煤矸石风化强度特性及稳定性研究

发布时间：2018-05-07 20:18

本文选题：大型三轴试验 + 风化矸石　；参考：《重庆大学》2016年硕士论文

【摘要】：煤矸石是煤炭开采及洗选过程中产生的固体废弃物,是我国目前年排弃量和积存量第一的工业废渣。矸石散体粒径分布范围较大,数十厘米的石块到小于0.1毫米的细小颗粒都是其散体成分。其物质成分硬度相差甚远,从软岩到硬岩石均包含在内,还包含了部分残留煤,另外还有大量的有机质以及易挥发的可燃硫成分等,物理化学性质及力学特征明显不同于一般粘土、砂砾土及其它散体材料。煤矸石排弃后堆积成矸石山,矸石山露天堆放不仅会侵占农田,对水体、土壤以及大气均会产生严重污染,还可能产生自燃、爆炸等灾害。其风化后,煤矸石力学性质会产生变化,会产生结构损害、边坡稳定等环境岩土效应,不仅危及井筒运营的安全性,还对矿区内人员的生命财产安全产生严重影响。因此,我国急需解决矸石山所造成的环境影响及稳定性问题。本文针对重庆区域具有代表性的矸石山,以重庆某煤矿矸石山为研究背景,在现场试验及室内粗粒土大型三轴试验的基础上,从矸石风化特性出发,分析矸石风化强度特性,采用极限分析上限法及不平衡推力法分析矸石山的稳定性,并对矸石山的稳定性进行数值模拟分析,取得了如下成果:(1)通过筛分试验,测定重庆某煤矿矸石山新排矸石与风化矸石级配,并将筛分后的新排矸石配成与风化矸石相同的级配,以天然含水率与饱和含水率及不同围压为控制条件,然后通过室内粗粒土大型三轴试验,研究比较两种煤矸石的力学性质,对比分析了新排矸石及风化矸石三轴强度的力学性质。(2)运用不平衡推力法来推算重庆某煤矿矸石山的边坡稳定性;同时,针对矸石山体内滑移失稳模式,建立极限分析上限法分析重庆某煤矿矸石山的稳定性。(3)在分析煤矸石力学性质的基础上,采取对应的摩尔-库伦本构关系以及破坏准则,针对重庆某煤矿矸石山稳定性进行FLAC数值模拟,讨论重庆该煤矿矸矸石山的稳定性及其影响因素。
[Abstract]:Coal gangue is a kind of solid waste produced in the process of coal mining and washing. The particle size distribution range of gangue is large. The hardness of its material composition is very different, from soft rock to hard rock, it also contains some residual coal, in addition to a large amount of organic matter and volatile combustible sulfur, etc. The physical and chemical properties and mechanical properties are obviously different from those of clay, gravel and other bulk materials. Coal gangue is dumped and accumulated into gangue mountain, which can not only encroach on farmland, but also cause serious pollution to water body, soil and atmosphere, and may produce disasters such as spontaneous combustion, explosion and so on. After weathering, the mechanical properties of coal gangue will change, resulting in environmental geotechnical effects such as structural damage and slope stability, which not only endanger the safety of wellbore operation, but also seriously affect the safety of life and property of people in mining area. Therefore, it is urgent to solve the environmental impact and stability caused by gangue mountain in China. Aiming at the representative gangue mountain in Chongqing area, taking the gangue mountain of a coal mine in Chongqing as the research background, on the basis of field test and large triaxial test of coarse grained soil in the laboratory, the weathering strength characteristics of gangue are analyzed from the weathering characteristics of gangue. The limit analysis upper limit method and unbalanced thrust method are used to analyze the stability of gangue mountain, and the numerical simulation of the stability of gangue mountain is carried out. The gradation of new gangue and weathered gangue in a coal mine in Chongqing was determined, and the new gangue was separated into the same gradation as weathered gangue. The natural moisture content, saturated moisture content and different confining pressure were used as control conditions. Then the mechanical properties of two kinds of coal gangue were studied and compared through the large-scale triaxial test of coarse grained soil in laboratory. The mechanical properties of the triaxial strength of the new gangue and weathered gangue are compared and analyzed. The unbalanced thrust method is used to calculate the slope stability of a coal mine gangue mountain in Chongqing. At the same time, the slip instability mode in the gangue mountain is analyzed. On the basis of analyzing the mechanical properties of coal gangue, the corresponding molar-Coulomb constitutive relation and failure criterion are adopted, and the limit analysis upper limit method is established to analyze the stability of coal gangue mountain in a certain coal mine in Chongqing. The stability of gangue mountain in a coal mine in Chongqing was simulated by FLAC, and the stability of gangue gangue mountain in Chongqing and its influencing factors were discussed.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU45

【相似文献】