大型地下结构泄排水减压抗浮控制研究

发布时间：2018-11-13 18:39

【摘要】：城市地下空间的综合开发利用已成为世界城市发展的共同选择,大型和超大型地下结构如雨后春笋般不断涌现,但是随之而来的是大型地下结构抗浮安全问题。而传统被动式抗浮方法工艺复杂、投资大,并且存在众多技术难题,例如地下结构的耐久性和抗疲劳等方面的技术问题。因此,寻找新的绿色的抗浮方法已成为大型地下空间开发与利用亟待解决的重要课题。本文针对地下结构新的抗浮方法—泄排水抗浮方法,对其抗浮机理、抗浮理论分析计算体系、工程风险与质量控制等关键技术问题进行了系统研究。首先,本文以深圳某大型地下停车库建设为研究背景,通过从工期、全寿命周期费用等七个方面系统全面的比较常见抗浮方法的特点,以及基于泄排水抗浮的机理深入分析探讨,总结出泄排水抗浮是一种节材、节能的绿色抗浮工艺和方法,并指出了该方法一般适用于弱透水层场地。接着,本文通过泄排水减压机理研究和结合工程特点,确定了泄排水抗浮的主要设计参数为基础底部孔隙水压力水头等四个参数；并从现代系统控制理论的角度总结出了泄排水抗浮动态控制的原理和控制系统的构成,其控制原理和过程主要是依据实时全面的监测数据信息,基于有限元渗流分析与计算结果,通过调节水平横管的标高,从而动态适时进行地下结构抗浮安全和周边环境保护控制。然后,本文基于饱和土与非饱和土的地下水渗流理论,建立了泄排水抗浮渗流计算有限元模型。并通过多种工况的渗流分析计算,优化确定了该工程的抗浮设计参数控制范围和设计值。并重点对抗浮设计中的两个关键问题(系统水头损失和结构运营期对周边环境的影响)进行了深入探讨。此外,本文基于工程风险管理基本理论,提出了泄排水抗浮风险管理流程框架。通过有限元计算计算分析,识别和确定了泄排水抗浮失效风险指标。并基于所建立的泄排水抗浮系统失效的故障树建模分析,找出了导致泄排水抗浮失效的所有可能的故障模式和发生的概率,并根据重要度分析结果制定出了抗浮风险的控制对策。最后,本文分析了抗浮系统倒滤层的质量控制问题。确定了倒滤层的构成型式以及关键控制参数设计计算,总结和提出了倒滤层的施工流程和施工控制要点。并通过对地下结构施工阶段和运营阶段八种监测数据的综合,讨论了泄排水抗浮控制的效果,得出如下结论：泄排水抗浮方法对周边环境的影响非常小,该方法经济合理、技术可行。本文对地下结构泄排水抗浮方法的研究成果具有一定的理论意义和工程应用价值,可以为类似大型地下工程建设提供参考。
[Abstract]:The comprehensive development and utilization of urban underground space has become a common choice for the development of cities in the world. Large and super-large underground structures are springing up, but the safety of anti-floating of large-scale underground structures follows. However, the traditional passive anti-floating method has many technical problems, such as durability and fatigue resistance of underground structures. Therefore, finding a new green anti-floating method has become an important subject to be solved urgently in the development and utilization of large underground space. In this paper, a new anti-floating method for underground structures, drainage and anti-floating method, is studied systematically, such as anti-floating mechanism, anti-floating theoretical analysis and calculation system, engineering risk and quality control, and so on. First of all, this paper takes the construction of a large underground parking garage in Shenzhen as the research background, and compares the characteristics of common anti-floating methods systematically and comprehensively from seven aspects, such as time limit, life cycle cost, etc. Based on the thorough analysis and discussion on the mechanism of anti-floating of drainage, it is concluded that the anti-floatation of drain drainage is a kind of green anti-floating technology and method of saving material and saving energy, and it is pointed out that this method is generally suitable for the site of weak permeable layer. Then, through the study of decompression mechanism of drainage and combined with the characteristics of the project, the main design parameters of anti-floating of drainage are determined as four parameters: the pore water pressure head at the bottom of the foundation. From the point of view of modern system control theory, the paper summarizes the principle of anti-floating dynamic control of drains and the constitution of control system. The control principle and process are mainly based on real-time and comprehensive monitoring data information. Based on the results of finite element seepage analysis and calculation, by adjusting the elevation of horizontal pipe, the anti-floating safety and environmental protection control of underground structure are carried out dynamically and timely. Then, based on the groundwater seepage theory of saturated soil and unsaturated soil, the finite element model of anti-floating seepage is established. The control range and design value of the anti-floating design parameters of the project are optimized through seepage analysis and calculation under various working conditions. Two key problems in anti-floating design (system head loss and the influence of structure operation period on the surrounding environment) are discussed in detail. In addition, based on the basic theory of engineering risk management, this paper puts forward the framework of risk management of drainage and anti-floating. Through finite element calculation and analysis, the risk index of anti-floating failure of drainage is identified and determined. Based on the fault tree modeling and analysis of the failure of drainage anti-floating system, all the possible failure modes and the probability of occurrence are found out. According to the results of importance analysis, the control countermeasures of anti-floating risk are worked out. Finally, the quality control of anti-floating system is analyzed. The structure of the filter layer and the design and calculation of the key control parameters are determined. The construction process and the key points of construction control of the filter layer are summarized and put forward. By synthesizing eight kinds of monitoring data of underground structure in construction stage and operation stage, the effect of anti-floating control of drainage is discussed. The conclusion is as follows: the influence of anti-floating method of drainage on the surrounding environment is very small, and the method is economical and reasonable. The technology is feasible. This paper has certain theoretical significance and engineering application value for the research results of underground structure drainage and anti-floating method, and can provide reference for similar large-scale underground engineering construction.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU94

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