非均匀沉降下沿海天然气埋地管道安全运行分析

Analysis of Safe Operation of Buried Coastal Natural Gas Pipelines under Non-uniform Settlement

埋地天然气管道运行安全受地基非均匀沉降现象影响严重。为确保管道安全运行,通过对沿海地区埋地天然气管道进行应力监测,获取管道在地基非均匀沉降影响下的环向、轴向附加应力,并结合管道工作内压进行管道应力校核。基于ANSYS软件建立埋地天然气管道有限元模型,对比分析应力监测实际值与数值模拟结果,验证了应力监测数据的有效性和有限元模型的可行性。进一步通过有限元数值模拟探究管道内径、壁厚和埋土参数对管道应力的影响。数值模拟结果表明:在管道敷设阶段,通过减小管道内径、适当增加管道壁厚和选择较硬的埋土可以减小地基非均匀沉降对管道的影响。研究成果可为受地基非均匀沉降影响的埋地天然气管道运行安全提供参考。

The non-uniform settlement of foundations seriously influences operation safety of the buried natural gas pipeline.For purpose of ensuring the safe operation of the pipeline,the stress monitoring of the buried natural gas pipeline in coastal areas was carried out to obtain additional circumferential and axial stress of the pipeline influenced by non-uniform settlement of the foundation,and to check the pipeline stress in combination with working internal pressure of the pipeline.In addition,based on ANSYS software,the finite element model of the buried natural gas pipeline was established and the actual stress monitoring value and the numerical simulation results were contrastively analyzed to verify validity of the stress monitoring data and feasibility of the finite element model;meanwhile,influence of the pipeline’s inner diameter,wall thickness and buried soil parameters on the pipeline stress were further explored through finite element numerical simulation to show that,in the pipeline laying stage,reducing pipeline’s inner diameter,appropriately increasing its wall thickness and selecting harder buried soils can decrease the influence of the foundation’s non-uniform settlement on the pipeline.The research results provide the reference for safe operation of the buried natural gas pipelines affected by the foundation’s non-uniform settlement.