双河煤矿采动巷道顶板裂隙的分形研究

巷道顶板的变形量是评价巷道顶板稳定性的一个重要指标,巷道顶板裂隙的间距分形维是综合反映顶板裂隙发育、分布特征的一个重要参数,尝试建立二者之间的数学关系。利用多基点位移计对双河煤矿采动巷道顶板的变形量进行了监测,利用钻孔电视成像仪对顶板内裂隙的发育和分布状况进行了监测,并且计算出顶板内裂隙间距的分形维。结果表明,顶板0~2 m内裂隙最为发育,在此范围内,裂隙线密度与裂隙间距分形维具有相同的变化趋势,二者具有线性关系;顶板的变形量与相应的裂隙间距分形维具有相同的变化趋势,顶板裂隙的间距分形维增大,相应的围岩变形量增大,二者之间存在线性关系。研究结果表明,顶板裂隙的间距分形维是综合反映巷道顶板稳定性的一个指标,可以作为巷道顶板稳定性的指标,对巷道顶板稳定性进行评价,为支护设计提供可靠依据。

基于FLAC^(3D)采动巷道围岩支护参数优化分析

183下03胶顺顶板为泥岩,受采动影响,顶板极易破碎,为了提高巷道的支护强度,需要对原锚网索支护参数进行优化。通过布置不同锚杆密度、锚索长度,设计了5种支护方案,采用FLAC^(3D)模拟5种方案支护情况下巷道围岩应力和位移变化情况,得到锚杆支护越密、支护强度越高,顶板变形量越小;锚索支护越短,顶板变形量越小。结合矿井的经济效益,确定锚网索支护最合理参数。通过监测顶板变形量可知,优化参数后支护强度明显提高,在动压影响下能够保证巷道安全。

Prediction of representative deformation modulus of longwall panel roof rock strata using Mamdani fuzzy system

Deformation modulus is the important parameter in stability analysis of tunnels, dams and mining struc- tures. In this paper, two predictive models including Mamdani fuzzy system （MFS） and multivariable regression analysis （MVRA） were developed to predict deformation modulus based on data obtained from dilatometer tests carried out in Bakhtiary dam site and additional data collected from longwall coal mines. Models inputs were considered to be rock quality designation, overburden height, weathering, unconfined compressive strength, bedding inclination to core axis, joint roughness coefficient and fill thickness. To control the models performance, calculating indices such as root mean square error （RMSE）, variance account for （VAF） and determination coefficient （R^2） were used. The MFS results show the significant prediction accuracy along with high performance compared to MVRA results. Finally, the sensitivity analysis of MFS results shows that the most and the least effective parameters on deformation modulus are weatherin~ and overburden height, respectively.