缓倾斜薄煤层机采方式的模糊识别

讨论了在设备选择不受限制的条件下地质条件对机采方式选择的影响 .地质条件包括多项指标 ,这些指标中有些是难以定量描述的 ,具有模糊性 .在现场调查的基础上 ,分析了几种薄煤层采煤机的机采方式及适应条件 .建立了缓倾斜薄煤层机采方式的模糊识别模型 ,模型能借鉴工程技术人员的经验 ,根据开采条件选择合理的机采方式 .     

近距离倾斜薄煤层上行开采可行性分析

为安全有效地进行上行开采,根据华坪县思棉煤矿煤层赋存条件及开采现状,利用理论分析和数值模拟对其进行分析验证,研究其上行开采顶板的围岩运动规律,通过工程实践证明思棉煤矿上行开采经济上合理,技术上可行。     

红梅露天铁矿缓倾斜分层开采实践

针对红梅铁矿缓倾斜露天矿开采存在的因三角矿带开采带来的高贫化、高损失等技术难题,提出了缓倾斜分层开采工艺:开采分层的倾向、倾角与矿体倾向、倾角一致,沿矿体走向和倾向掘进开段沟,沿矿体走向和倾向同时推进开采。缓倾斜分层开采工艺避免了台阶式开采工作面上三角矿带导致的一系列开采难题,对降低采矿损失与贫化率有利,平均损失率、贫化率分别下降了2. 8%和4. 1%。     

爆力运搬理论在缓倾斜--倾斜中厚矿体开采中的应用

论述地下开采爆力运搬理论及其在某铜矿中的应用，对于缓倾斜及倾斜中厚矿体的开采，苦不采用高成本的底盘漏斗采矿法，就存在安全性差或出矿效果差等问题，采用爆力运搬的采矿方法是解决这一问题的有效途径，爆力运搬在某铜矿圆柱切矿法的应用表明，该方法不仅能够保证安全，而且采矿直接成本比电耙山矿的底盘漏斗采矿法降低57．4％。     

加密单枝模糊识别

为单枝模糊识别与信息加密理论，加密技术相互嫁接的一项研究，提出加密单枝模糊识别系统和它的一般概念。给出单枝模糊识别的局部加密，单枝模糊识别的整体加密，算法与应用。     

障碍物信息模糊识别的实用方法

针对移动机器人工作环境中障碍的特点和机器人导航与避障规划等任务的需要,应用模糊识别理论,研究从障碍的图象中提取和处理边缘信息的方法,提出了障碍边缘识别及障碍几何中心求取的实用方法．     

厚煤层分层开采工作面瓦斯流场分布规律研究

针对厚煤层分层开采工作面回采期间瓦斯涌出治理问题,采用数值模拟计算方法,通过建立采空区瓦斯流场分布的数学模型,对白芨沟矿井首分层0102102工作面回采期间瓦斯流场分布规律进行了研究。结果表明:走向方向上,从工作面往采空区深部,风流速度减小,瓦斯体积分数增大;倾斜方向上,工作面回风巷一侧瓦斯体积分数高于进风巷一侧瓦斯体积分数,工作面上隅角瓦斯容易积聚引起瓦斯超限;垂直方向上,从工作面底板往采空区顶板,瓦斯体积分数逐渐增大;在不采取其他措施前提下,首分层0102102工作面开采前期和后期工作面上隅角以及回风瓦斯均会超限。研究结果为该矿厚煤层分层开采工作面回采期间瓦斯综合治理提供了理论依据。     

Spontaneous caving and gob-side entry retaining of thin seam with large inclined angle

Based on the research method of combining simulation analysis with field testing by distinct element process UDEC, we have analyzed the roof deformation and failure laws and roadway support technology of gob-side entry retaining in a thin seam with a large inclined angle. The results show that during exploitation in seams with large inclined angle, rotational subsidence of the main roof under the gob area is small and can maintain balance, so there is no need to provide artificial permanent support resistance for the main roof near the upper side to control rotational subsidence. Obstructed by the dense scrap rail, waste rock from the immediate roof caving slides from the upper gob area to the lower area and fills it, which strikes a balance between the immediate roof under the goaf after it fractures into large pieces and filling waste rocks.     

Evolution of a mining induced fracture network in the overburden strata of an inclined coal seam

The geological conditions of the Pingdingshan coal mining group were used to construct a physical model used to study the distribution and evolution of mining induced cracks in the overburden strata. Digital graphics technology and fractal theory are introduced to characterize the distribution and growth of the mining induced fractures in the overburden strata of an inclined coal seam. A relationship between fractal dimension of the fracture network and the pressure in the overburden strata is suggested. Mining induced fractures spread dynamically to the mining face and up into the roof as the length of advance increases. Moreover, the fractal dimension of the fracture network increases with increased mining length, in general, but decreases during a period from overburden strata separation until the main roof collapses. It is a1so shown that overburden strata pressure plays an important role in the evolution of mining induced fractures and that the fractal dimension of the fractures increases with the pressure of the overburden.     

Analysis of stability of support and surrounding rock in mining top coal of inclined coal seam

The study analyzes the characteristics of roof movement in mining top coal of inclined coal seam, and establishes the mechanical model of support and surrounding-rock stability in inclined coal seam. Besides, this study carries out the numerical calculation and field observation of roof movement and support stability, and provides the critical control measures. The results show that the fracture firstly appears in middle-upper roof and extends upwards in top coal caving in inclined coal seam; regular and irregular caving zones appear in middle-upper stress concentration region, and the asymmetric caving arch is finally formed. Support load of middle-upper working face is larger than that of the middle-lower face; dynamic load coefficient of upper support is large, and the load on the front of support is larger than that on the rear of it, which leads to poor support stability. Stability of support and surrounding-rock system depends mainly on upper-support stability.     

