Dynamic interaction of the pipe-soil subject to underground blasting excavation vibration in an urban soil-rock stratum

Abstract

the When rock blasting excavation is carried out in urban soil strata, the vibration effect caused by blasting will cause the dynamic interaction between pipe and soil. If the dynamic interaction exceeds the bearing capacity of the pipe-soil system, it will cause serious damage. At present, there is no vibration velocity control standard for the buried pipeline under the influence of adjacent blasting excavation vibration, and there are few studies on the influence of internal operating pressure and pipe-soil interface on pipeline response. Therefore, we designed and implemented a full-scale blasting experiment near the buried gas pipeline, simulated the real-time process of rock blasting, and monitored the dynamic response data related to pipeline-soil interaction. The LS-DYNA dynamic finite element method (EFM) numerical calculation model was established to study the dynamic response characteristics of buried pipelines under blasting load and the influence of different working pressures. Research shows that the buried pipelines and soil layers are mainly vertical vibration, and the pipeline deformation is mainly axial tensile deformation. The dynamic peak effective stress (PES) of the pressure pipeline has three stages, which are initial stress, peak stress, and residual stress. The pressure has little influence on the peak particle vibration velocity (PPV) of the pipeline and has a great influence on the dynamic stress. The buried pipeline is mainly affected by the P wave of the blasting earthquake. Based on the interaction theory of pipe-soil interface under the action of blasting seismic P wave, the calculation model of effective stress peak (PES) of buried pipeline in soil was established, and the safety particle velocity peak (PPV) of the buried gas pipeline under different working pressure conditions was calculated.