the edge of the foundation pit. With the increase of the excavation depth of the foundation pit layer by layer, The maximum displacement of the wall body moves down, and the curve of the displacement of the wall body is gradually similar to that of "S". It can also be obtained that the maximum displacement of the wall body appears in the area near the depth of 2/3 excavation to the bottom of the pit.) the monitoring data and simulation results are compared and analyzed. It is known that the finite element numerical simulation can effectively calculate and analyze the peripheral settlement and wall body displacement of circular underground continuous wall, predict the peripheral settlement and structural deformation of similar projects, reduce the project cost and improve the accuracy of construction monitoring.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU753

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