基于应变设计方法在管道工程建设中的应用研究

Application of the Strain Design to the Pipeline Construction

埋地管道通过高震区和活动断裂带时将受到较大变形,影响管道的安全性。通过对基于应变设计方法、X80钢管力学性能和焊接工艺的研究,建立了有内压和无内压断层位移作用下管道的应变计算模型。综合考虑材料变形能力、环焊缝变形能力、焊缝缺陷影响、低周疲劳性能、管道内压等诸多因素确定管道极限应变和容许应变,提出了管道基于应变设计流程及相关要求。对西气东输二线通过强震区和活动断层区段的埋地管道进行了应变计算及校核,确立了管道工程抗震设计方法,制定了有效降低管道应变的优化敷设方案。

The buried pipeline passing through the meizoseismal area and active fault zone would induce large deformation,which affected the safety of the pipeline. The model for calculating the pipeline strain with internal pressure and without internal pressure was established by the researches on the strain design method,mechanical properties and welding process of X80 grade steel pipe. The ultimate strain and allowable strain were determined and design program and relative requirements based on the strain were proposed by considering the materials deformation abilities,girth weld distortion,welding defeat,low cycling fatigue properties,and internal pressure. The strain calculation and safety check for buried pipelines passing through the meizoseismal area and active fault zone of the second west-to-east gas pipeline project were conducted. The seismic design method of pipelines and optimized laying method for effectively decreasing the strain were also put forward.