土层锚固体应力传递机制

基于锚固体轴对称受力特征开发了一种土层锚固界面试验装置，结合二维数字散斑相关方法，获得随着荷载加大锚固体周边土体的位移场及应变场变化规律。试验结果表明，锚固体的位移带动周边土体变形主要出现在靠近锚固体的一小薄层范围内，其变形具有范围稳定、连续、线性和剪胀等特征。采用与Coulomb屈服条件相关联的流动法则建立锚固体界面层的本构关系，并推导出了锚固体在拉拔荷载条件下的轴力和剪应力分布的表达式。分析结果表明，锚固体上的剪应力分布的均匀程度与土层密实度密切相关，土层的密实度越低，其抗力系数、内摩擦角越小，则锚固体上的剪应力分布越均匀，而抗力系数和内摩擦角较大的土层，其剪应力分布特征与岩石锚固体的理论及实测成果相似。

Stress transfer mechanism of soil anchor body

Based on the characteristics of stress axisymmetric of the anchorage body, an experimental device of anchor-soil interface is developed. By means of 2D digital speckle correlation method, the displacement field and the strain field of soil surrounding anchorage body are obtained. Experimental results show that, the deformation of the surrounding soil caused by the displacement of the anchor is mainly in a small thin layer that is near the anchorage body, and its deformation is characterized by stable range, continuous, linear and shear dilation. On this basis, the constitutive relationship of the anchorage body interface layer is established according to the flow rule associated with Coulomb yield condition, and then the expressions of axial force and shear stress distribution under the condition of drawing load are deduced. The result indicates that the degree of uniformity of shear stress on anchorage body is closely related to soil compactness. The lower the soil compaction, the smaller the resistance coefficient and the angle of internal friction, and the shear stress distribution is more uniform on the anchor. While for the soil with larger resistance coefficient and internal friction, the shear stress distribution is similar to the theory and measured results of the rock anchor solid.