CAJ | 학술논문

根据节理岩体切向加载作用下的变形机制,把微凸体在磨损破坏过程中引起的剪胀软化现象和伴随的强化现象分开考虑,提出一种新的本构模型.试验结果表明,在法向和切向载荷共同作用下,由于微凸体的爬坡和啃断作用,节理岩体均会发生一定程度的剪胀和磨损,累积到一定程度就产生软化现象,在此引入一个初始剪应力概念体现上述特征.另一方面,由于破碎颗粒的碾压和迁移作用,使得抗剪力学行为由微凸体粗糙度控制逐渐转变为由结构面上形成的紧密夹层的力学行为所控制,抗剪强度提高,在此通过弹塑性随动强化模型来体现这一变形行为.当随动强化模型与初始剪应力相结合时,即为节理岩体切向加载作用下的剪应力–切向位移本构关系.通过对各种已有试验曲线的对比分析,验证该模型的正确性.
근거절리암체절향가재작용하적변형궤제,파미철체재마손파배과정중인기적전창연화현상화반수적강화현상분개고필,제출일충신적본구모형.시험결과표명,재법향화절향재하공동작용하,유우미철체적파파화습단작용,절리암체균회발생일정정도적전창화마손,루적도일정정도취산생연화현상,재차인입일개초시전응력개념체현상술특정.령일방면,유우파쇄과립적년압화천이작용,사득항전역학행위유미철체조조도공제축점전변위유결구면상형성적긴밀협층적역학행위소공제,항전강도제고,재차통과탄소성수동강화모형래체현저일변형행위.당수동강화모형여초시전응력상결합시,즉위절리암체절향가재작용하적전응력–절향위이본구관계.통과대각충이유시험곡선적대비분석,험증해모형적정학성.
Based on the failure mechanism of jointed rock mass under shear loading,a new constitutive model is presented;the essence of which is dilatancy softening phenomenon and strengthening phenomenon that should be considered separately when asperity surface will undergo the wearing,grinding and crushing. From many direct shear tests,it is concluded that the jointed rock mass will generate dilatancy and wear as the behavior of overriding and shearing for asperity surface under normal and shear loadings. When damage is accumulated to a certain extent,it will result in softening. A new concept of initial shear stress is introduced to reflect the above characteristics. On the other hand,as the motion of broken granules,the mechanical behavior of shear which is controlled by asperities will gradually transform to compact controlled layer;and it makes shear strength increase. This microscopic change effects are described by considering elastoplastic kinematic hardening model. The constitutive equations are derived with combining kinematic hardening model and initial shear stress. The validity of proposed constitutive model is verified through applications to several existing laboratory test results on intact and artificial jointed rocks.