城市地下空间施工风险因素耦合效应研究

Coupling effect of risk factors in the construction of urban underground spaces

提出了风险因素耦合效应和风险因素耦合系数的定义,推导了耦合系数的计算方法,以广州南站为工程背景,对6组城市地下空间施工风险因素的耦合效应进行了研究,主要结论如下:(1)风险因素耦合效应指当多个风险因素同时存在时,由风险因素间的因果机制相关性导致的风险放大(或抑制)作用;(2)风险因素耦合效应与风险因素和风险事件间的条件概率密切相关,基于因果机制独立原理,可分离出耦合效应导致的条件概率增量,从而定义风险因素耦合系数;(3)风险因素耦合系数可通过响应面法结合贝叶斯网络进行计算;(4)城市地下空间施工风险因素耦合效应可分为"极强耦合"、"强耦合"、"中耦合"、"弱耦合"四级,相应的耦合系数取值范围建议为(0.5,1.0]、(0.25,0.5]、(0.1,0.25]和(0,0.1]。

Definitions of the risk factor coupling effect and the risk factor coupling coefficient are proposed,and a calculation method for the coupling coefficient is deduced.In the context of the Guangzhou South station,the coupling effects of six groups of urban underground space construction risk factors are studied.The main conclusions are as follows.(1)The coupling effect of the risk factors refers to the risk amplification(or suppression)effect caused by the correlation of the causal mechanisms between the risk factors when multiple risk factors exist at the same time.(2)The coupling effect of the risk factors is closely related to the conditional probability between the risk factors and the risk events.Based on the principle of causal independence,the conditional probability increment caused by the coupling effects can be separated to define the coupling coefficients of the risk factors.(3)The coupling coefficients of the risk factors can be calculated using the response surface methodology combined with a Bayesian belief network.(4)The coupling effects of the urban underground space construction risk factors can be divided into“extremely strong coupling,”“strong coupling,”“medium coupling,”and“weak coupling.”The recommended value ranges of the corresponding coupling coefficients are(0.5,1.0],(0.25,0.5],(0.1,0.25],and(0,0.1).