高面板堆石坝分期分区填筑高差对坝体变形影响研究

Research on the Influence of Filling Height Difference on the Dam Deformation of the High Face Rockfill Dam

高面板堆石坝需采用分期分区的填筑方法,填筑高差的选取会对坝体变形产生一定影响。运用FLAC3D对阿尔塔什面板堆石坝进行三维数值模拟,分析其在反抬高下游填筑形式下上下游填筑体高差为5、10、15、20、25、30 m时坝体的应力变形情况。结果表明:填筑高差越大坝体应力变形越大,也对面板的受力状态更为不利;填筑高差达到30 m时,坝体最大竖直沉降达84.8 cm,下游侧水平位移12.9 cm,最大主应力2.23 MPa,且下游特征点变形倾度达1.02%,超过临界变形倾度,可能发生剪切破坏。综合考虑,高面板堆石坝在设计填筑方案时,应十分注重上下游填筑高差的选择,建议高差小于30 m。

The filling method of high face rockfill dam should be divided in stages. The selection of filling height difference will have certain influence on the deformation of the dam body. FLAC3D is used to carry out three-dimensional numerical simulation of Altash face rockfill dam, and the stress deformation of the dam body is analyzed when the height difference between the upstream and downstream fill body is 5, 10, 15, 20, 25 and 30 m under the form of reverse elevation downstream fill. The results show that the greater the height difference is, the greater the stress deformation of the dam body is, and the worse the stress state of the face plate is. When the height difference is 30 m, the maximum vertical settlement of the dam body is 84.8 cm, the horizontal displacement of the downstream side is 12.9 cm, the maximum principal stress is 2.23 MPa, and the deformation inclination of the downstream characteristic point is 1.02%, exceeding the critical deformation inclination, shear failure may occur. Overall consideration, when designing the filling scheme of high face rockfill dam, great attention should be paid to the selection of the height difference between upstream and downstream filling, and it is recommended that the height difference be less than 30 m.