材料分区方案对重力坝强震破坏过程的影响OA

To investigate the impact of material zoning on the dam failure process induced by earth-quakes,a case study was conducted on a concrete gravity dam located in southwestern China.Based on the original design,two retrofitting schemes were proposed:the internal reinforcement and the external thickening.Then,the nonlinear seismic response analysis was performed on the gravity dam,and the failure processes of the three schemes under strong earthquakes were examined by the overload method.The results indicate that failure zones for all three schemes occur at the dam heel,the upstream and downstream slope break,as well as the upper part of the downstream face.The failure patterns vary across the three schemes,both the original scheme and the external thickening scheme exhibit a penetrat-ing failure along the bottom of the low-strength concrete zone,while the internal reinforcement scheme shows a penetrating failure vertical to the slope at first,and then horizontal.Both retrofitting schemes can reduce the cumulative plastic dissipation energy within the dam body.In terms of ultimate seismic capaci-ty,the internal reinforcement scheme significantly outperforms the other two.Under the damping ratios of 0.10 and 0.05,the ultimate seismic capacity of the internal reinforcement scheme is 0.620g and 0.550g,respectively,which is notably higher than that of the original scheme(0.480g,0.410g)and the external thickening scheme(0.510g,0.450g).