【作者】 雷涛；

【导师】 胡建华；

【作者基本信息】 中南大学 ， 采矿工程， 2010， 硕士

【摘要】 地下岩体的开挖引起原岩应力场扰动并使之重新分布,是一个典型的卸荷力学过程。对这一类问题,传统的加载分析方法由于忽略了卸荷效应的影响,导致分析结果与工程实际不相吻合。基于连续采矿的顶板诱导崩落技术具有创新高效的特点,而作为其工程对象的诱导岩体表现出典型的卸荷特征。因此,对诱导岩体进行卸荷分析,探讨岩体系统的稳定性、扰动力学响应以及岩体质量劣化规律,可更好地保障诱导崩落采矿技术的安全实施。以华锡集团铜坑矿92#矿体连续采矿顶板诱导崩落试验采场为研究对象,基于卸荷分析方法,针对地下采矿岩体工程的诱导效应问题进行了研究。主要研究内容包括：研究了采动卸荷岩体力学参数的劣化规律,基于影响区域理论对诱导岩体的卸荷带进行了划分,探讨了卸荷分析的方法和流程。构建了铜坑矿92#矿体连续开采的有限元模型,采用岩体动态力学参数开展了卸荷分析。结果显示：卸荷分析的顶板最大拉应力、下沉位移以及等效塑性应变分别达到1.5Mpa、20cm和1.5e10-2,较常规分析的1.0Mpa、13cm和0.9e10-2要大,与实际情况更为接近；连续采矿开采的最大步距为48m,表明在开采两个步距后,应当对顶板进行诱导处理。根据铜坑矿92“矿体连续开采顶板诱导崩落方案,运用ANSYS/LS-DYNA隐显式序列分析方法,探讨了在初始地应力场和扰动应力场条件下,爆破动载荷对卸荷岩体及其应力场的力学响应规律。基于岩石动力强度和破坏准则,以H-J-C损伤模型为蓝本,自定义了考虑岩体拉剪破坏的动力损伤材料模型；构建了卸荷岩体的单孔计算模型,研究了诱导岩体受爆破动载荷的损伤及其裂纹的扩展规律；构建了预裂缝的计算模型,模拟了预裂缝的形成过程,并结合现场电视钻孔试验分析了预裂缝形成过程中的力学效应。更多还原

【Abstract】 The excavation of the underground rock mass is a typical unloading mechanical process that brings redistribution of initial rock stress field. For this kind of problem, the traditional method of load analysis ignored the influence of unloading, which leads to the inconsistency between theoretical analysis and engineering practice. The technology of blast-induced caving roof which based on continuous mining is an innovative and efficient method. But the inducted rock mass, as engineering object which shows typical unloading features. Therefore, to better assure safety in practice of this technology, unloading analysis should be taken in the inducted rock mass, and the stability of the rock mass system, the deterioration laws of rock mass quality and disturbance mechanics effect of rock mass should be clearer understood. Took the No.92 ore body which adopted the blast-induced caving roof technology based on continuous mining in Tongkeng Mine as the experimental subject, by using the guidance of unloading rock mechanics theory, discussed the question of e induction effect of the rock mass engineering of underground mine. The main research contents as follows:The mechanics parameters deterioration laws of rock mass were studied, the unloading region of inducted rock mass was divided by the affect region theory, the method and flow of unloading mechanical analysis was analyzed.The continuous mining FE model of No.92 ore-body in Tongkeng mine was established, unloading effect was simulated using dynamic mechanical parameters. The result shows:the maximum tensile stress, subsidence displacement and equivalent plastic strain of roof rock mass were 1.5Mpa,20cm and 1.5el0-2 in the unloading analysis, and 1.OMpa, 13cm and 0.9e10-2 in conventional analysis; The values of unloading analysis are greater than conventional analysis, but closer to the actual situation; the maximum step in continuous mining is 48m which shows the roof should be inducted after 2 mining steps.Based on the continuous mining-induced caving roof option of the No.92 ore body in Tongkeng mine, by using Implicit-Explicit sequence calculation of ANSYS/LS-DYNA software, the mechanics responding law of inducted rock mass and its stress field was studied under the blasting loading on the condition of coupling effect by perturbation stress field and initial earth stress field.On the basis study of rock dynamic strength and failure criterion, the material constitutive model based on H-J-C damage model and dynamic damage of rock mass were established; The calculation model of single-hole was established, and blasting damage and fracture development of inducted rock mass was studied. The calculation model of pre-splitting crack was established, too. The forming process of pre-splitting crack and mechanic effect were analyzed, and the numerical result is verified by the experiment result of the borehole camera system.更多还原