浅埋缓倾斜薄层金属矿长壁开采顶板响应及力学分析

为研究长壁开采工艺在浅埋缓倾斜薄层金属矿开采过程中的适用性,以某金属矿赋存环境为背景,基于室内相似配比试验结果制备大尺寸地质力学模型,开展长壁回采工艺下浅埋采场相似物理模型试验。试验结果表明:顶板初次断裂步距为32 m,回采前24 m采场顶板较稳定;24~32 m回采过程中,每次回采沉降值以4倍左右速率增大;采场顶板长度接近初次断裂步距时,回采中顶板沉降量增大,且回采结束后顶板沉降响应明显。引入简支梁力学分析模型,基于弹性力学理论分析顶板采动响应特征规律,结合岩梁参数,简支梁弹性力学得到的顶板初次断裂步距为36.2 m,相似模型试验与力学分析结果较吻合。

Roof Response and Mechanical Analysis of Longwall Mining in Shallow Gently Inclined Thin Metal Mine

In order to study the applicability of longwall mining technology in shallow gently inclined thin metal ore mining process, taking the occurrence environment of a metal ore as the background, a large-scale geomechanical model was prepared based on the indoor similar ratio test results, and the similar physical model test of shallow stope under longwall mining technology was carried out. The test results show that the initial fracture step of roof is 32 m, and the roof of stope 24 m before mining is relatively stable. In the process of 24~32 m stoping, the settlement value of each stoping increases by about 4 times. When the length of stope roof is close to the first fracture step, the roof settlement during mining increases, and the roof settlement response is obvious after mining. The mechanical analysis model of simply supported beam is introduced,and the characteristics of roof mining response are analyzed based on elastic mechanics theory. Combined with rock beam parameters, the initial fracture step of roof obtained by elastic mechanics of simply supported beam is 36.2 m, and the results of similar model test and mechanical analysis are consistent.