地下储库材料参数概率分布估计及体系可靠度分析

Estimation of Material Parameters Probability Distribution and Analysis of System Reliability for Underground Deposit

在岩土工程领域中,由于大量不确定信息的存在,人们对工程安全问题,要充分考虑随机特性的影响。在估计盐岩地下油气储库系统失效概率时,首先需要确定各相关材料参数的概率分布特征。地下油气储库结构复杂,通过极大似然法对岩土材料随机变量分布情况进行参数估计,采用贝叶斯公式分析其验后分布密度,确定符合工程实际的参数概率分布。建立数值计算模型,分析结构体系主要失效模式,以莫尔-库仑准则为失效准则;结合工程实际将结构划分为串并联混合体系,在点可靠度计算基础上分析盐岩地下油气储库体系可靠度。

For the safety of geotechnical structure,influence of randomicity should be considered because of kinds of exsiting uncertainties.Before the system failure probability of salt rock oil and gas underground deposit is estimated,parameters＇ probability distribution of correlative materials must be determined.By reason of the complexity of undergound deposit,taking account of reality of project,distribution of random variables of geotchnical materials are deternined by maximum likelihood estimation mothod,distribution density functions are anaylsed by Bayes formula.Then,primary failure modes are considered,numerial computation model is eatablished,and Mohr-Coulomb criterion is determined as failure criterion.At last,the structure is simulated as a Series-Parallel combined system,the system reliability is calculated based on the computation of reliabilty of some key points.