Deep excavations have many characteristics such as the complexity of construction conditions, uncertainties and the variety of risk. The risk variation of deep excavation and its risk concentrations are discussed in this paper by analyzing a deep foundation of the Shanghai area. Using the accumulative deformation and the change rate as the calculation index, monitoring data can be converted to the risk value and then the total risk level of the pit will be obtained. The two evaluation indicators are introduced: Absolute Concentration Index and the Herfindahl-Hirschman Index. The risk concentrations of the various factors are discussed in the excavation process. The results show that it can be more intuitive to get risk distribution state of the pit through the risk concentrations index. In order to improve the safety situation of the pit, it is needed to take some measures if we encountere the parts whose risk concentration level is higher.%深基坑工程具有施工条件复杂、不确定因素多以及风险动态变化等特点.以上海地区某深基坑为分析对象,讨论深基坑开挖过程中的风险变化和风险分布情况.考虑监测的累计变形和变化速率的影响,将监测数据转化为风险指标,进而得到基坑的总风险水平.引入绝对集中度和赫芬达尔指数两个评价指标,对基坑开挖过程中各因素的风险集中度进行分析.分析结果表明:采用风险集中度评价指标可以较为直观地得到深基坑各因素风险的分布情况,风险集中程度较大时应采取适当措施改善深基坑工程的安全状况.
展开▼
