PDEM-based seismic performance evaluation of circular tunnels under stochastic earthquake excitation

ABSTRACTTunnels are a vital component of urban infrastructure that must be robust against seismic hazards. Given the randomness of earthquake occurrence, the seismic response of tunnel structures mut be studied by stochastic analysis methods. To this end, this study proposes a probability density evolution method (PDEM)-based framework to investigate the seismic performance of a circular tunnel under stochastic earthquake excitation. First, a suite of nonstationary earthquake motions compatible with the seismic design code was derived using a stochastic earthquake model. Then, a series of nonlinear dynamic numerical simulations were conducted for a typical circular tunnel that considers the soil-structure interaction. Finally, using the tunnel inclination angle as the performance index, the probability density function of the structural response of the tunnel was solved using the PDEM to obtain the corresponding exceedance probabilities of the tunnel under various damage states. The results show that the PDEM-based framework can be applied to evaluate the seismic performance of circular tunnels and could serve as a reference on the seismic fragility of tunnels and underground structures.KEYWORDS: Tunnelprobability density evolution methodstochastic dynamic responseexceedance probability Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis research was supported by National Key Research and Development Program of China (grant number 2022YFC3800905), National Natural Science Foundation of China (Grants No. 52108381, 52238010, 52090082), Innovation Program of Shanghai Municipal Education Commission (grant number 2019-01-07-00-07-456 E00051), Shanghai Science and Technology Committee Program (Grants No. 22dz1201202, 21dz1200601, 20dz1201404, 22XD1430200), and Natural Science Foundation of Chongqing, China (No. CSTB2023NSCQ-MSX0808).