黏土坡稳定性的断裂力学分析  

Fracture mechanics analysis on stability of clay slope with crack

作　　者：张廼龙[1] 郭小明[1] 王向东[2] 

机构地区：[1]东南大学土木工程学院,南京210096 [2]河海大学土木工程学院,南京210098

出　　处：《东南大学学报（自然科学版）》2010年第5期1029-1033,共5页Journal of Southeast University：Natural Science Edition

基　　金：江苏省基础研究计划资助项目(BK2009259)

摘　　要：采用线弹性断裂力学方法分析了黏土坡的断裂机理,结合有限元模型,对黏性土坡顶裂缝进行计算.分别得到了黏性土坡顶最易开裂位置和坡顶不同位置处裂缝的临界缝长随坡高和坡角的变化曲线以及坡顶裂缝的倾斜角与缝端等效应力强度因子关系曲线.结果表明:最易开裂位置随坡高或坡角的增加移向坡背一侧;离最易开裂位置越远,临界缝长越长;同一位置倾斜角不同的裂缝对竖向裂缝端部等效应力强度因子偏差微小,倾斜裂缝可以近似作为等长竖向裂缝处理.在此基础上给出了评价坡顶裂缝稳定性准则.实例显示,断裂力学方法能够简单、有效地分析黏土坡稳定性,为黏土坡的设计运行提供指导.The fracture characteristics of clay slope are computationally studied with the fracture mechanics method in finite element models.The most easily crack position（MECP） is investigated.The curves of the most easily crack position（MECP） versus slope heights and slope angles are presented quantitatively and separately.The curves of critical crack length（CCL） of different position versus slope heights and slope angles are also presented quantitatively and separately.At the same time,the curve of equivalent stress intensity factor（ESIF） versus the angle between crack and its left bank is obtained.The computational results show that the most easily crack position（MLCP） moves towards slope back away from slope face as the increase of slope height or slope angle;the critical crack length（CCL） of different position shortens as the increase of slope height but lengthens as the increase of slope angle.The results also show that the critical crack length（CCL） lengthens as the increase of distance from crack to the most easily crack position（MECP）.The equivalent stress intensity factors（ESIFs） of several tilt cracks with different angle are computed.The deviation ratios of equivalent stress intensity factor（ESIF） of tilt cracks to equivalent stress intensity factor（ESIF） of vertical crack are no more than 4.5%.Therefore,tilt cracks can be treated as vertical crack in engineering practices.Based on those results,a criterion on crack stability is presented to control and monitor the slope safety during its design and running period.

关 键 词：黏土坡稳定性 断裂力学 最易开裂位置 临界缝长 判定准则 

分 类 号：TU43[建筑科学—岩土工程]