考虑充填体支撑效应的矿岩-充填体相互作用机理分析

Interaction Mechanism of Ore-bearing Rock and Filling Body Based on Considering the Supporting Effects of Filling Body

为更好地研究矿岩和充填体的相互作用机理,依据充填体的不同硬化时期对顶板和矿岩所处的支撑效应,将充填体分为小变形阶段的弹性变形和大变形阶段的塑性变形,建立相应的充填体与围岩相互作用的悬臂梁+均布荷载及相关约束的力学模型。同时通过配比制作标准圆柱体,待强度稳定后进行切割打磨,在中间掏空20 mm厚度的半圆饼,并用水砂比为1∶12的配料进行充填。通过电阻应变片,测试试样在加载作用下的内部和表壁应变情况,分析接触带处的应力应变变化规律。进一步通过数值模拟软件,模拟相关过程,验证相关试验结果。模拟结果表明:随着加载的进行,接触带的应变变化增幅较大,在没有围压约束、轴向荷载作用情况下,充填体受压从临空面开始产生了剥落现象。围压约束有效增大了接触带区域的安全系数值,局部区域从塑性破坏区变成稳定区。

In order to better study the interaction mechanism of ore-bearing rock and filling body,according to the sup-porting effect of roof and ore-bearing rock in different hardening periods of the filling body,the filling body is divided into theelastic deformation in small deformation stage and plastic deformation in large deformation stage.The corresponding mechanicalmodel of cantilever beam ＋ uniform load and related restraints of the interaction of the filling body and the surrounding rock isestablished.At the same time,the standard cylinder is made based on the ratio,cutting and grinding are conducted after the sta-bility of the filling body strength,the semi-round cake with the thickness of 20 mm is hollowed out in the middle of standardcylinder,and it is filled with the materials with the water and sand ratio of 1∶12.Through the strain gauge,the variation regu-larities of stress and strain of the contact zone is analyzed by testing the internal and surface wall strain under the loading,be-sides that,the relevant process is simulated and relevant test results are verified by using numerical simulation software.Simu-lation results show that with loading,the stain variation increasing amplitude is big,under the condition of no confining pres-sure,with the action of axial loading,the spalling phenomenon of filling body caused from temporary surface.The safety coeffi-cient in contact zone is increased under the constraint of confining pressure,the local area is transformed from plastic failurezone to stable zone.