深部巷道钻孔卸压机理及关键参数确定方法与应用

Borehole destressing mechanism and determination method of its key parameters in deep roadway

基于围岩强度参数衰减规律的室内试验结果,对FLAC3D应变软化模型进行了二次开发,以现场实测矿压显现规律作为已知特征值,反演了岩体力学参数。分析了深部巷道钻孔卸压机理,提出以应力转移效果及围岩变形控制效果作为卸压效果的直接评价指标,初步将卸压程度分为非充分卸压、充分卸压和过度卸压3类,系统研究了卸压钻孔参数(长度、直径和间排距)对深部巷道围岩稳定性的动态作用规律,提出了影响卸压效果的各关键参数的确定方法,完善了钻孔卸压技术体系。工程应用效果表明,采用卸压钻孔参数确定方法设计的卸压方案,围岩控制效果显著,且该方法简单易行。

Based on the strength degradation law of surrounding rock obtained from some experimental data,the strain softening model in FLAC3D was improved by a secondary development.The mechanical parameters of surrounding rock were derived by an inversion method using the measurement data of mine pressure as characteristic values.This paper proposed the assessment index for the effectiveness of borehole destressing,and the classification criteria for destressing degree.Through a systematic study about the effects of borehole parameters （length,diameters and inter-row spacing）on the stability of surrounding rock of deep roadway,the paper put forward a method to determine the key parameters influenced by borehole distressing,and then improved the technical system of borehole distressing.The practical application shows that the application of the borehole schemes determined by the proposed method can control the surrounding rock effectively.The method is simple to be mastered.