有软弱通道土坝变形及溃决的离心模型试验研究

Centrifuge Modeling on Deformation and Failure of Earth Dam with Weak Layer

土石坝稳定分析和溃坝机理研究具有重要的工程意义。离心模型试验通过离心力模拟重力,实现了模型试验应力与原型应力相等,是研究土石坝变形破坏过程的重要手段。围绕小型土坝在管涌工况下变形及溃决的特征和影响因素开展研究。在改进原有的溃坝离心模型试验设备的基础上,进行了一系列有软弱通道土坝溃决的离心模型试验。试验结果表明有软弱通道坝体的溃决过程为:首先管涌通道形成并逐渐贯通,然后下部坝体逐渐冲蚀,同时上部坝体塌陷或塌落,最后整个坝体溃决。管涌通道贯通是坝体发生溃决的重要影响因素,甚至可能是其发生的先决条件。

Stability analysis an d fa ilu re me chanism of ea r th dam a re of impor tant en g in ee rin g s ig n ific an c e. By using centrifugal force to simulate gravi ty, centrifuge model test has effectively solved th e problem of stress eq u a lity in model test. As a resul t , centrifuge model te s t h a s b e en an important means to investigate th e deformation an d failure process of earth dam . This a r t ic le focuses on th e deformation an d fa ilu re b ehavior of ea r th dams u n d e r p ip in g co n d i-tion. Centrifuge model te s ts on fa ilu re of ea r th dam with weak lay e r were co n d u c ted equipment. Test results show th a t th e proce ss of th e failure of e a r th dam with weak lay e r is as fo llow s： a pip in gchannel forms gradually a t firs t , an d in su b seq u en c e , th e lower dam is washed away gradua lly , an d u p p e r dam co l-lapses in the meantime , and th e whole dam b re ak s in th e e n d. The b reak th ro u g h of th e p ip in g c h a n n e l is an impor-tant influential factor , and even could b e th e p re req u is i te of dam fa i lu re.