Nonlinear response and reliability analysis of tunnels under strong earthquakes

Abstract

The damages of tunnels under earthquakes showed that soil-rock deposits around a tunnel have significant effects on its response to earthquake excitations, caused by the spatial variability and correlation of the soil properties, which may properly be modelled as a random field. This paper studied these effects through modelling the surrounding soil as a random field on the response of a tunnel and made some comparisons with the corresponding deterministic analysis. A twodimensional finite element model of the tunnel-soil system was examined, and the corresponding random field was simulated by the spectral representation method. The results revealed that the corners of the tunnel are the critical locations for the axial force and bending moment. The comparisons showed that the results of the deterministic analysis usually yield higher results than the corresponding random field results. The reliabilities of a tunnel for two limit-state functions were considered: one is defined as exceeding the design limit according to the Chinese design code, whereas the other is exceeding the ultimate strength of the reinforced concrete tunnel lining. The equivalent extreme events were formulated for the respective limit-state functions, from which the tunnel system reliability can be evaluated. The probability density evolution method was used to calculate the stochastic response and reliability of the tunnel under a strong earthquake.

Damage performance and failure analysis of reinforced concrete doubly curved shells under seismic excitations considering curvature and thickness variation

“…Earlier studies on shell structures have mainly focused on static analyses under equivalent static forces. Indeed, regarding studying the dynamic response, most of the previous studies concentrated on hemispherical domes or hyperbolic shells such as sports stadiums covering and cooling towers, respectively (Rihal, 2014; Kim and Sin, 2014; Yu et al, 2016; Yue and Ang, 2016; Zweifel and South, 2014). For the singly and doubly curvature shell roofs, the previous studies mainly focused on the linear dynamic response of these structures (Michiels and Adriaenssens, 2017; Ostovari Dailamani, 2010; Yazici, 2020), making it difficult to draw general conclusions, indicating a need for further systematic investigations of the nonlinear dynamic response.…”

Parallel Dynamic Analysis of a Large-Scale Water Conveyance Tunnel under Seismic Excitation Using ALE Finite-Element Method

“…On the FSI interface, the geometric compatibility and mechanical equilibrium conditions (Equations (4) and (5)) [17] should be satisfied, which cause the coupling of Equations (1)- (3).…”

“…The dynamic responses of a buried tunnel in general, and its seismic responses, in particular, are of much interest [1][2][3]. The water conveyance tunnel, as one kind of urban underground tunnel, guarantees domestic water for residents in metropolises, and is considered as the lifeline to a city.…”