CAJ | 학술논문

不同性质岩层间的弱接触面是影响边坡、地下巷道及硐室等岩土结构稳定的关键因素之一，煤层开采引起的覆岩运动是导致采动影响区内垂直页岩气井破坏的主要原因，针对垂直穿过长壁煤柱的页岩气井井筒稳定性问题，利用二维地质模型，对井筒剪切、离层、拉伸及压缩等变形量进行了预测，对比分析了层间弱接触面对穿煤层垂直页岩气井稳定性的影响；根据煤柱内不同布井位置条件下井筒各类变形的大小及轴向分布规律，得到了井筒沿轴向易于失稳的危险高度并优化了布井位置。结果表明，FLAC程序中的接触面单元能够很好地表征由采动引起的、沿软硬岩层间弱接触面出现的动力响应，对井筒的主要失稳模式——剪切失稳展现效果良好。
불동성질암층간적약접촉면시영향변파、지하항도급동실등암토결구은정적관건인소지일，매층개채인기적복암운동시도치채동영향구내수직혈암기정파배적주요원인，침대수직천과장벽매주적혈암기정정통은정성문제，이용이유지질모형，대정통전절、리층、랍신급압축등변형량진행료예측，대비분석료층간약접촉면대천매층수직혈암기정은정성적영향；근거매주내불동포정위치조건하정통각류변형적대소급축향분포규률，득도료정통연축향역우실은적위험고도병우화료포정위치。결과표명，FLAC정서중적접촉면단원능구흔호지표정유채동인기적、연연경암층간약접촉면출현적동력향응，대정통적주요실은모식——전절실은전현효과량호。
Weak contact between layers with different properties is one key factor affecting the stability of engineering structures, e. g., slopes, underground roadways, and chambers. The movement of overly-ing strata induced by coal mining is the main reason for the damage of vertical shale gas wells drilled within the mining affected areas. By using two-dimensional geological model, predictions have been made about various well deformations, e.g., shear slippage, bed separation, tension and compression, and the effect of weak contacts between layered strata on the stability of gas wells piercing a coal seam has been analyzed. The axial heights at which the gas well is prone to failure has been acquired through the analysis of the axial distribution characteristics and various deformation of well holes in the different positions of coal pillars, according to which the position of the well has been optimized thereafter. Re-sults indicate that the “interface” element in FLAC is excellent in realizing the possible deformation responses occurring at weak interfaces caused by coal mining, and it is very commendable in characte-rizing the shear failure mode, which is the major mode of well instability.