胶结土坝漫顶溃坝模型试验研究

Experimental study on overtopping and dam break model of cemented soil dam

通过开展大尺度胶结土坝溃坝模型试验,对胶结土坝在洪水漫顶作用下的流速分布、坝体侵蚀的变化过程进行了分析,以验证胶结土坝漫顶不溃的可能性。试验结果表明:模型填筑胶结土28 d无侧限抗压强度达到4 MPa以上;胶结土坝在最大坝顶水头为55 cm、下游坡比1∶2、最大流速达5.6 m/s条件下,漫顶冲刷44 h未发生溃决破坏;漫顶冲刷后下游坝坡最大侵蚀深度为10 cm,平均侵蚀深度仅为1.07 cm;胶结土坝可有效防止洪水漫顶冲刷引发的溃决破坏。

Through the large-scale model test of cemented earth dam,the velocity distribution and the dam erosion process of cemented earth dam under the flood overtopping were analyzed to verify the feasibility of non-failure overtopping of cemented earth dam.The test results show that the unconfined compressive strength of cemented soil within the model is more than 4 MPa after 28 days.When the maximum water head at the crest of cemented earth dam is 55 cm,the downstream slope ratio is 1∶2 and the maximum velocity reaches 5.6 m/s,there is no collapse failure after the overtopping scouring for 44 h.After the overtopping scouring,the maximum erosion depth of downstream dam slope is 10 cm and the average erosion depth is only 1.07 cm,thus the cemented earth dam can effectively prevent the collapse caused by the overtopping scouring of flood.