A new approach based on the limit analysis upper bound theorem is proposed to assess the seismic stability of reinforced slopes of earth-rock dams. First, the dam slope is divided into horizontal slices with regarding the failure surface as an arbitrary surface. Under the assumption that the energy dissipation rate during failure due to reinforcement is caused by the effect of tensile forces, the internal work rate and the dissipation rate of each soil slice are then calculated. With the conditions of the energy-work balance equation, the maximum anti-seismic capability of dams can finally be optimized by intelligent algorithm. From the contrastive analysis, it is shown that the solutions presented here is in good agreement with those published previously in the literature. The results also indicate that if the quantity of horizontal slices is enough, the solutions obtained arc stable and the failure surfaces are well predicted. Based on the limit analysis, the solutions are proved to be very rigorous. Moreover, a more precise calculation of the pseu- do-static seismic loads could be obtained by the horizontal slice approach than the conventional vertical slice approach. Using the proposed method, the seismic stability of a typical reinforced rockfill dam with core wall is analyzed. The results show that the maximum anti-seismic capability of dams is increased by 19%-21% when the slope is reinforced. Meanwhile, the length of reinforcement has a great influence on the seismic stability of dams. Therefore, it is suggested that the optimum length of reinforcement should be investigated for engineering practice. For this numerical example, the optimum length of reinforcement is 30-40m.
Journal of Hydraulic Engineering