高压天然气管道爆裂冲击荷载下同沟敷设管道的动力响应及损伤机理

由于我国天然气管网和交通网络十分发达，并行管道与交通线交汇处采用的同沟敷设施工方案导致管道净间距受限，增加了发生连锁事故的风险。本课题针对高压天然气管道爆裂冲击荷载对同沟敷设并行管道的毁伤效应展开研究。深入分析管道爆裂冲击的爆源特性，建立可精确描述高压天然气管道爆裂能量转换过程的数学模型，计算土体中管道爆裂冲击波阵面状态参数。针对多种管体破坏模式对应的冲击荷载特征，以管道动力响应为切入点，构建冲击荷载下“管体-土介质”系统动力响应模型，建立系统拉格朗日动力方程，精确求解管体应力应变分布。结合理论推导、试验数据及仿真计算结果，在现行椭圆失效准则和应力失效准则基础上，研究得出管道在冲击荷载下的综合失效判据。成果将有助于深刻认识管道爆裂冲击荷载对同沟敷设并行管道的损伤效应及其作用机理，为高压天然气管道安全校核、风险评估提供技术支持，为相关规范的修订和完善提供理论支撑。

As China's gas pipeline network and transportation network are very developed, the construction scheme of laying in the same trench at the intersection of parallel pipeline and traffic line results in the limited net distance between pipelines, which increases the risk of chain accidents. In this research, the damage effect of high pressure gas pipelines explosion on parallel pipelines laid in the same trench will be studied. The characteristics of explosion source of pipeline physical explosion will be analyzed. The mathematical model which can accurately describe the energy conversion process of high-pressure gas pipeline explosion will be established. The state parameters of shock wave front of pipe explosion in soil will be calculated. According to the characteristics of impact load corresponding to different failure modes, the dynamic response of the pipeline is taken as the starting point. The dynamic response model of "pipeline-soil" system under impact load will be established, and the Lagrange dynamic equation of the system will be established to accurately solve the stress and strain distribution of the pipeline. Combined with the theoretical derivation, experimental data and simulation results, based on the current elliptical failure criterion and stress failure criterion, the comprehensive failure criterion of pipeline under impact load will be obtained. The research results are helpful to understand the damage effect and mechanism of the pipelines explosion on the parallel pipelines laid in the same trench, and provides technical support for safety check and accident prevention of high-pressure pipeline and theoretical support for revision and improvement of relevant specifications.