基于Hoek-Brown应变软化模型的深部巷道锚杆受力特征研究

Characteristic Analysis of Deep Roadway Bolt Based on Hoek-Brown Strain Softening Model

基于量化GSI围岩评级系统及Hoek-Brown应变软化模型,应用FLAC3D数值模拟软件,分析全长粘结锚杆在不同长度及不同本构模型条件下的受力特点,对比分析不同预应力对锚杆轴力及剪力的影响。结果表明:采用理想弹塑性模型与应变软化模型计算得到的锚杆轴力及剪力相差较大;通过现场实际应用可知,应变软化模型能够较为真实地反应围岩的屈服破坏过程,在支护结构设计中,建议采用应变软化模型进行计算,可得到较为精确的计算结果。

Based on the quantitative GSI rock mass rating system and Hoek-Brown strain soften- ing model and using the FLAC3D numerical simulation software, we analyse the stress characteristics of fully grouted bolts in different lengths and different constitutive models and study the influence of different prestressed bolt axial forces and shear forces. The results show that on the basis of the ideal elastic-plastic model and strain softening model, the bolt axial force and shear force are quite different. The practical application shows that strain softening model could really give the response of surrounding rock in yield failure process. In the design of supporting structure, using the strain softening model can get more accurate results.