恒阻大变形锚杆/索力学特性数值模拟研究

Numerical simulation research on mechanical properties of constant resistance bolt/cable with large deformation

具有大变形特性的材料在抵抗岩体冲击、剪切和能量吸收等方面比传统意义下的小变形材料表现出更为优异的性能。针对普通锚杆/索无法抵抗软岩大变形而被拉断破坏等问题,何满潮研发了新型恒阻大变形锚杆/索,并成功应用于矿山灾害控制领域,然而针对恒阻大变形锚索吸能特性及其大变形数值模型构建尚属研究空白。本文首先通过室内实验揭示恒阻大变形锚杆/索(NPR)在静力拉伸和动力冲击条件下的吸能特性;然后利用Fish语言首次构建NPR锚杆/索数值分析模型,针对动/静条件下的NPR锚杆/索能量吸收规律进行数值模拟计算,并将试验结果与模拟结果进行对比分析,发现二者具有显著一致性;最后根据计算结果建立NPR锚杆/索与围岩体的相互耦合作用能量方程,揭示NPR锚杆/索在围岩控制全过程中的力学变化规律和能量吸收特征。

Materials with large deformation properties of resisting rock mass impact and shear and en- ergy absorption show better performance than traditional ones with small deformation. Therefore, for the problems of pulling off and destroying in ordinary bolts/cables, He Manchao developed a new type of bolt/cable with constant resistance and large deformation （energy-absorbing bolt/cable） and it is suc- cessfully used in the field of mine disaster control. However, it lacks to study the energy absorption characteristics of bolt/cable with constant resistance and large deformation and the numerical model of such large deformation. In this paper, the energy absorption characteristics of bolt/cable with constant resistance and large deformation under conditions of static tension and dynamic impact are firstly inves-tigated in laboratory experiments. Then, the numerical analysis model of NPR bolt/cable is constructed using the Fish language and the energy absorption law of NPR bolt/cable under dynamic/static condi- tions is numerically simulated. Comparing and analyzing the experimental results and simulation results, it is found that there is significant consistency between them. Finally, the energy equation of mutual coupling between NPR bolt/cable and surrounding rock mass is established according to the calculated results, which reveals the mechanical change and energy absorption characteristics of NPR bolt/cable in the total process of surrounding rock control.