基于时间效应基坑变形特性分析
发布时间：2018-08-09 19:52
【摘要】：随着城市化进程的不断发展,在软土地区建设过程中对环境保护的要求越来越高,深基坑的开挖不仅需要考虑自身的安全和稳定,还需要顾忌对周围建筑物的影响。目前关于软土地区基坑稳定性控制已经从强度控制发展到变形控制,并也逐渐将时间因素考虑在内。为了更好的研究这方面的问题,引入蠕变理论,运用合适的弹粘塑性本构模型对深基坑的土体变形进行研究,以求得到加入时间因素后土体变形特征。主要进行了以下几方面的工作：(1)概括总结基坑变形中时间效应的研究现状,总结各种研究途径和成果,深入分析各类工程问题中时间效应的影响程度,为此方面的研究指明方向并提供依据。(2)在基坑的地质概况、设计方案及该地区基坑工程的特点进行调查分析的基础上,对实际监测资料进行整理,同时基于时间效应对结果进行分析和评价。(3)基于正交试验参数反演将第一步开挖监测的最大下沉值作为试验指标,针对Kelvin粘滞系数、Kelvin切变模量两个反演因素进行正交设计,通过对试验结果进行分析,确定一组接近试验指标的土体力学参数,并对其进行调整优化,确定一组误差相对较小的参数作为反演成果。(4)将围护桩最大侧向变形容许值作为安全控制指标,应用有限差分法FLAC3D数值模拟软件对实际工程进行数值模拟,并与现场实测数据进行对比分析。在定性分析的基础上定量分析深基坑施工过程中正常开挖及时支撑和超挖这两种情况下,基坑结构随时间的变化规律从而预测深基坑的安全放置时间。
[Abstract]:With the development of urbanization, the requirement of environmental protection is becoming higher and higher in the process of soft soil construction. The excavation of deep foundation pit not only needs to consider its own safety and stability, but also needs to worry about the influence of surrounding buildings. At present, stability control of foundation pit in soft soil area has developed from strength control to deformation control, and time factor has been gradually taken into account. In order to study this problem better, the creep theory is introduced, and the soil deformation of deep foundation pit is studied by using the suitable elasto-viscoplastic constitutive model, so as to obtain the deformation characteristics of soil after adding time factor. The main works are as follows: (1) summarize the research status of time effect in foundation pit deformation, sum up various research approaches and achievements, and analyze the influence degree of time effect in various engineering problems. The research in this area shows the direction and provides the basis. (2) on the basis of the geological survey, design scheme and the characteristics of the foundation pit engineering in this area, the actual monitoring data are sorted out. At the same time, the results are analyzed and evaluated based on the time effect. (3) based on the orthogonal test parameter inversion, the maximum subsidence value of the first step excavation monitoring is taken as the test index, and the orthogonal design is carried out for the two inversion factors of the Kelvin viscosity coefficient and the Kelvin shear modulus. Through the analysis of the test results, a group of soil mechanics parameters close to the test index are determined, and the parameters are adjusted and optimized. A set of parameters with relatively small error is determined as the inversion result. (4) taking the allowable maximum lateral deformation of the retaining pile as the safety control index, the numerical simulation software of finite difference method (FLAC3D) is used to simulate the actual engineering. And the field measured data are compared and analyzed. On the basis of qualitative analysis, the variation law of foundation pit structure with time during normal excavation and over-excavation is quantitatively analyzed, and the safe placing time of deep foundation pit is predicted.
【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】：2014
【分类号】：TU473
本文编号：2175139
[Abstract]:With the development of urbanization, the requirement of environmental protection is becoming higher and higher in the process of soft soil construction. The excavation of deep foundation pit not only needs to consider its own safety and stability, but also needs to worry about the influence of surrounding buildings. At present, stability control of foundation pit in soft soil area has developed from strength control to deformation control, and time factor has been gradually taken into account. In order to study this problem better, the creep theory is introduced, and the soil deformation of deep foundation pit is studied by using the suitable elasto-viscoplastic constitutive model, so as to obtain the deformation characteristics of soil after adding time factor. The main works are as follows: (1) summarize the research status of time effect in foundation pit deformation, sum up various research approaches and achievements, and analyze the influence degree of time effect in various engineering problems. The research in this area shows the direction and provides the basis. (2) on the basis of the geological survey, design scheme and the characteristics of the foundation pit engineering in this area, the actual monitoring data are sorted out. At the same time, the results are analyzed and evaluated based on the time effect. (3) based on the orthogonal test parameter inversion, the maximum subsidence value of the first step excavation monitoring is taken as the test index, and the orthogonal design is carried out for the two inversion factors of the Kelvin viscosity coefficient and the Kelvin shear modulus. Through the analysis of the test results, a group of soil mechanics parameters close to the test index are determined, and the parameters are adjusted and optimized. A set of parameters with relatively small error is determined as the inversion result. (4) taking the allowable maximum lateral deformation of the retaining pile as the safety control index, the numerical simulation software of finite difference method (FLAC3D) is used to simulate the actual engineering. And the field measured data are compared and analyzed. On the basis of qualitative analysis, the variation law of foundation pit structure with time during normal excavation and over-excavation is quantitatively analyzed, and the safe placing time of deep foundation pit is predicted.
【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】：2014
【分类号】：TU473
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