基于马尔科夫链的风险演化模型探讨及其应用

Discussion on and Application of Risk Evolution Model Based on the Markov Chain

探讨了风险演化的定义,建立了基于马尔科夫链的风险演化模型,并给出了模型参数的确定方法。采用该模型对北京地铁17号线东大桥站的施工过程风险演化趋势进行了评估。评估结果表明,该工程施工风险具有阶段性特征,在竖井、风道、导洞、主拱以及各换乘通道和出入口等涉及较大土方开挖量的时期内风险较高;管线开裂、渗漏风险水平尤为突出,在整个施工过程中都不可忽视。模型评估结果符合工程实践经验认知,可以较为科学客观地反映风险的演化规律。

In the paper,the definition of risk evolution is discussed,a risk evolution model is established based on Markov chain,and the method for determining model parameters is given.This model is used to evaluate the risk evolution trend of the construction process of Dongdaqiao Station on Beijing Metro Line 17.The evaluation results show that the construction risk of the project has obvious phased dependency,and the risk is higher during the period involving a large amount of excavation,such as the construction phase of shaft,air duct,pilot tunnel,main arch,and transfer channels.Risk of pipeline cracks and leakage is particularly prominent and cannot be ignored during the entire construction process.The model evaluation results conform to the cognition of engineering practice experience,and can reflect the evolution law of risk more scientifically and objectively.