静载作用下锚杆拉拔数值模拟分析

Numerical Simulation Analysis of Bolt Drawing under Atatic Load

使用有限差分程序FLAC3D建立锚杆拉拔计算模型,分析对比单锚和多锚对同一土体的影响,揭示了不同孔径锚固体在同一拉拔力下受力规律和土体位移规律。结果表明:锚杆自上而下发挥作用,锚杆直径相同、锚固深度相同,锚杆顶端位移与荷载成正比;锚杆的极限拉拔力随锚固体半径增大而提高;同一孔径的锚固体在相同的锚固深度处,界面剪应力随拉拔力增大而增大;同一孔径的锚固体在同一锚固深度施加相同拉拔力,界面剪应力随锚固体孔径增大而减小。同时经过对比分析发现,单锚的锚固效果较多锚较差,在相同拉拔荷载下,多锚锚固下土颗粒相互挤密,锚土结合力与土体稳定性较强。

This paper used the finite difference program FLAC3 D to establish the calculation model of bolt drawing, analyzed and compared the influence of single anchor and multiple anchors on the same soil, and revealed the stress law and soil displacement law of anchor solids with different pore sizes under the same pulling force.The results show that: the bolt acts from top to bottom, the diameter of the bolt is the same, the depth of the bolt is the same, and the displacement of the top of the bolt is proportional to the load;the ultimate pulling force of anchor increases with the increase of anchor solid radius;for the anchor solid with the same pore size at the same anchorage depth, the interfacial shear stress increases with the increase of pull-out force;the same pulling force is applied to the anchor solid with the same pore size at the same anchorage depth, and the interfacial shear stress decreases with the increase of the anchor solid pore size.At the same time, through comparative analysis, it is found that the anchoring effect of single anchor is less than that of multiple anchor.Under the same drawing load, the soil particles under multiple anchors are crowded together, and the bonding force of anchor soil and soil stability are strong.