端锚可回收锚杆锚固段力学特征研究

RESEARCH ON MECHANICAL CHARACTER OF BONDING SEGMENT OF END-ANCHORED RETRIEVABLE RESIN BOLT

在对端锚可回收树脂锚杆和普通树脂金属锚杆结构分析的基础上,提出两种分析锚杆锚固段的力学模型;采用有限元数值分析软件对两种锚杆模型进行非线性分析,获得锚杆锚固段上剪应力和正应力的分布规律。然后,通过电测试验测量锚杆钻孔壁上的轴向应变,初步发现该应变的变化特性。最终揭示端锚可回收锚杆锚固段与围岩接触面上的应力分布规律:剪应力τ在钻孔底部附近取得最大值,自孔底向孔口方向递减;正应力σ也在孔底附近取得最大值,且表现为压应力,同样沿孔底至孔口方向递减。

Based on the analysis of end-anchored retrievable resin bolt and common resin metal bolt structures,a mechanical model of bonding segment is established.By means of the popular finite element software,a nonlinear analysis of these two kind of bolt model is conducted;and the distribution rules of shear and normal stresses in the bonding segment are found.Then,electrometric method is adopted to measure the axial strain on the wall of hole,and the variable character of the strain is found preliminarily,which basically reveals the mechanical character of the bolt′s bonding segment through those two methods.Such conclusions can be drawn:the shear stress on the contact surface of the bolt′s anchored part gets the maximum value at the bottom of the hole,and decreases in the axial directiont;he normal stress is compressive one,and its varying tendency is same with that of the shear stress;and the distribution rule of the strain is similar to that of the stress.