基于水槽试验的泥石流拦挡坝泄水涵洞调控性能  

Regulation Performance of Drainage Culvert of Debris Flow Dam Based on Flume Test

作　　者：董耀刚[1] 刘兴荣[1] 冯乐涛[1] 王喜红 张丽娟 DONG Yao-gang;LIU Xing-rong;FENG Le-tao;WANG Xi-hong;ZHANG Li-juan(Geological Hazards Prevention Institute, Gansu Academy of Sciences, Lanzhou 730000, China)

机构地区：[1]甘肃省科学院地质自然灾害防治研究所,兰州730000

出　　处：《科学技术与工程》2022年第5期1794-1802,共9页Science Technology and Engineering

基　　金：甘肃省2021年度重点人才项目(2021RCXM066);甘肃省科技计划(20YF3FA006);甘肃省科学院院列科技计划(2021JK-07);甘肃科学院科技产业化项目(CY08);甘肃省科学院青年基金(2018QN-11)。

摘　　要：拦挡坝体上布设泄水涵洞对泥石流破坏力的调控能力问题长期未得到强有力的证实。为此,采用室内水槽试验模拟泥石流对3种类型拦挡坝(Ⅰ型、Ⅱ型和Ⅲ型)的作用过程,从中获取拦挡坝坝后泥位、振动加速度、体积含水率和孔隙水压力等力学参数的变化数据,对比分析泥石流拦挡坝泄水涵洞的调控性能。结果表明:拦挡坝布设泄水涵洞会促使泥石流快速完成水石分离,减轻泥位的剧烈变化;加设拦挡坝后,泥石流的振动加速度会大幅减弱,且3种类型拦挡坝的坝后振动加速度数据比较接近,说明拦挡坝是否布设泄水涵洞对其遭受泥石流冲击力的大小几乎无影响,拦挡坝布设泄水涵洞并不会明显降低坝体安全性;Ⅰ型拦挡坝对体积含水率影响大,Ⅱ型、Ⅲ型拦挡坝体积含水率瞬间增大后又快速回落,说明布设泄水涵洞对减小坝前雍水的效果明显;预留泄水涵洞后,可以明显减轻下游坝体的孔隙水压力破坏,达到保护下游坝体的目的。以上试验现象说明,拦挡坝增设泄水涵洞可显著降低泥石流的破坏作用。The regulation ability of discharge culvert on the retaining dam to the destructive force of debris flow has not been strongly confirmed for a long time. Therefore, the indoor flume test was used to simulate the action process of debris flow on three types of retaining dams(type Ⅰ, type Ⅱ and type Ⅲ), from which the change data of mechanical parameters such as mud level, vibration acceleration, volumetric moisture content and pore water pressure behind the retaining dam were obtained, and the regulation performance of the discharge culvert of the debris flow retaining dam was compared and analyzed. The results show that the layout of discharge culvert in retaining dam promotes the rapid separation of water and stone and reduce the drastic change of mud level. After adding a retaining dam, the vibration acceleration of debris flow is greatly reduced, and the vibration acceleration data behind the dam of the three types of retaining dams are relatively close, indicating that whether the retaining dam is equipped with a discharge culvert has little impact on the impact force of debris flow, and the layout of a discharge culvert in the retaining dam will not significantly reduce the safety of the dam. Type Ⅰ retaining dam has a great impact on the volumetric water content, and the volumetric water content of type Ⅱ and type Ⅲ retaining dams increases instantaneously and then decreases rapidly, indicating that the layout of discharge culvert has an obvious effect on reducing the Yongshui in front of the dam. After reserving the discharge culvert, the pore water pressure damage of the downstream dam body can be significantly reduced to achieve the purpose of protecting the downstream dam body. The above experimental phenomena show that the addition of discharge culvert in retaining dam can significantly reduce the destructive effect of debris flow.

关 键 词：拦挡坝 泄水涵洞 水槽试验 力学参数 调控性能 

分 类 号：P642.23[天文地球—工程地质学]