试压工况下盾构隧道内输气管道应力分析

目前输气管道的应力分析主要针对普通埋设管道，对隧道内的输气管道（尤其是在试压工况下）的应力分析还比较少，一般情况下管道试压压力大于运行压力。因此，有必要分析试压工况下穿越输气管道的应力分布情况。为此，采用CAESARⅡ建立了试压工况下XX竖井盾构隧道穿越管道的应力分析模型，得到了穿越管道的应力分布情况，确定了应力关键点，校核了管道强度，通过实例分析发现管道应力的最大值在管道的弯管处。一次应力、二次应力和管道自重引起的应力对比分析结果表明，在试压压力较高的情况下，内压是产生管道应力的主要因素，而温度、管道自重对管道应力的影响很小。最后建议：在穿越管道的设计中应进行试压工况下的应力分析，以便找出应力集中点，采取相应的工程措施，保证穿越管道的安全运行。

Stress analysis of a gas pipeline through shield tunnels under pressure testing conditions

Stress analysis has rarely been conducted of gas pipelines through shield tunnels especially under pressure testing conditions. In general, the testing pressure is higher than the operating pressure so it is quite necessary for the operators to analyze the distribution of pressure on the gas pipeline through shield tunnels under such conditions. In view of this, the integraph CAESAR Ⅱ software was adopted to build a stress analysis model for a case study of XX silo shield tunnel. On this basis, the stress distribution was clearly shown; the stress key points were determined; the strength of the pipe was checked; and the maximum value of stress was found on the gas pipe elbows. Moreover, the primary stress, the secondary stress, and the self weight stress were comparatively analyzed to demonstrate that under higher testing pressure, the internal pressure is the main factor inducing the pipe stress while both temperature and the self weight of the pipe have little impact on the pipe stress. In the end, this paper suggests that stress analysis especially under pressure testing conditions should be done in the design of tunnel through pipelines; in this way, the stress concentration position will be so easily found out that corresponding engineering measures should be taken to ensure safe operation of tunnel through pipelines.