Influence of oblique incidence of P-waves on seismic response of prefabricated utility tunnels considering joints

The dynamic performance of prefabricated utility tunnels under seismic excitation is a topic that deserves careful study, especially when considering the oblique incidence of P-waves. Instead of ignoring the effect of axial forces on the stiffness of joints in prefabricated utility tunnels and assuming the stiffness to be constant values, this paper carefully investigated the nonlinear mechanical behavior of joints in all directions by numerical and theoretical methods at first. After the data processing work, the nonlinear behavior was introduced into the 3D real-site numerical model, and the seismic responses of prefabricated utility tunnels with different incident angles of P-waves were simulated. The results showed that the axial forces play an important role in the nonlinear mechanical behavior of joints, the forces and deformations of joints in different directions reached their peaks with different incident angles. Based on the study, it is recommended that the effects of the non-linearity of joint stiffness and the incident direction of earthquake waves should be taken into consideration during the seismic design of prefabricated utility tunnels.