锚杆垫板形式对洞室抗爆效果的影响试验研究

Study of anti-explosion effects of tunnels with different forms of bolt bolster plates

为了研究爆炸条件下不同垫板形式锚杆对洞室加固效果的影响,现场试验中选择了平板和碗形两种不同的垫板形式。通过抗爆试验,对锚固洞室宏观破坏形态、洞壁位移特征、拱顶位移与比例距离之间的关系以及爆心两侧拱顶各点位移进行了对比,分析了两种垫板形式在爆炸条件下对洞室加固效果的影响。试验结果表明:在爆炸条件下,碗形垫板可以充分发挥锚杆抗拉能力高的特点,拱部围岩经碗形垫板加固后,整体刚度能够得到较大提高,对岩体的加固效果较好。

To study the reinforcement effects of different forms of bolt bolster plates under explosion,two different plates,namely face plate and bowl-shaped plate are selected in the field explosion test.Macroscopic failure pattern,displacement characteristics of tunnel wall,relationship between vault displacement and proportion distance,and vault displacements of both sides of explosion center are compared.Furthermore,reinforcement effects of the two plates on tunnels under the condition of explosion are analyzed.Test results show that bowl-shaped plate can bring tensile strength of bolt into full play;and stiffness of rock mass can be greatly improved.Reinforcement effect of bowl-shaped plate on rock are better than that of face plate.