岩体隧道锚固作用分析

Analysis of anchoring mechanism of underground rockmass tunnel

在工程实例中利用数值模拟方法对考虑和不考虑松动圈的岩体,在不同工况下锚杆加固前后的径向、环向应力,径向、环向位移以及锚杆轴向应力进行全面比较分析。研究锚杆和松动圈对隧洞围岩力学性质的影响,结果表明考虑和不考虑松动圈相比,洞室表面径向位移要明显大一些,而且外界载荷越大,二者的差值越大;在锚杆加固作用下环向应力峰值无论是否考虑松动圈,其出现位置都较加固前向洞壁方向移动,同时围岩径向位移在加固前后变化很大,随着外界载荷的增大,径向位移减小越明显。锚杆支护的主要作用之一是控制围岩的变形和发展,通过锚杆加固改善应力环境来提高围岩的稳定性。

The underground tunnel anchoring mechanism is analyzed by using the numerical simulation method.In the case study, considering the existence and nonexistence of the loose loop,anchoring effect of the bolt on the wall rock mechanical properties is studied by analyzing the radial displacement and stress,the hoop displacement and stress of the wall rock and the axial stress of bolt. The radial displacement of the chamber surface in the loose loop model is larger than that in the no loose loop model.Under the action of the bolt,the place of peak value of the hoop stress is more approach the chamber wall.It indicated that one of the main functions is to control the displacement and bolt to enhance the stability of the wall rock through improving the stress state.