考虑水力劈裂效应的重力坝坝踵裂缝稳定分析  

Analysis on crack stability at concrete gravity dam heel considering effect of hydraulic fracturing

作　　者：李宗利[1] 王锦丽[1] 刘霞[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《人民长江》2010年第8期86-88,共3页Yangtze River

基　　金：国家自然科学基金(50779057)

摘　　要：混凝土重力坝坝踵开裂是重力坝常见的现象,由于高坝缝内存在较高的扬压力,水压的劈裂作用有可能驱使裂缝进一步扩展,严重影响坝体的安全性。基于大型有限元分析软件,建立重力坝数值分析模型,人为在坝踵附近设置不同深度的裂缝,分析不同位置、不同裂缝深度、不同缝内水压分布作用下裂缝的稳定性,以分析水力劈裂效应。研究结果表明,坝踵附近裂缝多处于压剪复合断裂模式,但在缝内高水压作用下,有可能变为拉剪复合断裂,也极易失稳扩展;随着裂缝长度的增加,水力劈裂效应愈加显著。Cracking at concrete gravity dam heel is a common phenomenon.Due to hydraulic fracturing of uplift in the crack,the crack at dam heel would expand and influence the dam′s safety seriously.A numerical analysis model for gravity dam is built using finite element software.By the assumption of cracks at dam heel,the stability of dam heel crack is studied considering different crack location,crack depth and water pressure distribution type in cracks.The results show that the cracks at dam heel belong to compression-shear mixed fracturing type,however,it would be changed into tension-shear mixed fracturing type and easily expand due to high water pressure in crack;the hydraulic fracturing effect gets stronger with the increment of crack length and water pressure.

关 键 词：坝踵开裂 裂缝稳定性 水力劈裂 混凝土重力坝 

分 类 号：TV642.3[水利工程—水利水电工程]