岩体离层作用下锚杆受力特性全历程分析

 针对岩体离层作用下锚杆受力特性全历程分析问题，基于锚固界面的双指数曲线模型，采用荷载传递方法，建立离层作用下锚杆受力特性的非线性解答，分析离层发展全历程过程中锚杆轴力和界面剪应力分布，以及岩体离层–锚杆轴力曲线的特性，并采用模型试验数据进行对比验证。结果表明：锚杆轴向应变的计算值与实测结果基本一致。离层发展过程中，锚杆轴力呈现先增大后减小的特性，且在离层发展后期具有明显的非线性特征。离层产生的锚杆轴力和界面剪应力均呈现明显的不均匀分布和非线性特征，且二者均随着离层的发展向两端传递。离层位置对锚杆的受力特性有很大影响：离层位于锚杆中心时，其两侧的锚杆轴力与界面剪应力均成对称分布，且随着离层发展的演变规律相同；离层偏离锚杆中心时，两侧锚杆轴力与界面剪应力分布则明显不同，界面剪应力在离层位置处存在着跳跃点，且锚固长度较小一侧的锚固界面先产生塑性变形直至整体滑移破坏，决定了锚杆所能承受的离层和抗拔荷载大小。研究结果为岩体离层作用下锚杆的受力分析提供了理论参考。

Full-range analysis on mechanical characteristics of bolts in rock mass with bedding separation

The full-range analysis on the mechanical characteristics of bolts in rock mass with bedding separation was performed with the bi-exponential model for anchorage interface to derive the nonlinear solution based on the load transfer method. The full-range mechanical characteristics of bolts including the relationships between the bedding separation and axial force，axial force distribution and shear stress were discussed. Validity of the proposed approach was verified by the experimental results. The results show that the calculated axial strain along the bolts has good agreement with the measured values. During the expanding process of bedding separation，the axial forces of the bolts increase initially and then decrease nonlinearly. The axial force and shear stress distribute unevenly along the bolts，and are transferred to both ends with the expanding of bedding separation. The location of bedding separation affects the mechanical characteristics of bolts significantly. The axial force and shear stress distribute symmetrically when the bedding separation locates at the middle of bolts. Otherwise，the axial force and shear stress show distinguishing distribution and evolution features at both sides，and the shear stress has a jump at the location of bedding separation. The interface with the shorter anchorage length yields the plastic deformation and even slipping failure in advance，which determines the bearing capacity of bedding separation and tensile load of bolts.