为了揭示煤层瓦斯抽采钻孔失稳破坏规律及服役寿命周期特征，研发了包括钻孔变形模拟装置和钻孔变形测试装置的钻孔变形破坏测试系统，利用相似材料进行了钻孔变形破坏全过程的试验测试。研究了压力感应器压力、钻孔变形之间的关系，提出了评价钻孔变形破坏状态的指标——钻孔破坏度。基于试验测试数据建立了钻孔破坏度与压力感应器压力的定性关系，根据试验结果确定了钻孔塌孔失效的判定条件为钻孔破坏度大于50%。现场测试了瓦斯抽采钻孔的变形破坏过程，分析了钻孔破坏度随时间和孔深的变化规律，定量考察了钻孔稳定性，发现钻孔成孔后初期变形破坏速度较快，之后进入缓慢变形破坏阶段直至稳定;沿孔深方向，钻孔破坏度先增大后减小，孔深5～11m范围内钻孔破坏度最大，与巷道围岩应力分布相吻合，对确定合理封孔深度有指导意义;钻孔的变形破坏对瓦斯抽采流量影响显著，随着钻孔破坏度增加至50%及以上，钻孔失效，无法继续抽采。研究成果对合理瓦斯抽采设计、瓦斯抽采动态考察、准确评价抽采效果提供了依据。

In order to reveal the instability and failure rules of coal seam gas drainage and the characteristics of its service life cycle,the drilling deformation and fai lure testing system that includes the drilling deformation simulation device and the drilling deformation testing device was developed,and the whole process of borehole deformation and failure was tested by using similar materials. The relationship between the pressure of the pressure sensor and the borehole deformation was studied, and the index of borehole damage degree is proposed to evaluate the deformation and failure state of boreholes. Based on the test data,the qualitative relationship bet ween the borehole failure degree and the pressure of the pressure sensor was established. According to the test results,the borehole collapse was determined to be gre ater than 50%. The deformation and failure process of gas drainage boreholes was tested on site,and the variation law of borehole damage degree with time and boreh ole depth was analyzed,and the borehole stability was quantitatively investigated. It was found that the initial deformation failure rate was fast and the degree was larg e,and then entered the stage of slow deformation and failure until it stabilized;along the direction of borehole depth,the damage degree of borehole first increased and t hen decreased,the damage degree of borehole was the largest in the range of 5 ~ 11 m,which was consistent with the stress distribution of surrounding rock around th e roadway,and it was of guiding significance for determining the reasonable sealing depth. The deformation and failure of the borehole has a significant impact on the g as drainage flow. As the damage of the borehole increases to 50% and above,the borehole fails,and the gas drainage cannot be continued. The research results provid e a basis for reasonable gas drainage design,gas drainage dynamic investigation and accurate evaluation of drainage effect.