徐州深基坑双排桩支护结构应用研究

发布时间：2018-01-27 15:42

本文关键词： 基坑支护双排桩受力变形基坑监测数值模拟　出处：《中国矿业大学》2014年硕士论文　论文类型：学位论文

【摘要】：双排桩支护结构由于抗弯刚度大、施工灵活等特点，逐渐在城市基坑支护中得到广泛应用。目前，对三角形布置的双排桩支护结构的设计方法尚不明确，故本文以徐州云龙观邸基坑工程为背景，在前人研究成果的基础上，，采用理论计算、实测分析与三维数值模拟方法，对三角形布置的双排桩进行了较为系统的研究，主要成果与结论如下：（1）总结了前人对双排桩支护结构的计算方法及土压力作用理论，并研究了双排桩在不同排距及桩间距下的土压力变化规律，确定土压力分布形式，通过结构力学理论求出桩体水平位移，对双排桩进行理论计算分析，并验证数值模拟的合理性。（2）建立了双排桩三维计算模型，深入分析了不同排距、桩间距、嵌固深度、桩径对双排桩支护结构受力变形的影响及不同排距、桩间距下桩间土的土拱效应，明确了双排桩设计中参数的合理取值范围；并对不同土体c、φ值下的双排桩受力变形进行了分析，得出了c、φ值的不利范围；此外，对带撑双排桩及加锚杆的双排桩进行了分析，结果表明，在带撑或加锚杆情况下，双排桩的受力形式更加合理，弯矩及变形得到了良好的控制。（3）总结了双排桩的设计及施工要点，并通过现场监测数据，对桩体水平位移、冠梁位移、道路及建筑物沉降进行了分析，得出了桩体及土体随基坑开挖的变化规律以及对周边环境的影响程度，支护效果证明了双排桩支护结构在控制基坑变形方面的合理性。（4）以实际工程为背景，建立了数值分析模型，将实测数据与计算结果进行对比，变形趋势及数量级基本一致，证明了数值模拟的合理性；同时，提出了基坑的优化设计方案，将内支撑方案改为双排桩支护形式，模拟结果表明双排桩在位移控制方面比较理想，虽然位移控制能力小于内支撑方案，但从施工、工期等角度考虑，采用双排桩方案更为有利。
[Abstract]:The double-row pile supporting structure has been widely used in the city foundation pit support because of its large bending stiffness and flexible construction. At present, the design method of the triangular double-row pile supporting structure is not clear. Therefore, based on the foundation pit engineering of Yunlong Mansion in Xuzhou, based on the previous research results, this paper adopts theoretical calculation, measured analysis and three-dimensional numerical simulation method. A systematic study of the triangular double-row piles is carried out. The main results and conclusions are as follows: 1) the paper summarizes the calculation method of double-row pile supporting structure and the theory of earth pressure, and studies the variation law of earth pressure of double-row pile under different row spacing and pile spacing, and determines the distribution form of earth pressure. The horizontal displacement of the pile is calculated by the structural mechanics theory, and the theoretical calculation and analysis of the double-row pile are carried out, and the rationality of the numerical simulation is verified. (2) the three-dimensional calculation model of double-row piles is established, and the influence of different row spacing, pile spacing, embedded depth, pile diameter on the deformation of double-row pile supporting structure and different row spacing are analyzed. The soil arch effect of soil between piles under pile spacing, and the reasonable value range of the parameters in the design of double-row piles are determined. The deformation of double-row piles under different soil C and 蠁 values is analyzed, and the disadvantage range of c and 蠁 values is obtained. In addition, the analysis of double-row piles with bracing and bolting is carried out. The results show that the force forms of double-row piles are more reasonable and the bending moment and deformation are well controlled under the condition of braced or bolted piles. The main points of design and construction of double-row piles are summarized, and the horizontal displacement of pile, displacement of crown and beam, settlement of roads and buildings are analyzed through field monitoring data. The variation law of pile and soil with excavation and the degree of influence on surrounding environment are obtained. The supporting effect proves the rationality of double-row pile supporting structure in controlling foundation pit deformation. (4) based on the actual engineering background, the numerical analysis model is established, and the measured data are compared with the calculated results. The deformation trend and order of magnitude are basically consistent, which proves the rationality of the numerical simulation. At the same time, the optimization design scheme of foundation pit is put forward, which changes the internal support scheme into the double-row pile support form. The simulation results show that the displacement control of double-row piles is ideal, although the displacement control ability is smaller than that of the internal support scheme. However, it is more advantageous to adopt double row pile scheme from the point of view of construction and time limit.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1

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