基于动态监测与事故树分析的超大深基坑风险分析方法研究

Research on risk analysis method of super-large deep foundation pit based on dynamic monitoring and fault tree analysis

为对城市特大交通枢纽超大深基坑工程进行动态风险等级定量分析,提出风险事故树与基坑动态监测数据相结合的超大深基坑工程风险分析方法。列举基坑工程典型的各类风险源,绘制风险事故树并分析其基本事件结构重要度,将风险影响程度高的监测项目作为风险动态评价指标,同时考虑监测项目的动态评价因素和静态评价因素,将主因素突出法和综合评价分析法相结合。方法应用于北京城市副中心站特大交通枢纽超大深基坑工程项目中。研究结果表明:可有效避免获取事故树底事件发生概率的困难和单一使用综合评价分析法对基坑风险评价的失真影响,在实际工程中能够得到合理的基坑风险等级,具有较好的实用性和可操作性。研究结果可为超大深基坑工程风险分析提供参考。

In order to quantitatively analyze the dynamic risk level of super-large deep foundation pit projects in urban mega transportation hubs,a risk analysis method for super-large deep foundation pit projects combining the risk fault tree and the dynamic monitoring data of foundation pit was proposed.The typical types of risk sources of foundation pit projects were listed,then the risk fault tree was drawn,and the structure important degree of its basic events was analyzed.The monitoring items with a high degree of risk impact were taken as the risk dynamic evaluation indexes,and considering the dynamic and static evaluation factors of the monitoring items,the method of highlighting the main factors was combined with the and combines with the method of comprehensive evaluation and analysis.The method is applied to the project of super-large deep foundation pit of mega transport hub at Beijing Urban Vice Centre Station.The research results show that the method effectively avoids the difficulty of obtaining the probability of occurrence of events at the bottom of the accident tree and the distorting influence of the single use of the comprehensive evaluation and analysis method on the evaluation of the foundation pit risk,and is able to obtain a reasonable risk level of the foundation pit in the actual project,which is of good practicability and operability.The research results can provide reference for the risk analysis of oversized deep foundation pit project.