坚硬顶板松软薄煤层刨煤机开采可刨性研究

依据目前国内外刨煤机开采实践,提出了煤层可刨性综合指标计算方法,将薄煤层可刨性划分为5类,即极易刨、易刨、一般、难刨和极难刨．根据曹窑煤矿坚硬顶板松软薄煤层地质条件和矿压显现规律,计算出薄煤层可刨性综合指标值,表明该薄煤层的可刨性属于一般类型．最后优化出了薄煤层刨煤机开采设备配套方案,为曹窑煤矿进行刨煤机开采提供了理论基础．     

Classification of conditions for short-wall continuous mechanical mining in shallowly buried coal seam with thin bedrock

The room and pillar method is usually used to extract coal from shallowly buried seams with thin bedrock. This results in a very low production efficiency and in a low degree of extraction. In recent years short-wall continuous mechanical mining has been extensively used in many situations except shallowly buried coal seams with thin bedrock. The principles governing movement of the overlying strata above the 2.<,2. coal seam were deduced from in-situ experience, laboratory data, calculations and computer simulations. The thicknesses of the bedrock in the Shendong Coal Field where the coal is shallowly buried are classified into 5 types: <10 m, 10-15 m, 15-25 m, 25-35 m and >35 m, which was done using fuzzy clustering results. A series of reasonable,relative parameters in each category have been calculated and analyzed. One proposed way to perform short-wall continuous mechanical mining in shallowly buried coal seams is given. This is significant for coal mines with similar geological conditions.     

Strata behavior investigation for high-intensity mining in the water-rich coal seam

This paper describes a specific case of mining in a water-rich coal seam in western China. Water inrushes, roof caving and other disasters induced by intensive mining operation could pose great threats to the safety of coal mines. The strata behavior during the high-intensity extraction in the water-rich coal seam is analyzed by employing the numerical simulation method and in situ monitoring. The results show that about 10 m ahead of the workface, the front abutment pressure peaks is at 34.13 MPa, while the peak of the side abutment pressure is located about 8 m away from the gateway with the value of 12.41 MPa; the height of the fracture zone, the first weighting step and the cycle weighting step are calculated to be 45, 50 and 20.8 m, respectively; pressure distribution in the workface is characterized by that the vertical pressure in the center occurs earlier and is stronger than those on both ends. Then, the results above are verified by in situ measurement, which may provide a basis for safe mining under similar conditions.     

Hydraulic support crushed mechanism for the shallow seam mining face under the roadway pillars of room mining goaf

While the fully-mechanized longwall mining technology was employed in a shallow seam under a room mining goaf and overlained by thin bedrock and thick loose sands, the roadway pillars in the abandoned room mining goaf were in a stress-concentrated state, which may cause abnormal roof weighting, violent ground pressure behaviours, even roof fall and hydraulic support crushed(HSC) accidents. In this case,longwall mining safety and efficiency were seriously challenged. Based on the HSC accidents occurred during the longwall mining of 3-1-2 seam, which locates under the intersection zone of roadway pillars in the room mining goaf of 3-1-1 seam, this paper employed ground rock mechanics to analyse the overlying strata structure movement rules and presented the main influence factors and determination methods for the hydraulic support working resistance. The FLAC3 D software was used to simulate the overlying strata stress and plastic zone distribution characteristics. Field observation was implemented to contrastively analyse the hydraulic support working resistance distribution rules under the roadway pillars in strike direction, normal room mining goaf, roadway pillars in dip direction and intersection zone of roadway pillars. The results indicate that the key strata break along with rotations and reactions of the coal pillars deliver a larger concentrated load to the hydraulic support under intersection zone of roadway pillars than other conditions. The ‘‘overburden strata-key strata-roadway pillars-immediate roof" integrated load has exceeded the yield load that leads to HSC accidents. Findings in HSC mechanism provide a reasonable basis for shallow seam mining, and have important significance for the implementation of safe and efficient mining.     

Key technologies and engineering practices for soft-rock protective seam mining

Severe gas disasters in deep mining areas are increasing, and traditional protective coal seam mining is facing significant challenges. This paper proposes an innovative technology using soft rock as the protective seam in the absence of an appropriate coal seam. Based on the geological engineering conditions of the new horizontal first mining area of Luling Coal Mine in Huaibei, China, the impacts of different mining parameters of the soft-rock protective seam on the pressure-relief effect of the protected coal seam were analyzed through numerical simulation. The unit stress of the protected coal seam, which was less than half of the primary rock stress, was used as the mining stress pressure-relief index. The optimized interlayer space was found to be 59 m for the first soft-rock working face, with a 2 m mining thickness and 105 m face length. The physicochemical characteristics of the orebody were analyzed, and a device selection framework for the soft-rock protective seam was developed. Optimal equipment for the working face was selected, including the fully-mechanized hydraulic support and coal cutter. A production technology that combined fully-mechanized and blasting-assisted soft-rock mining was developed. Engineering practices demonstrated that normal circulation operation can be achieved on the working face of the soft-rock protective seam, with an average advancement rate of 1.64 m/d. The maximum residual gas pressure and content, which were measured at the cut hole position of the protected coal seams (Nos. 8 and 9), decreased to 0.35 MPa and 4.87 m³/t, respectively. The results suggested that soft-rock protective seam mining can produce a significant gas-control effect.