Abstract
The paper deals with the stability analysis of a water-saturated rock slope by means of the kinematic approach of limit analysis theory. Particular emphasis is first given to the effects of pore water pressure on the global stability of geotechnical structures. The rock strength properties being formulated in terms of effective stresses, it is shown how the effect of seepage flow may be accounted for such an analysis through driving body forces derived from the gradient of excess pore pressure distribution is shown. The latter is obtained as the solution to a hydraulic boundary value problem, and then incorporated as external loading in the subsequent stability analysis. The rock strength properties are modeled by a modified Hoek–Brown failure criterion, for which closed-form expressions of the support functions have been derived in a previous paper. The approach is then applied to investigate the stability of rock slopes. Computational results are given, providing ample evidence of the destablizing effects induced by the seepage forces. The influence of relevant geometrical, strength and loading parameters is also discussed.
Highlights
Assessment of the bearing capacity of rock structures, such as dam foundations, tunnels or rock slopes built in rock masses whose strength properties are described by traditional cohesivefrictional failure conditions, is a well-known classical problem in geotechnical engineering
In the second part of the paper, the approach is applied to investigate the stability of rock slopes in the presence of seepage forces. The distribution of these seepage forces are numerically evaluated through a finite element method and incorporated into the stability analysis based on the implementation of a rotational log-spiral failure mechanisms
The whole stability analysis presented in the sequel is based on the rigorous approach of considering the pore water pressure distribution derived from a finite element code
Summary
Assessment of the bearing capacity of rock structures, such as dam foundations, tunnels or rock slopes built in rock masses whose strength properties are described by traditional cohesivefrictional failure conditions, is a well-known classical problem in geotechnical engineering. Few studies were devoted to the assessment of bearing capacity of structures in rocks modeled by the latter strength criteria In this respect, one should quote the pioneer contributions of Baker and Frydman [9], Zhang and Chen [10], Drescher and Christopoulos [11] or Serrano and Olalla [12,13,14]. The present contribution is divided into two main sections The distribution of these seepage forces are numerically evaluated through a finite element method and incorporated into the stability analysis based on the implementation of a rotational log-spiral failure mechanisms
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