黏土斜墙式自溃坝溃决水槽试验研究

Experimental study on clay inclined wall self-breaking flume

为研究心墙坡度、心墙相对位置等因素对黏土斜墙式自溃坝溃决过程的影响,探究溃决过程中斜心墙的破坏过程,本研究采用室内水槽物理模型试验开展了6组不同工况的物理模型试验。试验结果表明,黏土斜墙式自溃坝溃决过程可分为5个阶段,以3、4阶段中的堆积体底角淘刷后退、心墙临空面暴露、斜心墙断裂等现象为斜墙自溃坝溃决典型现象;溃决峰值流量随心墙坡度增加而增加,峰值到来时间随心墙坡度增加而缩短;心墙位置偏向下游峰值流量相对较小,峰值到来时间相对较短;心墙坡度对自溃坝外壳横向、纵向侵蚀速率影响较小,心墙坡度主要通过影响心墙临空面高度的形成速率从而影响其溃决过程,心墙临空面高度的形成速率随斜墙坡度增加而增加。在采用自溃式溢洪道用以提高水库防洪标准时,本文试验结果可作为参考通过改变心墙构造进一步提高水库防洪能力。

In order to study the influence of core wall slope,relative position and other factors on the collapse process of clay-inclined wall self-break dam,and explore the failure process of the inclined wall during the collapse process,this study carried out six groups of physical model tests under different conditions by using indoor flume physical model tests.The test results show that the process of clay-inclined wall self-break dam failure can be divided into five stages.In the third and fourth stages,the bottom corner of the deposit body is washed back,the free face of the core wall is exposed,and the inclined wall is fractured.The peak burst flow increases with the increase of wall slope,and the peak arrival time decreases with the increase of wall slope.The peak flow of the core wall is relatively small and the peak arrival time is relatively short.The slope of the core wall has little influence on the lateral and longitudinal erosion rate of the self-breaking dam shell.The slope of the core wall affects the failure process mainly by influencing the formation rate of the height of the free surface of the core wall,and the formation rate of the height of the free surface of the core wall increases with the increase of the slope of the inclined wall.When the self-collapsing spillway is used to improve the flood control standard of reservoir,the test results of this paper can be used as a reference to further improve the flood control capacity of reservoir by changing the core wall structure.