P波与SV波斜人射下岩体隧洞段地震应分

The existing coupling boundary simulation method has the problem that the displacement field of the model changes greatly, which affects the accuracy of the seismic response analysis results of a tunnel structures under oblique incidence of seismic waves, while the static-dynamic coupling effect is simulated by the artificial boundary transformation method. In this paper, an improved method of artificial boundary transformation using repeated static analysis was proposed, which makes the initial state of dynamic analysis of the finite element model consistent with the stress state and displacement field of static analysis, and the static-dynamic coupling analysis was realized. A numerical seismic analysis model under oblique incident P wave and SV wave was established using the ABAQUS software. The reliability of the model and the method was verified through an example. A series of nonlinear time-history analysis were carried out, and the influences of oblique incidence of P wave and SV wave on the seismic response of tunnel lining structure were compared and analyzed. Results show that the consistency of displacement displacement field of the tunnel can be ensured in the transformation of artificial boundary by the method. With the increment of the incident angle, the horizontal acceleration of the structure first increases and then decreases. While the vertical acceleration shows a decreasing trend under the action of P wave. Under the action of SV wave, both the horizontal acceleration and the vertical acceleration show an increasing trend. When the incident angle is larger than 20°, compared with P wave oblique incidence, the stress level of the arch shoulder and the arch foot under SV wave oblique incidence is higher; the damage degree of the tunnel structure under oblique incident SV wave is higher than that under oblique incident P wave.