深孔预裂爆破注浆封孔材料力学特性实验

针对深孔预裂爆破注浆封孔材料配比选择问题,以水泥、速凝剂、水为注浆原料,开展不同材料配比、不同养护时间的单轴抗压强度实验,分析封孔长度与材料力学特性的关系。结果表明:不同配比深孔预裂爆破注浆材料的抗压强度范围为0.60~4.49MPa,最大弹性模量为0.527GPa;注浆材料的抗压强度和弹性模量与水灰比呈负相关关系,与速凝剂和水泥的比例(A/C)呈正相关关系;同一配比条件下,注浆材料抗压强度随养护时间增加而增大,6h后趋于平稳。计算得出封孔长度与材料抗压强度、侧压系数呈负相关关系。综合实验及分析得出,深孔预裂爆破施工中可选用水泥、速凝剂、水为1∶1∶1的比例配比封孔,封孔后养护6h放炮。

Experimental Study of Mechanical Properties for Grouted Sealing Material in Deep Hole Pre-Splitting Blasting

Aiming at the selection of grouted sealing material ratio in deep hole pre-splitting blasting,taking cement,quick setting agent and water as grouting material,uniaxial compression strength experiment was carried out by adopting different material ratios and different curing time durations,the relations among hole sealing length and material mechanical properties were analyzed.Results show that the compression strength of grouting material with different ratios in deep hole pre-splitting blasting is in a range from 0.60MPa to 4.49MPa,and the maximum elastic modulus is 0.527GPa.Compression strength and elastic modulus of grouting material is negatively correlated with watercement ratio,and positively related to quick setting agent-cement (A/C) ratio.Under the same material ratio condition,the compression strength of grouting material increases with the increase of curing time,and tends to be stable after 6 hours.Calculation shows that there are negative relations among sealing length and material compression strength and lateral pressure coefficient.Combining experimental and calculation results,the best ratio of cement,quick setting agent and water is 1 ∶ 1 ∶1 for deep hole pre-splitting blasting grouted sealing material.Blasting should be arranged after 6 hours curing time.