大口径天然气管线穿越断层的管沟设计研究

为了保证埋地管线的抗震安全性，需要建立跨越断层埋地管线的力学分析模型、研究影响管道应变的因素并提出相应的抗震措施。目前，在埋地天然气管线抗震安全性研究方面，对管道应变影响最直接、最经济有效的管沟形状和尺寸这两个因素还没有予以研究。为此，应用有限元方法，首次建立了管沟尺寸及形状、管道埋深和回填土性质等因素对穿越断层埋地管线应变的影响分析模型，获得了不同管沟参数和回填土力学性质时的土弹簧参数，并应用ABAQUS软件进行了数值模拟分析，定量分析了管沟参数对管线应变的影响，最后根据基于应变的管道设计准则，提出了合理的管沟尺寸及形状，优化了穿越断层埋地管线的管沟设计，使管道应变降低了27.27%，有效提高了埋地管线的抗震安全性。

Trench design for buried cross-fault large-diameter gas pipelines

To ensure the earthquake resistance of buried pipelines, it is necessary to establish a mechanical model for the cross fault lines to study the factors affecting the pipeline strain, and then bring forward some relevant shock resistant proposals. At present, trench shape and size, the two factors having the most direct and economical influences on pipeline strain, have not been studied yet. Therefore, based on the finite element method, a strain analysis model for buried cross fault lines was established for the first time. It dealt with the influencing factors of pipeline strain, such as the trench size and shape, the depth of the buried pipes, back fill soil properties, etc. Thereby different trench parameters, mechanical properties of back fill soil and soil spring parameters were obtained. By means of the ABAQUS software, the influences of trench parameters on pipeline strain were quantitatively analyzed. Finally, according to the design rule of the strain based pipelines, the reasonable trench size and shape were proposed. The pipeline trench design was optimized and the pipeline strain was reduced by 27.22%, which has effectively boosted the earthquake resistance of buried pipelines.