【摘要】 为研究预制裂隙长度对不同岩石材料抗拉性能及裂隙变形特性的影响，选择花岗岩、中砂岩、石灰岩3种典型脆性岩石制备了直切槽半圆盘弯曲(notched semi-circular bend, NSCB)试样并进行了加载试验，采用数字散斑相关法(digital image correlation, DIC)监测了试样破坏过程中的变形。结果表明：岩石试样的断裂韧度与抗压、抗拉强度及弹性模量等力学参数成正相关，NSCB试样的承载能力与已存在的裂缝长度成负相关；当裂纹长度超过一定值(a≥3 mm)时，NSCB试样的承载力与裂纹长度成负指数关系；NSCB试样的变形特性受岩石晶体结构和微裂纹分布的影响显著，岩石矿物质的胶结程度越高，结构越致密，微裂隙不发育，则起裂应力高，破坏前的变形程度较小，反之亦然。研究结果为进一步认识岩石材料裂隙扩展机理及预测其扩展范围提供了依据。更多还原

【Abstract】 In order to study the influence of prefabricated fracture length on the tensile properties and fracture deformation characteristics of different rock materials, notched semi-circular bend(NSCB) specimens of three typical brittle rocks, including granite, medium sandstone and limestone, were selected for loading tests. The deformation of the specimen during failure was monitored by digital image correlation(DIC). The results show that the fracture toughness of rock specimens is positively correlated with mechanical parameters such as compressive strength, tensile strength and elastic modulus, and the bearing capacity of NSCB specimen is negatively correlated with the length of existing cracks. When the fracture length exceeds a certain value(a≥3 mm), the bearing capacity of NSCB specimen has a negative exponential relationship with the fracture length. The deformation characteristics of NSCB specimens are significantly affected by the crystal structure and micro-crack distribution of rock. The higher the degree of cementation of rock minerals, the denser the rock crystal structure, the less developed the micro-cracks, the higher the fracture initiation stress, and the smaller the deformation degree before failure, and vice versa. The research results can provide a basis for further understanding the fracture propagation mechanism of rock materials and predicting its expansion range.更多还原