Abstract：A probabilistic fault tree is presented to model system reliability of rock wedge with multiple failure modes. The versatile 4-parameter b distribution is used to describe the basic random variables in the rock wedge stability model. The n-dimensional equivalent method is employed to perform the system reliability analysis of rock wedge. Reliability sensitivities in three different levels are discussed. An example is investigated to illustrate the proposed method. The results indicate that the failure probabilities of system for rock wedge using the proposed method are fully within the bounds of failure probability obtained from the Cornell bound method. The system reliability of rock wedge can be efficiently evaluated using the proposed method. In addition，the system reliability of rock wedge with correlated multiple failure modes can be intuitively represented by the probabilistic fault tree. The failure probability of system will be overestimated if the correlations between different failure modes associated with rock wedge are not taken into account. The negative correlation between cohesion and internal friction angle has a positive effect on the system reliability of rock wedge. Reliability sensitivity analysis has three levels，namely single limit state function level，single failure mode level and system reliability level. The importance of reliability sensitivity level should be realized due to the significant differences in sensitivity coefficient associated with the aforementioned three levels. Results from sensitivity analysis indicate that the water-pressure parameter and the geometry of rock wedge are significant random variables with higher sensitivity coefficients，which have a significant impact on the calculated failure probabilities of system. Accordingly，to improve the rock wedge stability effectively，a good drainage system for the slope should be designed；and a good structural characterization of discontinuities in the rock mass should be conducted. The proposed conclusions and approaches can form a basis for risk analysis of rock slopes.
李典庆，周创兵，胡冉. 基于n维等效方法的岩质边坡楔体稳定体系可靠度分析[J]. 岩石力学与工程学报, 2009, 28(07): 1415-1424.
LI Dianqing，ZHOU Chuangbing，HU Ran. SYSTEM RELIABILITY ANALYSIS OF ROCK SLOPE WEDGE STABILITY BASED ON N-DIMENSIONAL EQUIVALENT METHOD. , 2009, 28(07): 1415-1424.
