地震荷载作用下重力坝坝踵裂缝内水压分布研究  

Research on internal pressure distributions in dam heel crack of gravity dam under earthquake loads

作　　者：何迪[1] 李宗利[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》2011年第9期72-75,共4页Yangtze River

基　　金：国家自然科学基金项目(50779057)

摘　　要：在地震荷载作用下,重力坝内水下裂缝突然闭合时会产生较大的附加水压力,从而可能引起裂缝失稳,对大坝抗震不利。基于大型有限元软件建立数值分析模型,人为在坝踵设置初始张开宽度为0.001 m的楔形裂缝,以分析在地震作用下不同长度、不同方向的裂缝内部的最大水压分布规律。其中,库水及缝内水体采用势流体单元,库水与坝体、坝基间采用流固单元。研究结果表明,随着裂缝长度的增长,裂缝内最大水压不断增加,最大可达到初始静水压的8.13倍;而随着裂缝角度的增大,裂缝内最大水压先增大后减小;裂缝长度越长,裂缝内最大水压随着角度变化越明显。Large additional water pressure can be caused by the fast closing of the cracks in gravity dams under earthquake loads,which may induce crack instability that is unfavorable to dam safety.A numerical analysis model for gravity dam is established using finite element software.On the assumption that the cracks is a wedge-shaped fracture with 0.001m initial width at dam heel,internal pressure distributions laws are studied considering different crack lengths and angles.Reservoir water and water in crack are simulated by potential flow element,and fluid-solid element is adopted to simulate coupling effect between water and dam body,dam foundation.The results show that the maximum water-pressure increases with increasing in length,which can reach 8.13 times of initial hydrostatic pressure.However,with the increase of crack angle,the maximum water-pressure increases first and then decreases.Meanwhile,the longer the cracks are,the more obvious the maximum water-pressure changes with angle.

关 键 词：裂缝 地震荷载 最大水压力 坝踵裂缝 重力坝 

分 类 号：TV642.3[水利工程—水利水电工程]