摘要
根据变形协调原则,认为对数螺旋线滑面滑坡体在下滑过程中并非完全不变形而是根据滑面形状自适应变形从而产生能量耗散。为量化该过程中的能量耗散,根据协调速度场的关系提出了2种多块体划分法来计算该变形摩擦耗能功率,并结合极限分析上限法和强度折减法推导了预应力锚索加固边坡的安全系数计算式。通过算例分析表明,虽然2种多块体划分方法获得的边坡安全系数随着划分块体接触面数量的增加变化规律不同,但最终都趋于稳定收敛,且收敛值十分接近,并从具体划分原理角度解释了2种不同变化趋势的原因。典型边坡算例的不同分析方法安全系数结果比较表明,滑坡体内部变形摩擦耗能有助于提高边坡的抗滑作用,安全系数较不考虑时有所增大。分析总结了预应力锚索边坡随锚索预应力、锚索倾角、锚索位置高度变化条件下有无考虑滑坡体内部变形摩擦耗能的边坡安全系数变化规律。该方法弥补了以往上限法中忽略该项摩擦耗能的不足,可为预应力锚索加固边坡的稳定性分析提供参考。
According to deformable coordination condition, the sliding soil mass will deform to adapt to the curve of logarithmic spiral which will lead to energy dissipation. To quantify this energy dissipation, two multi-blocks partitioning methods which are based on the coordinating velocity field are proposed. Combined with the upper bound limit analysis and the strength reduction method, the safety factor of the case of reinforced slopes with prestressed anchor cables is obtained. The calculated results indicate that the influence rules of interface number on the safety factor in the two multi-blocks partitioning methods are different, but both curves converge to a similar value, and the reasons for this are explained from the point of partition principles. The safety factors of typical slopes are calculated and compared with others＇ results. It is indicated that the safety factor considering the energy dissipation due to deformation of inner friction is more than the other one, and this energy dissipation contributes to improving the anti-sliding ability of slopes. Moreover, the influences of anchor prestress, anchor inclination and anchor height on the safety factor are respectively analyzed, and in each calculation, two results with and without considering the energy dissipation due to deformation of inner friction are compared. This method makes up for the deficiency of neglecting the energy dissipation due to deformation of inner friction, which can provide references for stability analysis of reinforced slopes with prestressed anchor cables.
作者
夏元友
陈春舒
XIA Yuan-you CHEN Chun-shu(School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, Chin)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2017年第2期210-217,共8页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金面上项目(51374163)
关键词
预应力锚索边坡
稳定性
上限分析
耗能
多块体划分法
reinforced slope with prestressed anchor cable
stability
upper bound limit analysis
energy dissipation
multi-blocks partitioning method
