随着煤层深度及开采强度的增加，深井开采强矿压现象突显，严重威胁矿井安全高效生产。华亭矿区砚北煤矿采用综放开采，开采厚度为12.0m，论文以砚北煤矿强矿压为研究背景，应用关键层理论、物理相似材料模拟、数值模拟、岩石力学、材料力学、弹性力学等理论及研究手段，分析研究砚北煤矿综放开采覆岩结构失稳演化规律及其强矿压形成机理，确定综放工作面宽度和区段煤柱宽度与复合关键层控制范围之间的关系，选取合理的工作面宽度及区段煤柱宽度以达到避灾目的。主要研究结果如下： 华亭矿区砚北煤矿煤5层开采覆岩具有“两硬一软”特征。综合分析煤5层开采覆岩岩性特征及矿压显现情况表明：煤层顶板侏罗统地层中岩性较硬、分层厚度较大的砂岩分布较多，具有明显的关键层特性；侏罗统之上新近系甘肃群岩层以泥岩类为主，夹砂岩、砂砾岩，为强风化带，其与第四系黄土层组成覆岩上部松散加载层，总厚度180m左右。应用关键层理论计算分析砚北煤矿开采煤层覆岩特性，得出距煤5层顶板21.8m的位置19.8m厚的细砂岩为覆岩中的亚关键层，也是开采煤层的老顶；位于覆岩中部的两层厚度分别为20.19m和19.20m相邻的细砂岩和粉砂岩为覆岩中的主（复合）关键层，即覆岩移动变形的主控制层。华亭矿区砚北煤矿覆岩具有明显的“两硬一软”特征，两硬指较坚硬的亚关键层和坚硬的复合关键层，一软指覆岩上部到地表的厚松散层。 构造应力是强矿压形成的条件之一。通过物理相似材料模拟研究，结合矿井生产实践得出砚北煤矿长壁综放工作面初次来压步距为70~78m，周期来压步距为26~42m。水平构造应力对复合关键层破断步距存在一定影响，存在构造应力时复合关键层的破断步距大于非构造应力时破断步距，同时构造应力的作用使得复合关键层破断瞬间释放更大弹性能，使得工作面矿压显现更为剧烈。 覆岩中部复合关键层与其上方的应力拱构成控制覆岩破断失稳的大结构。相似材料模拟和数值模拟结果表明，煤5层综放开采条件下，亚关键层位于冒落带范围，随工作面开采产生初次破断和周期破断，不具备大范围控制能力和高强度致灾条件；复合关键层位于覆岩中部，具备大范围控制其上覆岩层运移的条件，其上覆岩层在运移过程中构成应力拱结构，当复合关键层破断应力拱结构失稳后，在其上覆岩层及厚松散层与其同步运动，释放巨大动载能量进而导致采掘场形成强矿压。 应用薄板理论构建了砚北煤矿复合关键层破断力学模型，结合实验模拟结果，分析了覆岩移动破坏演化规律及强矿压形成机理。在研究覆岩中部复合关键层和其上部软弱岩层及松散加载层构成的覆岩高位结构的基础上，应用薄板理论构建了复合关键层破断力学模型，在复合关键层破断步距计算公式中加入区段煤柱宽度的影响因子。经计算给出复合关键层破断时控制范围，为确定合理工作面宽度、区段煤柱宽度奠定了理论基础。通过理论分析给出，华亭矿区砚北煤矿煤5层开采覆岩中部复合关键层破断瞬间释放的冲击载荷是强矿压形成的主要条件，复合关键层控制范围越大，其破断前所承载的载荷和聚积的能量也越大，破断时形成的强矿压危害也越大。 应用数值模拟方法研究了工作面宽度和区段煤柱尺寸对强矿压灾害强度的影响，确定了区段煤矿宽度与复合关键层破断步距之间的关系。研究结果表明，在工作面宽度一定时，区段煤柱宽度越大，复合关键层控制覆岩范围越大，破断时释放弹性能越大，对井下安全危害也越大；区段煤柱宽度一定的条件下，在极限跨距内随着工作面宽度的增加，复合关键层控制覆岩范围增大，发生破断时释放弹性能增大，对井下安全威胁也加大。有效削弱区段煤柱支撑作用，减小复合关键层控制范围是减轻井下强矿压冲击威胁程度的重要途径之一，在华亭矿区砚北煤矿特定地质采矿条件下，合理工作面布置参数为：工作面宽度在140~150m左右，区段煤柱宽度不大于6m。

With the increase of depth of coal seam, deep mining strong pressure phenomenon is highlighted, serious threat to mine safety and efficient production.Study on Huating mining area Yanbei coal mining, key stratum theory, physics similar material simulation, numerical simulation, rock mechanics, material mechanics and elastic mechanics are used in this study. Analysis overburden structure fracture evolution process and mechanism of formation of strong pressure in Yanbei coal mining fully mechanized sub-level caving mining.Given the inclined length of face and coal pillar width,which related to composite key stratum control range in fully mechanized sub-level caving mining, chosing the suitable inclined length of face and coal pillar width to avoid the disaster. The major finding of the study as follows: Huating mining of the coal 5th layer stratum has the characteristic of “ two hard and one soft ” types. Comprehensive analysing the Huating mining of the coal 5th layer overburden rock lithology and structure and mine pressure behavior shows that the coal seam roof of Jurassic lithology has obvious control layer characteristic which is hard and has many large thickness sandstones.On the Jurassic upper tertiary strata Gansu group class-based mudstone, sandstone and conglomerate, as strong weathering zone, with the upper overlying Quaternary soil layer constitute the loose rock loading, which total thickness is about 180m. Using the key stratum theory to analyse Yanbei Mining overburden characteristic, to get the coal 5th layer upper 21.8m has a 19.8m thick sandstone rock as the sub-key stratum, also the coal seam main roof; the sandstone and siltstone rock which located two thickness of 20.19m and 19.20m adjacent as the main (composite) key stratum that controls a wide range of overlying strata movement and deformation. Huating Coal Yanbei Mining overburden has obvious feature of "two hard and one soft" , two hard layers are coal seam main roof and composite key stratum, one soft finger-thick layer of loose rock overlying the upper to the