河岸边坡稳定性及张裂缝最不利位置研究  

Critical position of tensile cracks and stability analysis in slope near river

作　　者：邓东平[1] 李亮[1] 赵炼恒[1] 

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《中南大学学报（自然科学版）》2013年第9期3873-3883,共11页Journal of Central South University:Science and Technology

基　　金：教育部博士研究生学术新人奖项目(114801045);湖南省研究生科研创新项目(CX2012B058);贵州省交通运输厅科技项目(2010-122-020)

摘　　要：考虑坡外水位、坡顶荷载、地震作用和坡趾淘蚀等一般情况,对典型河岸边坡模型进行受力分析;采用极限平衡方法建立统一的安全系数计算公式,并推导出张裂缝最不利位置的解析式。通过算例对比,验证推导公式的正确性,并研究坡外水位、坡顶荷载、地震作用、张裂缝深度及积水深度变化时对河岸边坡的张裂缝最不利位置及稳定性的影响。研究结果表明:流水冲刷引起坡趾区域的淘蚀显著降低了原状河岸边坡的稳定性,同时使得张裂缝的最不利位置较原状河岸边坡更临近坡顶点,使之成为引起河岸边坡塌方的一个重要原因;坡外水位的升高对原状河岸边坡和流水淘刷后河岸边坡的张裂缝最不利位置及稳定性的影响不同,且后者较前者对坡外水位突升所引起的稳定性问题更加明显;地震作用、张裂缝深度及积水深度的变化对河岸边坡的张裂缝最不利位置及稳定性影响较大,而坡顶荷载的变化对其影响较小。Considering the general situation like water level outside slope,loads on top of slope,earthquake and erosion of slope toe,all forces were analyzed in typical model of slope near river.Uniform formula for calculating factor of safety(FOS) was obtained based on the limit equilibrium method,and the analytical formula of the critical position of tensile cracks was derived.Through comparison of some examples,the correctness of these derived formulas was verified,and the effect on the critical position of tensile cracks and slope stability with the change of water level outside slope,loads on top of slope,earthquake,depth of tensile crack and water level of tensile crack was discussed.The results show that erosion of slope toe caused by scoring of flowing water significantly reduces stability of the original state slope near river,and makes the critical position of tensile cracks more close to the top point of slope than the original state slope near river,so it becomes an important reason of the closer collapse of the slope near river.The effect of the increase of water level outside slope on the critical position of tensile cracks and slope stability is different between the original state slope near river and slope near river after scoring of flowing water,and the instability of the latter caused by the increase of water level outside slope is more obvious than the former.Earthquake,depth of tensile cracks and water level of tensile cracks have great impact on the critical position of tensile cracks and stability of slope near river,but loads on top of slope have a little impact.

关 键 词：河岸边坡 张裂缝 稳定性分析 安全系数 最不利位置 

分 类 号：TV223[水利工程—水工结构工程]