溶洞对支护桩稳定性影响研究
发布时间：2018-10-19 09:52
【摘要】：岩溶地区的桩需要考虑溶洞对桩稳定性的影响。溶洞对垂直承载桩的稳定性影响研究已开展过较多的研究工作,而溶洞对水平承载桩的稳定性影响研究在国内外还没有开展过。本文选择周边有溶洞存在的基坑支护桩为研究对象,运用数值分析的方法研究溶洞对支护桩的稳定性影响。按照溶洞和支护桩的相对位置,将岩溶地区支护桩与溶洞的受力分析模型分成三种,第一种模型为溶洞位于支护桩的下方；第二种模型为溶洞位于支护桩的主动区；第三种模型为溶洞位于支护桩的被动区。通过数值计算,分析在溶洞的大小形态、溶洞与桩的相对位置、桩的嵌固端深度、桩长、桩径、上覆土层厚度及基坑开挖深度等因素影响下,溶洞对支护桩稳定性的影响。每种计算模型又按上覆土层厚度的大小分成5个亚类,每个亚类的力学分析参数取值按正交试验方法进行设计,通过建立溶洞影响稳定性判据求出溶洞到支护桩的临界安全距离。通过计算发现,土层厚度较薄时溶洞对支护桩没有影响,当土层厚度较厚时溶洞对支护桩有影响,并对有影响的部分进行了多元线性回归,求出了临界安全距离和各影响因素之间的数学表达式,并用工程实例进行了验证。研究成果为解决岩溶地区支护桩的稳定性分析的问题并编制有关规范的相关条文提供了基础性技术依据。
[Abstract]:The influence of karst cave on pile stability should be considered in karst area. The influence of cavern on the stability of vertical bearing pile has been studied, but the influence of cave on the stability of horizontal bearing pile has not been carried out at home and abroad. In this paper, the influence of karst cave on the stability of supporting pile is studied by numerical analysis. According to the relative position of karst cave and supporting pile, the stress analysis model of supporting pile and karst cave in karst area is divided into three kinds: the first model is that the cave is located under the supporting pile, the second model is located in the active zone of supporting pile. The third model is that the cave is located in the passive zone of the supporting pile. Through numerical calculation, the influence of karst cave on the stability of supporting pile is analyzed under the influence of the size and shape of the cave, the relative position of the cave to the pile, the depth of the embedded end, the length of the pile, the diameter of the pile, the thickness of the overlying soil layer and the excavation depth of the foundation pit. Each model is divided into five subclasses according to the thickness of the overlying soil, and the mechanical analysis parameters of each subclass are designed by orthogonal test method. The critical safety distance from the cavern to the supporting pile is obtained by establishing the stability criterion of the cavern. Through calculation, it is found that the cavern has no influence on the supporting pile when the soil thickness is thinner, and the cavern has influence on the supporting pile when the soil layer is thicker, and carries on the multivariate linear regression to the affected part. The mathematical expressions between the critical safety distance and the influencing factors are obtained and verified by an engineering example. The research results provide a basic technical basis for solving the stability analysis of supporting piles in karst areas and compiling relevant provisions of relevant codes.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1
本文编号：2280781
[Abstract]:The influence of karst cave on pile stability should be considered in karst area. The influence of cavern on the stability of vertical bearing pile has been studied, but the influence of cave on the stability of horizontal bearing pile has not been carried out at home and abroad. In this paper, the influence of karst cave on the stability of supporting pile is studied by numerical analysis. According to the relative position of karst cave and supporting pile, the stress analysis model of supporting pile and karst cave in karst area is divided into three kinds: the first model is that the cave is located under the supporting pile, the second model is located in the active zone of supporting pile. The third model is that the cave is located in the passive zone of the supporting pile. Through numerical calculation, the influence of karst cave on the stability of supporting pile is analyzed under the influence of the size and shape of the cave, the relative position of the cave to the pile, the depth of the embedded end, the length of the pile, the diameter of the pile, the thickness of the overlying soil layer and the excavation depth of the foundation pit. Each model is divided into five subclasses according to the thickness of the overlying soil, and the mechanical analysis parameters of each subclass are designed by orthogonal test method. The critical safety distance from the cavern to the supporting pile is obtained by establishing the stability criterion of the cavern. Through calculation, it is found that the cavern has no influence on the supporting pile when the soil thickness is thinner, and the cavern has influence on the supporting pile when the soil layer is thicker, and carries on the multivariate linear regression to the affected part. The mathematical expressions between the critical safety distance and the influencing factors are obtained and verified by an engineering example. The research results provide a basic technical basis for solving the stability analysis of supporting piles in karst areas and compiling relevant provisions of relevant codes.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1
【参考文献】
相关期刊论文 前1条
1 李大通,罗雁;中国碳酸盐岩分布面积测量[J];中国岩溶;1983年02期
，本文编号：2280781
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