深基坑土钉墙与桩锚联合支护方案设计及变形分析

发布时间：2018-03-14 07:56

本文选题：深基坑　切入点：FLAC3D　出处：《中国地质大学(北京)》2015年硕士论文　论文类型：学位论文

【摘要】：深基坑工程是涉及工程地质条件、气候条件、周围环境、技术水平和管理水平等多因素的复杂的工程问题,具有复杂性,综合性,高风险性等特点。桩锚支护以其经济,安全的特点被广泛应用于深基坑支护设计中。由于基坑超挖,边坡过载,管线泄漏,预警滞后等造成的工程事故屡见不鲜,造成了严重的经济和财产损失。工程实践证明,单纯依赖理论设计和简单的现场监测已经很难满足复杂周边环境、不良地质条件等深基坑安全施工。越来越多的学者开始呼吁加强基坑开挖监测分析,建立完善的信息化施工管理体系以指导施工,达到安全、经济、高效施工的效果。本文结合北京某深基坑工程,在分析其开挖深度、工程地质条件、周边环境等因素的基础上对支护结构进行了设计,同时制定了支护桩体深层水平位移、桩顶沉降和锚杆轴力等参数的监测方案,并根据规范要求制定了监测预警值。通过对监测数据的整理和分析,研究了支护结构内力、变形特征及基坑边坡稳定性,总结了桩锚支护体系在粉砂地层基坑支护中的应用效果。借助基于有限差分法的FLAC3D数值模拟软件进行基坑开挖模拟分析。根据工程地质勘察数据建立地层模型和设置合理边界条件,并采用Cable单元、Pile单元和Beam单元等模拟支护结构。用Null单元模拟基坑分部开挖,并记录每层开挖时最大不平衡力和各单元内力及变形情况。最后通过对比模拟数据和监测成果,验证基坑稳定性,并为以后类似工程提供设计参考。
[Abstract]:Deep foundation pit engineering is a complex engineering problem involving many factors, such as engineering geological condition, climate condition, surrounding environment, technical level and management level. It has the characteristics of complexity, comprehensiveness, high risk and so on. The characteristics of safety are widely used in deep foundation pit support design. Engineering accidents caused by over-excavation of foundation pit, slope overload, pipeline leakage and early warning lag have caused serious economic and property losses. Relying solely on theoretical design and simple on-site monitoring, it has been difficult to meet the complex surrounding environment, poor geological conditions and other deep foundation pit safe construction. More and more scholars began to call for strengthening the foundation pit excavation monitoring analysis. A perfect information construction management system is established to guide the construction to achieve the effect of safe, economical and efficient construction. This paper analyzes the excavation depth and engineering geological conditions of a deep foundation pit project in Beijing. Based on the surrounding environment and other factors, the supporting structure is designed, and the monitoring scheme of the deep horizontal displacement of the supporting pile, the settlement of the pile top and the axial force of the bolt are established. According to the requirements of the code, the monitoring and early warning value is established. Through the analysis of the monitoring data, the internal force, deformation characteristics and slope stability of the foundation pit are studied. The application effect of pile anchor support system in silt foundation pit support is summarized. The foundation pit excavation simulation analysis is carried out with the help of FLAC3D numerical simulation software based on finite difference method. The stratum model is established according to the engineering geological survey data. Setting reasonable boundary conditions, Cable element and Beam element are used to simulate the excavation of foundation pit, and the maximum unbalanced force and the internal force and deformation of each unit are recorded by Null element. Finally, the simulation data and monitoring results are compared. Verify the stability of foundation pit and provide design reference for similar projects in the future.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU753

【参考文献】