Study on Slope Stability by a Dual Index System
Weiwei Luo, Rui Huang, Jin Xin Gong · 2006
The convention approach to assessing slope stability is through the calculation of safety factor. However, shortcoming of this approach is that uncertainties in slope system are not explicitly reflected in safety factor. Reliability theory can consider uncertainties in slope system. However, reliability theory is complicated and short of experience. Therefore it is necessity to establish dual index system of slope stability coupling safety factor and reliability theory. Most likely safety factor (mean-value safety factor) was calculated with average value of parameters, and reliability of slope was calculated with variability of safety factors. It was assumed that safety factors obey normal distribution or lognormal distribution, a series of most likely safety factors and failure probabilities of slope Pf were calculated with different coefficient of variation. Most likely safety factors were multiplied by corresponding reliability (R=1–Pf), and most likely safety factors were reduced. From limit state of reduced safety factors, critical failure probabilities corressponding different most likely safety factors were calculated. According to different most likely safety factors and their failure probabilities, a divisional chart of slope stability was drawn, and then a dual index system of slope stability coupling safety factor and reliability theory was established.