爆破P波作用下直埋压力管道安全振速研究

基于爆破产生的P波入射作用下均匀内压薄壁管道的受力特点，采用拟静力分析和叠加原理建立压力管道爆破地震波作用下的应力解析计算模型；基于压力管道材料屈服特性及Tresca屈服理论，建立爆破P波作用下压力管道的振动安全判据计算模型，并结合爆炸影响的直埋压力薄壁管道工程案例进行解析验算。研究结果表明:爆破荷载施加前管道仅受均匀内压，具有初始轴向和切向应力，爆破发生后，管道同时受到内压和爆破地震波P波动荷载作用；管?土界面入射波临界角较小，管道峰值应力随入射角度增大减小，垂直入射时主要发生拉伸破坏，全反射时主要为切向破坏；压力管道安全控制振速随入射角的增大而增大，随运行内压的增大而减小，实际工程中根据管道内压实际情况，选择较小的值作为安全控制值。 

Safe vibration velocity of directly buried pressure pipeline under blasting P wave

With the continuous development of urban underground space in China, safety problems between urban underground pipelines and underground engineering construction that are in active service are constantly emerging. As an important way of excavating engineering rock and soil mass, blasting has a particularly prominent impact on pressure pipelines due to its harmful seismic effect. It is of great significance to study the vibration damage effect of the pressure pipeline under the excavation blasting earthquake to guide the safety production of the adjacent pipeline blasting construction and the safety design of the pressure pipeline under the influence of adverse factors such as blasting vibration. Based on the above research requirements, the stress characteristics of a thin-walled pipe with uniform internal pressure under an incident P-wave caused by blasting are first analyzed. The stress analytical calculation model under the seismic wave of pressure pipeline blasting is then established by quasi-static analysis and superposition principle. Based on the yield characteristics of pressure pipeline materials and the Tresca yield theory, a safety criterion calculation model for the vibration velocity of pressure pipeline under P-wave blasting is established. Combined with two engineering cases of a directly buried pressure thin-walled pipeline under explosion, the calculation model is verified. Results show that before the application of blasting load, the pipeline is only subjected to uniform internal pressure with initial axial and tangential stresses. After blasting, the pipeline is subjected to both internal pressure and blasting seismic P-wave load. Results reveal that the peak stress of the pipeline decreases with the increase of the incident angle. Moreover, the tensile failure mainly occurs at normal incidence, and the tangential failure mainly occurs at the total reflection. The vibration velocity of the safety control of the pressure pipeline increases with the increase of the incident angle. In the actual project, according to the actual situation of the internal pressure of the pipeline, the smaller value is selected as the safety control value.