中文摘要：

城市地下管线是城市的重要基础设施和组成部分。近年来,各类地下管线事故时而发生,给人们的生产和生活,以及城市的运行带来了严重的损失。科学认识各类可能引起管线事故的风险因素,及时采取有效措施是保障管线的安全平稳运行的重要手段。本文首先分析了当前我国城市地下管线运行的安全形势和地下管线事故类型,在此基础上从地下管线系统自身、自然环境和外部人为环境三方面出发构建了城市地下管线风险因素框架,并对威胁地下管线安全运行的几类主要风险因素进行了深入的分析。

英文摘要：

The underground pipeline system is an important part of city′s infrastructure.In recent years,various kinds of underground pipeline accidents have happened frequently,which brought serious losses to the people′s work and life,as well as threatening city′s safety management.Understanding of various risk factors that may cause accidents and taking effective measures of them timely are important to keep safety operation of the pipelines.Firstly,this paper analyzes the current safety situations of urban underground pipelines and the types of accidents occurred.The framework of risk factors from the underground pipeline system itself is then proposed with consideration of the natural environment and external anthropogenic environment.At last,the main risk factors are analyzed in depth.