摘要
矿山嗣后充填采矿过程中,矿柱与充填体易形成互相包裹的组合模型共同承受荷载作用。为了深入分析矿柱与充填体耦合接触面属性对组合模型宏观力学性能的影响,设计岩石-充填体耦合试件进行室内试验,将室内试验结果作为基准值,借助PFC颗粒流软件,通过采用控制变量法,调整岩-充耦合接触面细观属性,进行单轴压缩数值模拟试验。结果表明:岩-充组合模型受到切向、法向刚度及摩擦系数的共同影响,随着耦合接触面细观参数的折减而出现强度劣化;随着耦合接触面法向刚度的折减,模型宏观力学性能呈现出先剧烈后平缓的劣化趋势,当折减系数变为基础值的两个数量级范围时,模型峰值应力应变对其敏感性降低;随着耦合接触面切向刚度的折减,模型宏观力学性能呈现出剧烈-平缓-剧烈的劣化趋势,当折减系数变为基础值的一个数量级范围时,模型峰值应力应变对其敏感性降低;模型宏观力学性能与耦合接触面摩擦系数变化为正相关关系,其趋势随着摩擦系数的变化而近似线性变化。
In the process of subsequent backfilling mining,pillars and backfills are easy to form a coupled model encapsulated with each other to bear load together.In order to deeply analyze the influence of the contact surface properties of the pillar and the backfill on the macroscopic mechanical properties of the combined model,the rock-backfill specimens were fabricated for laboratory test.Based on the experimental results,the mesoscopic properties of rock-backfill coupled contact surface were firstly calibrated by control variable method,and then PFC software was applied to conduct uniaxial compression tests.The results showed that the tangential,normal stiffness and friction coefficient all had influences on the rock-backfill coupled model.The strength decreased with the decrease of the mesoscopic parameters of the coupled contact surface.As the normal stiffness of the coupled contact surface declined,the macroscopic mechanical properties of the model showed a tendency of deterioration from severe to gentle.When the reduction factor became two orders of magnitude of the base value,the sensitivity of the model’s peak stress and strain decreased.With the reduction of the tangential stiffness of the coupled contact surface,the macro-mechanical properties of the model showed a sharp-gradual-violent deterioration trend.When the reduction factor became an order of magnitude of the base value,the sensitivity of the model’s peak stress and strain decreased.The macroscopic mechanical properties of the model were positively correlated with the change of the friction coefficient of the coupling contact surface,and the trend varied approximately linearly with the change of the friction coefficient.
作者
王煜
付建新
杨子龙
WANG Yu;FU Jianxin;YANG Zilong(Civil and Resources Engineering School,University of Science and Technology Beijing,Beijing 100083,China;Key Laboratory of High-Efficient Mining and Safety of Metal Mines,Ministry of Education of China,Beijing 100083,China)
出处
《矿业研究与开发》
CAS
北大核心
2020年第3期113-118,共6页
Mining Research and Development
基金
国家自然科学基金青年项目(51804016).
关键词
岩石-充填体
耦合接触面
PFC数值模拟
单轴压缩试验
Rock-backfill
Coupled contact surface
PFC numerical simulation
Uniaxial compression test
