基于损伤理论的全长式锚杆荷载传递机理研究

根据损伤理论的基本原理,定义岩土体剪切损伤变量及其相应的损伤演化方程;依据岩土体在剪切应力作用下的损伤特性和锚杆在岩土体中的荷载传递机理,建立锚杆在岩土体损伤时的荷载传递微分方程并推导出锚杆轴力、剪切位移和侧摩阻力沿着锚杆长度分布的解析解,该理论解答综合考虑锚杆长度、锚杆直径和岩土体的损伤特性、剪切模量及压缩模量等因素的影响。然后利用数值分析的手段对锚杆的轴力和侧摩阻力与损伤变量、锚杆长度及锚固体直径之间的关系进行分析。最后利用一组有效的试验值与上述模型进行对比分析,显示该模型的合理性。

Study on Load Transfer Mechanism for Span-type Anchor Based on the Damage Theory

According to the basic damage principle, the shear damage variable of rock is defined and the damage evolution equation is suggested. In terms of the mechanism of anchor load transfer considering the damage of rock-soil mass, the analytical solution about the axial force and frictional resistance along the anchor length is given. The factor of the characteristics of damage, anchor length, anchor diameter, and module of shear and compression are included in the analytical solution. The above solution is credible and accurate by analysis. And then, the relation between the axial force and side frictional resistance force and the damage variable of soil and anchor length and diameter is analysed by using the numerical calculation method. The experimental results are in good coincidence with the theoretical prediction.