水平地应力对下向进路可动块体稳定性影响的分析

Stability Analysis on the Movable Block Formed in the Underhand Cut-and-fill Drift under Horizontal Crustal Stress

地应力对深部地下洞室围岩的稳定性有很大程度的影响,其中水平地应力分量起关键作用。针对下向进路侧帮可动块体的形成条件及受力状态,利用矢量分析及力学计算,提出了考虑水平地应力的可动块体稳定性系数的计算方法。在此基础上,分析了最大水平主应力方向与进路方向呈不同交角时,主应力对可动块体稳定性的影响。分析表明,在一定的块体形成条件下,水平主应力对可动块体稳定性的影响与水平主应力的作用方向密切相关。随着最大水平主应力方向与进路方向交角的增大,主应力对可动块体稳定性的影响程度逐渐减小,交角在0~30°之间变化时,块体稳定性系数减少较快,随交角的增大,块体稳定性系数变化趋于平缓。将本计算方法应用于工程实践中,取得了良好效果。

The stability of surrounding rock in underground cavity is mainly affected by ground stress,and the horizontal crustal stress component is the critical influencing factor.According to the forming conditions and the stress state of the movable block formed in the underhand cut-and-fill drift,a stability analytic method considering the horizontal crustal stress was presented by vector algebra and mechanical analysis.Then the impact of the horizontal crustal stress on the movable block's stability was studied when the maximum horizontal crustal stress direction and the underhand cut-andfill drift direction were in different angles.Results showed that the stability of the movable block was closely related to the acted direction of the horizontal principal stress.The degree of impact on the stability of the movable block decreased gradually with the increase of the angle between the horizontal crustal stress direction and the underhand cut-and-fill drift direction.The block stability coefficient decreased faster when the angle changed during 0to 30degrees.As the angle increasing,the changes of the block stability coefficient tended to be gentle.Good results of this calculation method were achieved in engineering practice.