爆炸载荷对埋地输气管道的动力响应和极限载荷分析

Analysis on Dynamic Response and Extreme Loads of Buried Gas Pipeline Under Blast Loading

定量分析临近管道爆破对埋地输气管道产生的动力响应有助于合理制定输气管道的安全保护措施。利用LS-DYNA 3D有限元程序,根据准静定理论计算爆腔半径,在爆腔内壁施加压力时程,建立了爆腔-岩土介质-输气管道动力相互作用模型,基于多种工况下的数值模拟分析,探讨了埋地输气管道动态响应过程中管道质点速度和动应力峰值分别和装药量、爆心距的关系,以两倍弹性斜率准则确定管道在特定工况下的极限载荷,进一步建立了装药量和施工安全距离的经验关系式,此式可以作为输气管道在近距离爆破施工条件下的破坏判据。该模型为埋地输气管道在第三方荷载作用下的风险评估提供了一个计算平台,对埋地输气管道的设计、施工和完整性管理具有一定的参考价值。

The quantitative analysis of the dynamic response of buried pipeline under blast loading in sight of the pipeline will redound to constitute reasonabe gas pipeline safety precautions.In this paper,calculating radius of explosion cavity on quasi-static theory and applying equivalent pressure time-histories inside explosive cavity in LS-DYNA 3D program,The reciprocity mode among explosion cavity,soil and buried gas pipeline is established.The relationship between dynamical maximal responses of buried gas pipeline and the mass of detonator or the distance from blasting center including velocity and dynamical stress is discussed,limit load is confirmed based on the two elastic slope criteria in the specific cases,and the experiential relationship between the mass of detonator and the safe distance is discussed,this relationship can be used as the damage criterion of pipeline engineering under blast.The method of numerical simulation in this paper provided a calculation platform for the risk evaluation of buried gas pipelines during third-party interference and the conclusion in this paper may provide some references for the risk evaluation,design and construction of buried gas pipeline.