摘要
针对高坝泄洪消能防护安全问题,通过模型试验,对护坡板块背/迎水面的动水压强进行同步测量,从时域、频域角度研究护坡板块的动水压强特性,对比不同止水破坏型式和不同排水速率对护坡板块的水动力特性的影响,揭示护坡结构失稳机理。结果表明:(1)在排水失效情况下,盲缝一(仅上侧止水破坏)为止水破坏最不利情况,缝隙内的水不容易排出,护坡板块背水面脉动压强最小、时均压强最大,产生较大的时均压强差,背/迎水面测点的相关性最弱会产生较大脉动压强差;时均压强占主导地位,产生较大的背/迎水面总压差,致使板块最容易失稳。(2)对于抽排板块,当排水速率一定时,板块下部测点的时均压强差大于上部测点;随着板块排水速率的增加,背水面时均压强和背/迎水面压强差都逐渐减小,且减小趋势变大。对于水位剧烈波动区域,抽排板块相对于排水失效板块更利于护坡结构的稳定。研究成果可为水垫塘边坡防护结构的设计优化提供理论依据。
Aiming at the safety of protection structure for flood discharge and energy dissipation of high dams, the hydrodynamic pressure on the back and front surfaces of the slope lining slab was synchronously measured through model tests, and the hydrodynamic characteristics of the slope lining slab were compared from the perspective of time domain and frequency domain. The influence of different waterstop failure modes and different drainage rates on the hydrodynamic characteristics of the slope lining slab was compared to analyze the instability mechanism of the slope protection structure. The results show that(1) Drainage failure: The most adverse condition is the upper waterstop damaged. Because water in the gap is difficult to discharge, the fluctuating pressure on the back surface of the slope lining slab is the smallest and the mean pressure is the largest, resulting in a large mean pressure difference. The correlation between test points on the back and front surfaces is the weakest, resulting in large fluctuating pressure difference. The mean pressure is dominant, resulting in a large total pressure difference between the back and front surfaces, which makes the slab prone to instability.(2) Drainage slab: the mean pressure difference at the lower test points of the slab is larger than that at the upper test points with the same drainage rate. With the increase of drainage rates, both the mean pressure on the back surface and the pressure differences gradually decrease, and the decreasing trend becomes larger. Slabs equipped with drainpipes and pumps are more conducive to the stability of slope protective structure than slabs without drainpipes in the area of severe water level fluctuation. The research results of this paper can provide a theoretical basis for the design optimization of the slope protective structure of plunge pools.
作者
马斌
臧少慧
李会平
MA Bin;ZANG Shaohui;LI Huiping(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300350,China;School of Civil Engineering,Tianjin University,Tianjin 300350,China)
出处
《水利水电技术（中英文）》
北大核心
2021年第5期109-120,共12页
Water Resources and Hydropower Engineering
基金
国家重点研发计划资助项目(2016YFC0401707)
国家自然科学基金项目(51779167
51809194)。
关键词
水垫塘
护坡板块
动水压强
止水破坏
排水速率
模型试验
渗流
plunge pool
slope lining slab
hydrodynamic pressure
waterstop failure
drainage rate
model test
seepage
stability
