Abstract

Assuming that relative sliding does not occur to the coordinated deformation of bolt/cable and surrounding rock, a constitutive model of coupling effect between bolt/cable and creep surrounding rock is established to study the variation law of anchorage force on surrounding rock with time increasing, the parameters of physical-mechanics of bolt/cable and the mechanical parameters of surrounding rocks analyzed, and the sensitivity of the above parameters to anchorage force compared using sensitivity analysis method. Results show that the validity and effectiveness of the proposed constitutive model is verified by numerical simulation. And the main factors affecting the anchorage force for creep rock are diameter (D), elastic modulus (E ^c), and initial pre-stress force (F) of bolt/cable, viscoelastic modulus (E ^R), viscoelastic coefficient (η ^R) and initial in situ stress (σ ₀) of surrounding rocks, respectively. For bolt or cable, increasing the parameter values of D, E ^c and F can strengthen the anchorage force; while for surrounding rocks, large value of σ ₀ and small value of η ^R are beneficial to the exertion of anchorage force. The sensitivities of these factors from high to low are D, E ^R, σ ₀, E ^c, F, η ^R, respectively. The result can provide some guidance for the formulation of on-site support scheme and parameters selection.

摘要

假设螺栓/电缆与围岩的协调变形不发生相对滑动，建立了螺栓/电缆与蠕变围岩耦合效应的本构模型，研究了锚固力对围岩随时间的变化规律，分析了锚索物理力学参数和围岩力学参数，并利用灵敏度分析方法比较了上述参数对锚固力的敏感性。结果表明，所建本构模型的有效性和有效性通过数值模拟得到了验证。影响蠕变岩石锚固力的主要因素是直径（D），弹性模量（E ^c）和初始预应力（D）。˚F）螺栓/电缆，粘弹性模量（的ë ^[R ），粘弹性系数（η ^{- [R} ）和初始原地应力（σ ₀分别围岩，的）。对于螺栓或电缆，增加D，E ^c和F的参数值可以增强锚固力；而对于周围的岩石，的大的值σ ₀的小值η ^{- [R}是的锚固力的发挥有益的。这些因素从高至低的敏感性是d，ê ^{- [R} ，σ ₀，ê ^Ç，˚F，η ^{- [R} ，分别。研究结果可为现场支持方案的制定和参数选择提供指导。