1．School of Coal Engineering，Shanxi Datong University，Datong ，China;
2．School of Ｒesources and Saftey Engineering，China University of Mining and Technology( Beijing) ，Beijing ，China

为准确分析瓦斯抽采钻孔周围应力分布及卸压范围,建立了基于Hoek-Brown准则的瓦斯抽采钻孔软化及扩容力学模型,推导了孔周弹性区、塑性软化区和破碎区应力计算过程;并对比分析了未考虑煤体塑性软化及扩容特性情况下孔周应力分布情况,考虑煤体软化及扩容时孔周卸压及塑性区范围均有所增大。在霍尔辛赫煤矿试验了水力喷射压裂技术,并利用所建立的瓦斯抽采钻孔软化及扩容力学模型分析试验后孔周卸压及塑性区范围,结果表明:卸压及塑性区范围增大1倍多;抽采影响范围增大,达到了卸压增透的效果;并对比常规钻孔抽采参数,水力喷射压裂钻孔抽采浓度及日抽采纯量随时间衰减变缓,抽采效果得到改善。

In order to accurately analyze the surrounding stress distribution and pressure released scope of the gas drainage borehole，with the water bole was a case，a softening and volume expansion mechanics model of the gas drainage borehole was established based on the Hoek－Brown Criterion and the stress theoretical calculation process of the borehole surrounding elastic zone，plastic softening zone and broken zone was inferred． A COMSOL software was applied to analyze the stress distribution surrounded along the borehole without a con- sideration of the coal plastic softening and volume expansion features． The pressure released and plastic zone scope surrounded along the borehole increased was considered when the coal was softened and expanded． In Huoerxinhe Mine，the hydraulic fracturing technology was tested and the mechanics model of the gas drainage borehole was applied to analyze the pressure released and plastic zone scope surroun- ded along the borehole after the test． The results showed that the pressure released and plastic zone scope was increased over 2 times． The gas drainage influence scope was increased and reached at the pressure released and permeability improved effect． In comparison with the conventional gas drainage parameters of the borehole，the gas drainage concentration from the hydraulic fractured borehole and the daily drainage pure volume would be slow with the time decayed and the gas drainage effect was improved．

国家自然科学基金资助项目(51404093)；山西大同大学青年基金资助项目(2016Q12)；