Dynamic disturbance scattering such as blasting generates dynamic stress concentration which is an important factor resulting in instability and damage in underground structures. In this paper, a theoretical model of a deeply buried pipeline under plane P-wave incidence is developed based on the wave function expansion method. Fourier transforms and Duhamel integrals were introduced to solve the transient response around a deeply buried circular aqueduct, and the effect of wavelength on the transient response was analyzed. Considering that the ground stress is a non-negligible factor for the destabilization of deep structures, a numerical model was established with the help of LS-DYNA finite element software to analyze the dynamic response mechanism of deeply buried pipelines under the action of the initial stress. The results of the study show that the compressive stress concentration generated by short-wave incidence is greater, and the tensile stress concentration due to long-wave incidence is greater, and the tensile stress concentration is very easy to occur along the direction of incidence. The larger the lateral pressure coefficient, the more pronounced is the suppression of the dynamic response in the presence of initial stresses. In addition, the pipeline and the surrounding rock mass under the initial stress state will experience more drastic fluctuations in the stress state when subjected to dynamic loading. These research phenomena reveal that the dynamic response mechanism of underground pipelines and the impact of the in-situ stress environment, which can be used for the seismic optimization design of deep underground structures.

dynamic response  /  dynamic stress concentration factor (DSCF)  /  numerical simulation  /  initial stress  /  lateral pressure coefficient