Random Seismic Response and Dynamic Fuzzy Reliability Analysis of Bedding Rock Slopes Based on Pseudoexcitation Method

摘要

Seismic ground motion is a dynamic random process, and it has obvious random uncertainty. The traditional reliability analysis of bedding rock slopes under earthquake excitation is usually based on pseudostatic method and dynamic time-history analysis method, both of which ignore the random nature of earthquake excitation. Furthermore, the existing power spectral density (PSD) method for seismic response can consider the random nature of seismic activity using finite element software, but the process of calculation is time-consuming and laborious, and the calculated response results are difficult to use directly in seismic reliability analyses of slopes. This paper presents a fast algorithm for the random seismic response of bedding rock slopes using the pseudoexcitation method. Based on the calculated results, a calculation method for a dynamic fuzzy degree of reliability of bedding rock slopes under random earthquake excitation is presented using the first-excursion failure criterion, taking into account uncertainties in the strength parameters and structural limit states. A comparison with the existing method is performed to verify the proposed fast algorithm. Then, the effectiveness of this proposed calculation method is studied by comparison with a general method. A further sensitivity analysis is presented to reveal the influences of seismic ground motion parameters and fuzzy uncertainties (in strength parameters and structural limit state) on the reliability of bedding rock slopes.