CAJ | 학술논문

依据非常规储层层状岩体的结构特点，根据相似原理制作不同材料、不同界面性质的层状岩体试件，通过三点弯曲试验发现裂缝经过异弹性材料界面后扩展转向，力学性能差异越大，界面强度越弱，裂缝转向角度越大。以试验参数为基础，建立了垂直裂缝扩展的平面应变模型，并获得了垂直裂缝经过砂/泥岩界面扩展过程中应力场，计算了裂缝尖端应力强度因子的变化规律，获得了裂缝偏转角度。通过计算发现：裂缝偏转是由界面的剪切应变增大而引起剪切应力强度因子增加，使得Ⅰ型裂缝经异弹界面而发展为Ⅰ—Ⅱ型复合裂缝引起的。
의거비상규저층층상암체적결구특점，근거상사원리제작불동재료、불동계면성질적층상암체시건，통과삼점만곡시험발현렬봉경과이탄성재료계면후확전전향，역학성능차이월대，계면강도월약，렬봉전향각도월대。이시험삼수위기출，건립료수직렬봉확전적평면응변모형，병획득료수직렬봉경과사/니암계면확전과정중응력장，계산료렬봉첨단응력강도인자적변화규률，획득료렬봉편전각도。통과계산발현：렬봉편전시유계면적전절응변증대이인기전절응력강도인자증가，사득Ⅰ형렬봉경이탄계면이발전위Ⅰ—Ⅱ형복합렬봉인기적。
According to the structural feature of unconventional reservoir stratified rock mass,stratified rock mass speci-mens of different materials and interface properties are manufactured on the basis of similarity principle.Veer extension after cracks cross different elastic material interface is found through the three point bending experiment,the more difference be-tween the mechanical properties,the weaker interfacial strength,and the larger steering angle the crack has.Based on the experiment parameter,a plane strain model of vertical crack propagation is established,the stress field of vertical crack via sand/shale interface in the process of the extension is obtained,the stress intensity factor variation of crack tip is calculated, and the angle of crack deflection is gained.The results of calculations show that the veer extension is caused by that theⅠtype crack turning toⅠ-Ⅱtype compound crack when the shear stress intensity factor increases because of the increasing interfacial shear strain.