采空区群动力响应的类层间剪切模型法研究

为研究采空区群内岩体介质动力响应特性,提出采空区群动力响应的类层间剪切模型法。通过将上覆岩层等效为由"虚拟间柱群"和集中质量块组成的系统,将周边围岩等效为剪切力Q的作用,构建采空区群类层间剪切模型,建立采空区群内岩体介质的动力响应微分方程;考虑到单元空区的赋存深度和构成形状特征,引入剪切力影响因子δ,修正围岩的剪切力作用。以某金矿5个中段采空区组成的采空区群为例,利用数值分析法与该分析方法进行对比分析。结果表明:上述采空区群赋存环境的等效方法具有可行性;采空区群岩体在其内部阻尼及外部围岩剪切力的双重作用下,作振幅衰减振动;类层间剪切模型法和数值分析法计算记录点的位移、速度时程曲线趋势一致、幅值相近,但前者运算时间更短、效率更高。类层间剪切模型法为研究采空区群动力响应特性提供了一种新思路。

Research on the method of similar layer shearing model for dynamic respones of goaf group

In order to investigate the dynamic response of goaf group ,the method of similar layer shearing model for dynamic response of goaf group was presented .The overburden rock was e-quivalent to a system composed of the"virtual inter column group" and the lumped mass block , and the surrounding rock was equivalent to shear force Q .The similar layer shearing model of goaf group and the corresponding dynamic differential equations were established to study the dis-placement and velocity response of rock mass media in the goaf group .Considering the occurrence depth and the shape feature of the element goaf ,the influence factor of shear stress δwas intro-duced to modify the shear stress of surrounding rock .Taking the goaf group formed by 5 gobs in a gold mine as an example ,the method w as tested by using numerical simulation method .Results indicated that the equivalent method of goaf group environment mentioned above was feasibility ;the rock mass got in damped vibration under the double action of the internal damping and the shear force of the surrounding rock ;the conclusions of two methods were consistent and the am-plitudes were similar ,but the former operation time was shorter and the efficiency was higher .The method of similar layer shearing model provides a new way to study the dynamic response of the goaf group .