剪胀性对边坡潜在滑动面的影响  

The influences of the dilatancy character on the potential sliding surface of soil slopes

作　　者：康亚明[1] 刘长武[1] 贾延[2] 方延强[1] 

机构地区：[1]四川大学水利水电学院,四川成都610065 [2]西北第二民族学院基础部,宁夏银川750021

出　　处：《中国矿业》2008年第4期89-91,94,共4页China Mining Magazine

基　　金：国家自然基金资助项目(50568003);国家自然基金资助项目(50574064);教育部科学技术研究重点项目(205174)

摘　　要：有限元分析岩土边坡对剪胀性的影响,常采用两种极端的方法：过大地考虑了材料的剪胀性和完全不考虑材料的剪胀性,而这往往与工程实际情况不符。在平面应变条件下,通过剪胀角的变化来考虑剪胀性对土坡潜在滑动面的影响。计算结果表明,剪胀性对其有比较明显的影响：随着剪胀角的减小,塑性区有从坡顶向坡角贯通的趋势。因此,在工程实际中,对密实性砂土和超固结粘土,由于在剪切过程中会表现出较强的剪胀性,有限元分析时建议用关联法则;对于松散质土（欠固结土）,由于其具有剪缩性,建议用非关联的法则;对于一般砂土和粘土（正常固结土）,应对剪胀角进行折减,建议剪胀角ψ取内摩擦角φ的1/3-1/2。The analysises of rock and soil slopes often adopt two extreme methods： overstating the material dilatancy character or ignoring the material dilatancy character, which do not agree with the engineering. The dilatancy character has influences on potential sliding surface of slope. In ANSYS software, this influences were considered through the variety of dilatancy angle. The potential sliding surface was simulated in plane strain condition with ANSYS in this article. The results show that the dilatancyangle has obvious influences on the potential sliding surface. The plastic zone has a trend on running through from the top to the bottom of the slope with the reducation of dilatancyangle. So the associated flow rules should be used to analyze the compacted sandy soil and over-consolidated clay with finite element method （FEM）, because they have obvious shear dilatation during the shearing process; But for the loose earth （underconsolidation soil）, the associated flow rules should be used because of its shear contraction As for normal consolidated soil , the dilatancy angle should be reduced, it is suggested that the value of dilatancy angle taken as one third to one second of internal friction angle.

关 键 词：边坡 剪胀性 流动法则 塑性区 潜在滑动面 非线性有限元法 固结 

分 类 号：TU457[建筑科学—岩土工程] P642.22[建筑科学—土工工程]