surface, which plays the main loading effect. Horizonta tectonic stress is one of the conditions of strong pressure formation. By physical similar material simulation, combined with the mine production practice that the Yanbei longwall fully mechanized sub-level caving mining face first pressure step distance is 70~78m, periodic pressure step distance is 26~42m. Horizontal tectonic stress has a certain influence in key stratum first breaking step. When exist horizontal tectonic stress the breaking step is bigger than inexistence horizontal tectonic stress, The effect of horizontal tectonic stress is make the key stratum breaking instantly face mine pressure appear more dramatic. Composite key stratum in middle overlying rock become a big structure to control overlying strata movement and failure in the overlying rock movement. Similar material simulation and numerical simulation result shows that, when used fully mechanized sub-level caving mining in coal 5th layer, sub-key stratum (main roof) is located in the caving zone, the initial fracture and fracture cycle with the working face, which does not have the ability to control a wide range and the condition of high strength disaster; While the composite key layer which located overlying the central rock, with its wide range of control overburden conditions, and its thick loose overburden layer , constitute squeeze arch large structure. When the key stratum breaking and arch structure instability, at the load of the weight of overburden rock and thick soil layer, releasing tremendous energy dynamic load which led mining field generating strong pressure mine disasters. Application of the theory of thin plate constructed Yanbei Mine key stratum breaking mechanical model, combined with the simulation experimental results, analyze the overburden damage movement evolution rule and formation disaster mechanism. Key stratum and its upper soft rock constitute large structure which control layer overlying movement and strong ground pressure, application of the theory of plate constructed key stratum breaking mechanical model, by theoretical calculation gives the key stratum first breaking and the cycle breaking control range for determining reasonable working face width, the width of coal pillars laid a theoretical foundation. Through theoretical analysis gives Huating coal mine overburden coal 5th layer composite key stratum breaking moment of release impact load is the main condition for the strong ground pressure, the greater the key stratum control, the load before the breaking load and accumulated energy is, the greater the -formative when breaking strength. Using numerical simulation method study on the effect of the face width and width of coal pillars for strong pressure mine disaster strength. The result shows that the face width fixed, the larger the width of coal pillars, the greater range of the key stratum control, the larger the control range of overlying strata, the greater the release of dynamic load at break, the greater the harm to the safety; under certain width of the coal pillar, with the increase in the limit spans the width of the working face, the key stratum control range is increased, the release of dynamic load occurs when breaking energy increases, the greater threats to security ; effectively weaken pillar supporting, reducing the key stratum control range is an important way to reduce the strong pressure threat at Huating coal mining Yanbei specific geological and mining condition, the optimum layout parameters face as follows: face width of 140~150m, section coal pillar width is not more than 6 m.