玄武岩纤维锚杆加固岩体的夹持效应

Clamping Effect of a Rock Mass Strengthened with the Basalt Fiber Reinforced Polymer Bolt

新型锚杆与新型锚固体系研究在边坡锚杆支护手段优化中有广阔前景。通过玄武岩纤维复合筋材替代传统钢锚杆,将隧道锚夹持效应进行拓展,提出交叉式布置玄武岩纤维锚杆锚固体系,推导交叉式锚杆锚固体系界面荷载的控制方程,并对该结构的加固岩体的加固效果进行有限元分析。结果表明:交叉式锚杆中部受到夹持效应影响,锚-岩界面应力达到峰值,带动周围岩体共同承受拉拔荷载。荷载响应初期锚杆夹持效应并不明显,当锚杆进入非线性位移阶段时,交叉式锚固体系的夹持效应发挥作用,使得该阶段锚固体系的承载能力相较于传统平行锚固体系大幅度提升。交叉式锚杆锚固角对该锚固体系的极限承载能力有较大影响,在工程设计时应进行优化分析确定优势锚固角。

The research on new type bolt and new type anchor system has broad prospects in the optimization of slope bolt support means.By replacing the traditional steel bolt with basalt fiber composite reinforcement,a cross arrangement basalt fiber bolt anchorage system was proposed,and the reinforcement effect of the structure on the rock mass was analyzed by finite element method.The results show that the stress at the interface between the bolt and rock reaches the peak value under the influence of the clamping effect in the middle of the cross bolt,which drives the surrounding rock mass to bear the pulling load together.At the initial stage of the load response,the clamping effect of the bolt is not obvious.When the bolt enters the nonlinear displacement stage,the clamping effect of the cross-bolt anchorage system plays a role,which makes the bearing capacity of the anchorage system at this stage greatly improved compared with the traditional parallel anchorage system.The anchorage angle of the cross bolt has a great influence on the ultimate bearing capacity of the anchorage system,and the optimal analysis should be carried out in the engineering design to determine the dominant anchorage angle.