锚杆扩大头不同受力方向对其承载能力影响机制探究

Influence Mechanism of Different Stress Directions of Bolt Enlarged Head on Bearing Capacity

扩体锚杆是工程加固中极为重要的一部分,通过扩体锚杆不同受力方向对其承载能力影响机制探究,总结了扩体锚杆的破坏形式及拉拔力计算公式,探究了40°,50°,60°,70°,80°,90°等多个角度下注浆体形状的最大拉拔力,确定注浆体的最佳形状为锚杆与承压面的最佳夹角为50°。总结了不同偏拉角度下注浆体、圆盘随着偏拉角度的增加应力分布形式变化规律,发现在内部圆盘与锚杆的连接处容易产生应力集中现象,在锚杆支护加固设计时可以对该连接处进行监测预警,降低工程事故造成的人员伤亡和经济损失。

Expanded bolt is an extremely important part of engineering reinforcement. Through the exploration of the influence mechanism of different stress directions of expanded bolt on its bearing capacity, the failure form of expanded bolt and the calculation formula of pullout force are summarized, and the maximum pullout force of the shape of grouting body at 40 °, 50 °, 60 °, 70 °, 80 °, 90 ° and other angles is explored. It is determined that the best included angle between the bolt and the bearing surface is 50 °. The change rule of stress distribution form of grouting body and disc with the increase of deflection angle under different deflection angle is summarized, and it is found that stress concentration is easy to occur at the joint of internal disc and anchor bolt. In the design of bolt support and reinforcement, the joint can be monitored and forewarned to reduce casualties and economic losses caused by engineering accidents.