开挖对边坡变形影响的离心模型试验研究

边坡开挖是工程中经常遇到的问题。采用清华大学土工离心机以及新开发的开挖模拟设备进行了土坡开挖的离心模型试验，测量了开挖过程中边坡位移场的变化。基于位移测量结果提出了一种确定开挖影响范围的方法，分析了开挖后边坡的变形响应。结果表明：开挖后坡体内部根据竖向应变性质的不同可分为开挖松动区、开挖压缩区和无影响区3个区域，不同区域土体的变形特性有所差别。开挖后边坡内部的潜在滑裂面在变形破坏过程中是变化的，从坡体内部向坡面方向移动。开挖条件下边坡表现出明显的渐进破坏过程。

Centrifugal model tests on excavation-induced deformation of slopes

The problems induced by slope excavations are quite common in practice. Centrifugal model tests are conducted to investigate behaviors of cohesive slopes under excavation conditions using the excavation simulation devices on the centrifuge of Tsinghua University. The displacement fields are measured during excavation. A method is proposed to identify the excavation influence areas during excavation basing on the displacement measurements, and the deformation of a slope is also analyzed. The results show that the slope can be divided into three areas with different deformation features: excavation-induced relaxation area, excavation-induced compression area and non-influence area, in which the vertical strains are negative, positive and almost zero, respectively. Meanwhile, the potential slip surface moves during the process of deformation, which gradually spreads from the inner to the slope surface after excavation. The excavation causes a significantly progressive failure of the slope.