基于不确定性理论的基坑及周围环境风险评估及控制技术

发布时间：2018-04-28 00:07

本文选题：基坑工程 + 环境影响　；参考：《石家庄铁道大学》2013年硕士论文

【摘要】：随着经济的发展,城市的建设,大型地下空间的开发和利用成为必然。深大基坑数量越来越多,由于施工环境复杂,不确定性因素多,加上人们认识程度和方法的欠缺,引发了不少基坑事故,造成周围建筑物的倾倒或管线的破坏,影响了人们的正常生活和结构的正常使用。为此,如何尽可能的减小深基坑工程施工中的事故发生率以及灾害损失,己经成为了一个迫切需要解决的问题。风险分析理论为此提供一条可行的途径。本文采用不确定性理论对系统进行风险分析。首先,对不确定性理论进行了阐述,由于岩土体是一种不确定系统,基坑工程中存在着主观和客观上的不确定性,文中对基坑工程中不确定性的来源和具体不确定性因素进行分析。其次,建立基于D-S证据理论的基坑及周围环境风险评估体系,分别建立了基坑、建筑物、管线的风险评估指标,综合前人的研究成果,确定了基坑、建筑物、管线的变形控制标准,运用D-S证据理论将数值模拟结果和专家评估结论进行融合,可以得到基坑和周围环境系统的风险等级,并通过工程实例验证了方法的可行性。针对基坑工程中“水”这一影响工程安全性的关键因素,建立了基于模糊事故树方法的基坑防排水系统的风险评估体系,从止水、排水、降水三个方面建立了基坑工程防排水事故树,引入三角模糊数,计算系统模糊失效概率和基本事件的模糊重要度,通过工程实例验证了方法有效性,评估结论可为工程实践提供指导。最后,结合风险评估过程中基坑工程存在的风险及以往基坑事故的总结分析,从勘察、设计、施工三个方面对工程中存在的问题进行总结,提出改进措施,以控制和降低系统风险。
[Abstract]:With the development of economy, the construction of cities, the development and utilization of large underground space is inevitable. The number of deep foundation pit is more and more. Because of the complex construction environment, many uncertain factors, and the lack of people's knowledge and methods, many foundation pit accidents have been caused, and the dumping of surrounding buildings or the destruction of pipelines has affected people. Therefore, how to reduce the accident rate and disaster loss in the construction of deep foundation pit has become an urgent problem to be solved as far as possible. The theory of risk analysis provides a feasible way to solve this problem.
In this paper, the uncertainty theory is used to carry out the risk analysis of the system. First, the theory of uncertainty is expounded. Because rock and soil is an uncertain system, there is a subjective and objective uncertainty in the foundation pit engineering. The source of uncertainty in the foundation pit and the specific uncertainty factors are analyzed in this paper. Secondly, the establishment of the uncertainty of the foundation pit is established. Based on the risk assessment system of foundation pit and surrounding environment based on D-S evidence theory, the risk assessment indexes of foundation pit, building and pipeline are set up respectively. The deformation control standards of foundation pit, building and pipeline are determined by combining the previous research results, and the basis of D-S evidence theory is used to fuse the numerical simulation results and expert evaluation conclusions, and the basis can be obtained. The risk grade of the pit and surrounding environment system is tested and the feasibility of the method is verified through an engineering example. In view of the key factors affecting the safety of "water" in foundation pit engineering, a risk assessment system of foundation pit prevention and drainage system based on Fuzzy accident tree method is established, and the foundation pit workers are established from three aspects of water stop, drainage and precipitation. A triangular fuzzy number is introduced to calculate the fuzzy failure probability of the system and the fuzzy importance of the basic events. The effectiveness of the method is verified by an engineering example. The evaluation conclusion can provide guidance for the engineering practice. Finally, the risk and the previous foundation pit accidents in the process of risk assessment are summarized and analyzed. Review, design and construction three aspects of the existing problems in the project, and propose improvement measures to control and reduce system risk.

【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU753

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