基于多相耦合的含缺陷埋地管道外爆破坏影响因素研究

含缺陷埋地管道受到外爆载荷作用时缺陷处可能会发生贯穿,并进一步引起管道大面积破坏。考虑含缺陷管道与管内流体的流固耦合作用、土体与管道间的接触作用,建立了土体-含缺陷管道-流体的外爆多相耦合模型。基于损伤积累的破坏准则,计算管道缺陷处在外爆载荷作用下的损伤积累比率,分析了管道破坏的损伤积累过程。通过对比不同缺陷深度、形状,探讨缺陷结构对管道破坏的影响;并通过改变炸药量、爆心距,探讨外爆载荷对管道破坏的影响。结果表明:缺陷损伤在壁厚方向外侧大于内侧,二者之间的差值随时间推移而减小,最终二者损伤达到极限使管道破坏。损伤值随缺陷深度的增加而增大,圆形缺陷要比菱形和椭圆形对爆炸波抵抗能力强80%;管道损伤速度随炸药量增加而增大,1 m爆心距比3 m的损伤值高出2140%,管道破坏对爆心距的敏感度高于炸药量。研究成果可为工程爆破施工和预防含缺陷管道的外爆破坏提供参考。

Study on Influencing Factors of Buried Pipeline with Defect under External Explosion Destruction Based on Multiphase Coupling

For the buried pipeline with defects,the defect may break through thickness under the action of external blasting load,and further cause extensive damage to the pipeline.Considering the fluid-solid coupling between the pipe with defect and the fluid inside the pipe and the contact between the soil and the pipe,a multiphase coupling model of soil-defect-containing pipe-the fluid was established.Based on the law of cumulative damage,the damage accumulation rate of pipeline defect under the external explosion load was calculated,and the damage accumulation process of the pipeline was analyzed.By comparing the depth and shape of different defects,the influence of damage of the defect-containing structure on the pipeline was discussed.And by changing the explosive volume and the explosive distance,the influence of the explosion load on the pipeline damage was discussed.The results show that the defect damage outside is larger than that inside in the thickness direction,and the difference between them decreases with time,finally the two damages reach the limit and the pipe is destroyed.The damage value increases with the increase of defect depth.The resistance of circular defect to explosion waves is 80%higher than the diamond and elliptical defects.The damage speed increases with the increase of explosive volume.The damage value at 1 m explosion distance is 2140%higher than at 3 m,and pipe destruction is more sensitive to explosion distance than explosive volume.The research results can provide reference for engineering blasting construction and prevention of external explosion damage of pipelines with defects.