喷锚初期支护——围岩稳定性强度折减有限元分析

摘要

The overall stability evaluation of tunnel surrounding rock mass with primary shotcrete and rock bolts in construction stage is very important for construction safety. Based on geologic conditions of class IV surrounding rock mass in one constructing tunnel, the safety factor of the overall stability of tunnel surrounding rock mass with shotcrete and rock bolts is investigated using ABAQUS through three-dimensional (3D) finite element strength reduction technique coupled with the Hyperbolic Drucker-Prager elasto-plastic model, which takes into account the interaction between the shotcrete lining and rock mass, the interaction between the rock bolts and rock mass. On the basis of analysis of the calculated results, this paper presents a criterion of limit state of tunnel instability. It is reasonable that the safety factor is calculated by the proposed limit state criterion.%岩石隧道施工阶段具喷锚初期支护的围岩稳定性评价对隧道施工安全是非常重要的.根据一施工中的岩石隧道IV级围岩地段地质条件为基础,选用ABAQUS程序双曲线型D-P材料模型为岩土体破坏准则,建立了考虑喷射混凝土与岩体之间,锚杆与岩体之间相互作用的3-D有限元计算模型,以此模型利用强度折减技术研究了具锚喷初期支护的围岩稳定性安全系数.分析表明采用所提出的极限状态确定具喷锚支护的围岩稳定性安全系数是合理的.