堤坝裂缝集中渗流冲蚀起动判别指标对比分析  

A comparative analysis of initiation indices for concentrated flow-induced crack erosion in dam and embankment

作　　者：李维朝[1] 尚静石[1] 李少朋 唐斌 LI Weichao;SHANG Jingshi;LI Shaopeng;TANG Bin(State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Beijing Engineering Corporation Limited,Powerchina,Beijing 100024,China;China Water Investment Co.,Ltd,Beijing 100053,China)

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038 [2]中国电建集团北京勘测设计研究院有限公司,北京100024 [3]中国水务投资有限公司,北京100053

出　　处：《中国水利水电科学研究院学报》2021年第5期469-475,共7页Journal of China Institute of Water Resources and Hydropower Research

基　　金：国家重点研发计划(2018YFC1505004);流域水循环模拟与调控国家重点试验室项目(SKL2020ZY09)。

摘　　要：管涌和裂缝集中渗流冲蚀均是堤坝中最常见的渗透破坏形式。但与管涌研究相比,国内外关于裂缝集中渗流冲蚀的研究成果相对较少,并且冲蚀起动的判别指标也不统一。鉴于此,本文参照泥沙动力学、桥基水力冲刷、水土流失等相近学科中已相对成熟的水力冲蚀机理,在裂缝集中渗流作用力分析的基础上,对水力坡降、流速和水力剪应力3个最常用的裂缝冲蚀判别指标进行了对比分析。分析表明,水力坡降和流速两个判别指标虽然可以直接测量,但临界值会受到裂缝宽度的影响;水力剪应力作为裂缝冲蚀判别指标,虽然难以直接量测,需间接计算得出,但该判别指标不仅避免了裂缝宽度对试验结果的影响,还可以将堤坝裂缝中水力冲蚀的起动与裂缝发展过程紧密结合、连续描述。通过对水力坡降、流速和水力剪应力3个常用判别指标的对比分析,本文建议今后统一使用水力剪应力作为裂缝冲蚀起动的判别指标。Piping and crack erosion are the popular phenomena of seepage-induced failure. But research on crack erosion is relative scarce comparing to piping,and different initiation indices for crack erosion are often used. Referred to the research on hydraulic erosion by other subjects, such as sediment dynamics,scour of bridge foundation, and soil erosion, and based on the hydraulic analysis of concentrated flow in the crack, comparative analysis of initiation indices is conducted for concentrated flow-induced crack erosion in dam and embankment. It shows that hydraulic gradient and velocity can be measured directly,and hydraulic shear stress is difficult to measure. But as a crack erosion index,hydraulic stresses can be calculated without being influenced by the width of the crack,and this index can be used to express the initiation and development of crack erosion. Through comparative analysis, hydraulic stress is recommended to be used as an initiation index for concentrated flow-induced crack erosion in dam and embankment.

关 键 词：集中渗流 冲蚀 水力剪应力 裂缝 堤坝 

分 类 号：TV698.2[水利工程—水利水电工程]