【摘要】 为探明施工过程中影响钢管桩围堰事故发生率的主要因素，降低桥梁基础工程的事故发生率，建立FBN与MIDAS模型，对围堰工程进行事前安全风险研究。首先参照条例规范与4M1E原则将主要因素统筹为人、机、料、法、环五大方面，构建起具有普适性的的风险评估指标体系，其中含有5个一级指标和18个二级指标。其次根据因素间的逻辑关系构建贝叶斯网络模型，基于模糊数理论确定根节点的先验概率，后利用Leaky Noisy-OR Gate模型计算出非根节点的条件概率，通过NETICA软件得到因素耦合效应以及主要影响因素，最后依据实际案例建立MIDAS有限元模型进行定量化分析。结果表明，主要影响因素有水流压力、土体稳定性、支护体系稳定性、焊接质量以及安全防护设备配备程度。更多还原

【Abstract】 To find out the main factors that affect the accident rate of steel pipe pile cofferdam during construction and reduce the accident rate of bridge foundation engineering,FBN and MIDAS models are established to study the safety risk of cofferdam in advance. First of all,with reference to the regulations and 4M1E principles,the main factors are divided into five aspects:human,machine,material,method and environment,and a universal risk assessment index system is constructed,which contains 5 first-level indicators and 18 second-level indicators. Secondly,the Bayesian network model is constructed according to the logical relationship between factors,the a priori probability of root node is determined based on fuzzy number theory,and then the conditional probability of non-root node is calculated by Leaky Noisy-OR Gate model. Factor coupling effects and main influencing factors are obtained through NETICA analysis. Finally,according to the actual case,MIDAS finite element model is established for quantitative analysis. The results show that the main influencing factors are flow pressure,soil stability,support system stability,welding quality and the degree of safety protection equipment.更多还原