苏永华 张航 蹇宜霖

摘 要：研究了古滑坡的变形与其稳定性的关系.通过公式推导证明了在对古滑坡滑带进行力学参数折减过程中考虑刚度退化的必要性，提出考虑古滑坡滑带强度折减和刚度退化耦合作用的新方法，并给出了具体的耦合方式.依据大量的工程经验绘制古滑坡失稳变形曲线，提出古滑坡自稳能力预警位移值和极限位移值的概念和确定方法.最后结合工程算例，对全局强度折减、滑带强度折减、考虑滑带强度折减和刚度退化耦合作用的三种方法所得结果进行了对比分析，计算表明，采用考虑滑带强度折减和刚度退化耦合作用的方法分析古滑坡变形场更符合实际情况.

关键词：古滑坡；滑带强度折减法；刚度退化；耦合作用；自稳能力；最大变形量

中图分类号：P642.22 文献标志码：A

文章编号：1674—2974（2018）07—0077—08

Abstract： The relationship between the deformation and stability of the ancient landslide is studied in this paper. The necessity of considering the stiffness degradation in the process of reducing the mechanical parameters of the landslide is proved by the formula derivation， and a new method that considers the coupling effect of stiffness- and strength- degradation is presented. The deformation curve of the instability in the ancient landslide is drawn by a large number of engineering experiences， and the concepts about the warning displacement value of self-stabilizing ability and the ultimate displacement value of ancient landslide are put forward and defined by a determined method. Comparing with the methods of global strength degradation and slide zone strength degradation and the method in this paper applied to actual engineering example， it is seen that the method in this paper is more realistic to analyze the deformation field of the ancient landslide.

Key words： ancient landslide；slide zone strength reduction；stiffness degradation；coupling effect；self-stabilizing ability；maximum deformation

古滑坡在世界各地山区普遍存在[1-2]，其在滑动过后的漫长地质年代历程中，滑体、特别是滑带岩土体的重新固结和进一步胶结，使滑坡在总体上具有一定的完整性，内应力场平衡，处于稳定状态.在山区公路选线的调查中可见，某些民居即建在古滑体坡度较平缓部位，长年来安然无恙，这表明古滑坡自身能够抵抗一定程度的扰动或对某些扰动方式不敏感，具有一定的自稳能力.研究并评估古滑坡的自稳能力对急需大规模进行的山区建设有一定指导作用.

目前对滑坡稳定性的评价主要是利用极限平衡法[3-5]和数值分……