CAJ | 학술논문

对岩石-混凝土界面试件进行了轴向拉伸和三点弯曲梁试验，研究粗糙度对界面断裂特性的影响，建立了界面软化本构关系。以界面粗糙度为参量，结合界面三点弯曲试验所得的荷载-位移曲线，采用改进的J积分法计算裂缝扩展的能量损耗，建立了基于虚拟裂缝黏聚力能量守恒关系。通过归一化拟合建立的挠度、裂缝张开宽度及裂缝扩展长度关系，最终确定了岩石-混凝土界面的拉伸软化本构曲线，并提出指数型和双线型的黏聚力表达式。试验和计算结果表明：岩石-混凝土界面单轴抗拉强度、断裂韧度及断裂能随着界面粗糙度的增加而增大。本文所得的界面软化本构关系只与界面抗拉强度和断裂能有关，可以应用于不同粗糙度界面的断裂计算中。
대암석-혼응토계면시건진행료축향랍신화삼점만곡량시험，연구조조도대계면단렬특성적영향，건립료계면연화본구관계。이계면조조도위삼량，결합계면삼점만곡시험소득적하재-위이곡선，채용개진적J적분법계산렬봉확전적능량손모，건립료기우허의렬봉점취력능량수항관계。통과귀일화의합건립적뇨도、렬봉장개관도급렬봉확전장도관계，최종학정료암석-혼응토계면적랍신연화본구곡선，병제출지수형화쌍선형적점취력표체식。시험화계산결과표명：암석-혼응토계면단축항랍강도、단렬인도급단렬능수착계면조조도적증가이증대。본문소득적계면연화본구관계지여계면항랍강도화단렬능유관，가이응용우불동조조도계면적단렬계산중。
Laboratory tests, including uniaxial tension and three-point bending, were conducted on rock-concrete composite specimens to investigate the effect of interface roughness on interface fracture be?havior and to establish interfacial softening constitutive relation for various degrees of interface roughness. Based on the load-displacement curves measured in three-point bending tests, the energy dissipation can be derived through modified J-integral method. The energy balance during crack propagation can be estab?lished, i.e. the energy dissipation is equal to the energy caused by fictitious cohesive force acting on frac?ture process zone. Using the results of δ, w and a from experiment, which are normalized by the maxi?mum and fitted values, tension softening constitutive expression of rock-concrete interface model has been obtained. Experimental and calculated results indicate tensile strength, fracture toughness and fracture ener?gy of rock-concrete interface increase with the increase of interface roughness. Meanwhile, the expression of interfacial softening constitutive curve can be determined through measuring two parameters, i.e., inter?face tensile strength and interface fracture energy, which can be applied on fracture analysis of rock-con?crete interface with various roughnesses.