8.8 m超大采高综采工作面一次开采高度及开采强度大.采场围岩控制困难.采用立柱压力传感器.位移传感器对工作面回采期间支架工作阻力.顶板下沉量进行了全程系统监测.对工作面矿压显现规律.支架工作阻力循环曲线.顶板下沉量及割煤循环内下沉曲线进行了分析.对支架工作阻力.初撑力.支架刚度与顶板下沉关系进行了研究.研究结果表明:超大采高工作面开采具有来压区域性明显.来压急增阻.非来压恒阻.大小周期来压的宏观特征,工作面顶板下沉具有明显的时空差异性.空间上呈现工作面[两端小-中部大"的特征.时间上呈现来压期间大.非来压期间小的特点,工作面支架ΔF-T和顶板下沉ΔS-T均化循环曲线具有高度的一致性.来压期间2者均呈对数-大斜率线性复合增长.非来压期间呈现近常数或小斜率线性增长,顶板下沉与支架工作阻力呈线性对应关系.随支架工作阻力的增加而增大.安全阀开启后.顶板下沉速度明显增大.最大下沉速度为安全阀开启前的4.3倍.安全阀长时开启时顶板下沉速度由急增逐渐过渡至缓增状态.ZY26000/40/88液压支架在来压期间一定时间内可以将顶板下沉控制在一定的范围内.但并不能阻止其继续下沉,初撑力及支架刚度大小对顶板控制影响较为明显.随着初撑力的不断增大.顶板下沉及下沉速度显著降低并趋于稳定.临界点为15 MN.顶板下沉与支架刚度呈现类双曲线关系.支架刚度达到14 MPa/m以上时.支架刚度对顶板下沉的抑制作用减弱.顶板下沉趋于平稳状态.

It is difficult to control the surrounding rock of 8.8 m super high mining face because of its high mining height and high mining intensity.The column pressure sensor and displacement sensor are used to monitor the support working resistance and roof subsidence in the whole mining process,and this paper analyzes the law of mine pressure behavior,working resistance cycle curve of support,roof subsidence and coal cutting cycle subsidence curve,and studies the relationship between working resistance,initial support force,support stiffness and roof subsidence.The research results show that the working face with super large mining height has the macro characteristics of obvious regional pressure,rapid increase of resistance,constant resistance of non pressure,and large and small periodic pressure.The roof subsidence of working face has obvious space-time difference,showing the characteristics of [low at both ends-high in the middle" in space,showing the characteristics of large roof subsidence during weighting period and small roof subsidence during non weighting period in time.The support working resistance ΔF-T and roof subsidence ΔS-T homogenization cycle curves of working face are highly consistent,they both show logarithmic large slope linear compound growth during weighting period,and nearly constant or small slope linear growth during non weighting period.There is a linear relationship between roof subsidence and support working resistance,which increases with the increase of support working resistance.When the safety valve is opened for a long time,the roof subsidence speed gradually transits from rapid increase to slow increase.At present,the ZY26000/40/88 hydraulic support can control the roof subsidence within a certain range during a certain period of pressure,but it can not prevent it from sinking further.The roof control effect shown by the support force and the rigidity of the support is particularly obvious.With the increasing of the initial support force,the roof subsidence and subsidence speed decrease significantly and tend to be stable,and the critical point is 15 MN.The relationship between roof subsidence and support stiffness is hyperbolic.When the support stiffness reaches 14 MPa/m,the inhibition of support stiffness on roof subsidence is weakened,and the roof subsidence tends to be stable.

1 矿井及工作面条件

2 超大采高工作面支架工作阻力分析

   2.1 工作面矿压显现规律

   2.2 超大采高工作面支架工作阻力均化规律特征

3 超大采高工作面顶板下沉量分析

   3.1 ZY26000/40/88支架刚度分布特征

   3.2 工作面顶板下沉量

4 超大采高支架与围岩相互作用关系

   4.1 支架工作阻力与顶板下沉量关系

   4.2 初撑力与顶板下沉关系分析

   4.3 支架刚度与顶板下沉关系

5 结论