外部连接全长黏结式锚杆和弹力式锚杆抗爆加固效果模型试验研究

RESEARCH ON ANCHORAGE EFFECTS OF FULLY CEMENT-IMBEDDED OUTSIDE-CONNECTED ROCK BOLTS AND ELASTIC-CONNECTED ROCK BOLTS IN ANTI-EXPLOSION REINFORCEMENT MODEL TEST

利用实验室抗爆模型试验装置,研究在平面装药爆炸应力波的作用下,外部连接全长黏结式锚杆和弹力式锚杆对洞室围岩的不同加固效果。通过分析自由场爆压时程曲线,发现该试验仪器测试效果较好,并分析和比较2种锚杆加固所造成的洞室围岩拱顶位移、洞壁应变和拱顶、底板及侧墙加速度的差别。试验结果表明:经过外部连接全长黏结式锚杆加固的洞室比弹力式锚杆加固的洞室拱顶位移峰值减少明显;在平面波的作用下,3个洞室洞壁各个位置都是产生压应变,最大应变出现在拱脚处;拱顶加速度是振动最激烈的地方,底板加速度在变形不大时加固洞室增加较大,必要时应该采取减震措施;对比2个加固洞室的最大应变峰值和加速度,发现外部连接全长黏结式锚杆相对较小,说明对洞室围岩的加固宜采用外部连接全长黏结式锚杆。

Based on anti-explosion reinforcement model test device, the different anchored effects on the tunnel, which is reinforced by fully cement-imbedded outside-connected rock bolts and elastic-connected rock bolts are studied under explosive stress waves produced by plane charging. It is proven that testing instruments are affected by pressure time-dependent curves of free field. For the purpose of the comparison of anchorage effects of two kinds of rock bolts, the differences of arch vault displacement of two underground openings, the surface strain of two underground openings, and the acceleration of roof, floor and ribs of two underground openings are all analyzed. The results show that the arch vault displacement of the tunnel reinforced by fully cement-imbedded outside-connected rock bolts is reduced more significantly than that of the elastic-connected rock bolts compared with that of tunnel without support system. Surface strains of three underground openings are pressed under plane explosive stress waves; and the largest value is found on arch foot. It is also shown that the maximal acceleration is located on the roof; and the accelerations of floors of two underground openings reinforced are increased under the condition of small deformation by adopting some vibration-absorptive ways. Compared with the maximal surface strain and acceleration of two underground openings reinforced, those of the tunnels reinforced by fully cement-imbedded outside-connected rock bolts are relatively small, indicating that the fully cement-imbedded outside-connected rock bolts should be more suitable for the surrounding rock of underground openings than the elastic-connected rock bolts.