Assessment of stability for reliability theory in consideration of change of shear resistance by depth

Slope stability is one of the most common problems in construction design. The application of application software often follows a pattern, using only fixed input parameters and resulting in a factor of safety according to the parameters themselves. This calculation model is only correct during the time when the shear resistance parameter (c, j) of the ground does not change. Therefore, this method is no longer appropriate once utilizing the structure because of leading to slope instability and causing landslides that damage to the slope after a period of exploitation. The experimental studies have shown that the shear resistance parameter (c, j) of the soil ground changes randomly with depth. As a result, current mechanical computational models are no longer valid. This paper proposes a new model to analyze stability based on reliability theory with the change of shear resistance parameters by depth. Firstly, by using Karhunen – Loeve series, the result of slope stability coefficient of the proposed model is smaller than those without consideration of shear resistance variation (c, j) by depth. Then, by using Monte - Carlo simulations (n=1000) combined with Karhunen – Loeve series, the results obtained are different from those which only consider the static problem, so the problem of random quantities and the probability of failure increase significantly.