树脂锚杆锚固性能及影响因素分析

采用理论分析、实验室试验、数值模拟及井下实测相结合的方法对树脂锚杆锚固性能及影响因素进行研究。理论分析了锚杆在拉拔与全长锚固状态下的应力分布特征;在实验室进行了不同形状锚杆、不同钻孔直径下锚杆拉拔力试验,得出了锚杆形状、孔径差对锚杆拉拔力的影响程度;测试了不同模拟钻孔温度、淋水量下锚杆的拉拔力,得出了温度、淋水量与锚杆拉拔力之间的关系。采用有限差分数值模拟软件FLAC3D,计算了不同杆体形状、孔径差、居中度及不同围岩强度下锚固剂、围岩中的剪应力大小,分析了诸因素对剪应力分布的影响,得出了不同条件下剪应力分布特征。在平庄风水沟煤矿井下进行了软岩可锚性试验,实测了软岩不同含水状态下锚杆、锚索拉拔力。最后,提出改进树脂锚杆锚固性能、提高锚固力的建议。

Analysis on anchorage performances and affecting factors of resin bolts

The anchorage performances and affecting factors of resin bolts were studied by the combination method of theoretical analysis，laboratory tests，numerical modeling and field measurement.The stress distribution along bolts in pullout and fully anchored states was theoretically analyzed；the pullout tests of bolts with different profiles and anchored in boreholes with various diameter were carried out in laboratory，and the affecting degree of bolt profiles and diameter difference between bolts and boreholes to the bolt pullout force was obtained；the pullout force of bolts anchored in simulated boreholes with different temperature and water dripping content was measured，and the relations between pullout force and temperature，water dripping content were got.By means of FLAC3D，the shear stresses in resin and surrounding rock along bolts with different profiles，resin annulus thickness，concentricity，and anchored in rocks of different strength were calculated，the affecting of these factors to shear stress distribution was analyzed，and stress distribution features were obtained.The soft rock anchorage test was carried out in underground，in the Fengshuigou Coal Mine，the Pingzhuang coal mining district，and the pullout loads of bolts and cables in soft rock with different water content were measured.Finally，the suggestions for improving resin anchorage performances and enhancing anchorage force were put forward.