【作者】 苗彦平；

【导师】 黄庆享；

【作者基本信息】 西安科技大学 ， 采矿工程， 2010， 硕士

【摘要】 神东矿区是我国最大的现代化能源基地，根据煤层赋存特点，一般采用一次采全高综合机械化方式开采，采高一般为5.0m，随着机械化程度的不断提高，部分工作面采高已达6.0m，补连塔煤矿22303工作面采高达7.0m。随之支架额定工作阻力不断增加，由3500kN、7592kN、10800kN、12000kN，到目前最大达16800kN，使大采高综采面成套设备费用不断增加，为了掌握其规律，论文综合运用现场实测、理论分析与计算及数值模拟等研究方法，以“张家峁煤矿试采工作面矿压规律及地表移动观测技术研究”等课题为依托，对神东矿区浅埋煤层大采高综采面由于采动影响上覆岩层垮落后形成的结构、矿压显现规律及合理的支护阻力进行了分析研究。研究认为：浅埋煤层大采高综采面矿压显现的突出特点是基岩沿架后全厚切落，直接波及至地表，上覆岩层为冒落带和裂隙带“两带”，来压期间顶板动载明显，老顶初次来压步距约54m，周期来压步距平均约15m，支架运转特性主要为一次增阻型，周期来压期间平均工作阻力达10799kN，来压强烈，持续时间短，中部测区有60%支架安全阀开启，来压期间中部测区支架工作阻力和动载系数大于两侧测区，说明工作面中部来压强烈。数值模拟与理论分析验证了，浅埋煤层大采高综采面顶板为单一关键层结构，顶板破断后不能形成稳定的“砌体梁”结构，关键块易出现架后滑落失稳，对“台阶岩梁”模型从另一种角度对关键块稳定性进行了分析，提出台阶下沉角，得出台阶下沉角与回转角之间的关系，并将其引入“台阶岩梁”阻力计算公式中。对关键块分析发现采高、直接顶厚度及关键块厚度及垮落长度是关键块台阶下沉角与台阶下沉量的影响因素，同时发现在相同赋存条件下，随着采高的增加，台阶下沉角也在增加。并用建立的台阶下沉角阻力计算公式计算相应大采高支护阻力与实测结果比较符合，同时发现，支架所承担的重量远小于上覆岩层全部重量，仍然存在明显的载荷传递效应，最后确定额定工作阻力为12000kN液压支架基本满足浅埋煤层大采高综采面控制顶板的要求，并且得到了现场实践的验证。通过研究，基本掌握了神东矿区浅埋煤层大采高综采面矿压显现规律，确定了合理的支护阻力，并对前人所提出的浅埋煤层定义进行了补充，为其他类似大采高综采工作面回采提供了科学的依据。更多还原

【Abstract】 Shendong Mining Area is the largest modern energy base in China. According to the coalseam characteristics the general mining method is fully-mechanized once mining all heightwithout local small coalpits, and the mining height is 5.0m. With the continuous improvementof mechanization part of the mining face height reaches 6.0m, which has reached 7.0m in22303 work face of Bu lian-ta coal. The support rated resistance increases continuously, from3500kN, 7592kN, 10800kN, 12000kN to the present largest 16800kN, which makes the costof complete fully-mechanized large mining height equipments increase. In order to master theregularity, the dissertation integrates the methods of field measurement, theoretical analysiscalculation and numerical simulation, and relying on some projects, such as "Technologyresearch on the pressure behavior principle and surface movement observation inexperimental mining face of Zhang Jia-mao coal.", it researches the structure formed byoverlying rock collapsing because of mining influence, the pressure behavior and reasonablesupport resistance.The results show that the prominent features of pressure behavior in fully-mechanizedlarge mining height work face of shallow seam are the bedrock cutting off along the shelf fullthickness, which directly affects to the surface, and the overlying should be divided "twozones": caving zone and fracture zone. During the roof weighting time the dynamic loadperforms significantly, whose first weighting interval is about 54m, and the average periodicweighting interval is about 15m. The operation character of shield hydraulic support is anincreased resistance. During the periodic weighting the average resistance reaches43MPa(10799kN), and the pressure performs strongly with short time. 60% supports haveopened safety valves in the middle survey area. Both resistance and dynamic load coefficient of support in middle are bigger than ones in two sides, which shows that the pressure performsintensively in middle of work face.Numerical simulation and theoretical analysis verify that the roof structure of shallowseam has a single key layer which can not form a stable "masonry beam" structure after roofbreaking, and the key block is prone to slide instability behind support. The dissertationanalyzes the stability of the block in "step voussoir beam" model from anther point. Itestablishes the step subsidence angle, finds out its relationship to the rotation angle, andintroduces it into the "step voussoir beam" resistance calculation equation. The analysis of thekey block indicates that the mining height, the immediate roof thickness, and the thickness andfalling length of the key block are influence factors of step subsidence angle and convergence.Meanwhile the analysis shows that the step subsidence angle increases as the mining heightincreasing under the same occurrence conditions. This dissertation calculates the large miningheight support resistance by using the established resistance calculation equation with stepsubsidence angle, which is basically consentaneous with practical results. Meanwhile, itshows that the support bearing weight is far less than the all overburden weight, and the loadtransfer-effect exists. Finally it determines 12000kN rated resistance support basically meetsthe requires of roof control in fully-mechanized large mining height work face of shallowseam, which is verified by field practice.Through research the dissertation basically graspes the principle of pressure behavior infully-mechanized large mining height work face of shallow seam in Shendong Mining Area,and determines reasonable support resistance. Moreover, it complements the previousdefinition of shallow beam, and provides scientific evidence for mining in other similar fullymechanizedwork face.更多还原