含层理灰岩巴西劈裂强度及拉裂损伤各向异性

为了研究不同角度层理对灰岩抗拉力学特性的影响，对7组不同角度层理灰岩进行巴西劈裂试验，根据岩石声发射累计振铃次数定义拉裂损伤变量，推导抗拉强度、劈裂模量及损伤变量随层理角度的变化规律。研究结果表明，(1)不同层理角度的灰岩，其受力变形过程基本一致，即经历压密、弹性和破坏3个阶段。(2)抗拉强度、拉伸模量随层理角度变化表现出明显的各向异性，在0°时最大，90°时最小。(3)基于岩体微元强符合Weibull分布及Lemaitre应变等效原理，通过拟合计算得到的损伤参数可以较好地反映7个角度灰岩样的损伤特性，损伤变量也具有各向异性特点，说明不同倾角的岩石参数在加载过程中有不同的劣化程度，同一应变水平下的损伤变量随着层理角度的增加出现下降的趋势。研究结果对于层状灰岩的试验研究、理论计算和工程建设具有一定的指导意义。

Research on Brazilian Splitting Strength and Tensile Damage Anisotropy of Laminated Limestone

In order to study the influence of different bedding angles on the tensile mechanical properties of limestone, Brazilian tensile test was carried out on 7 sets of different angles of limestone samples. The tensile damage variables were defined according to the cumulative times of the acoustic emission signals (the AE signals), and the tensile strength was derived. The results show that (1) the limestone with different bedding angles is basically consistent in the process of stress deformation, that is, it has three stages of compaction, elasticity and destruction. (2) The tensile strength and tensile modulus show obvious anisotropy with the change of the bedding angles, which is the largest at 0° and the smallest at 90°. (3) Based on the Weibull distribution and the Lemaitre strain equivalence principle, the damage parameters obtained by fitting calculation can better reflect the damage characteristics of the limestone samples, and the damage variables also show anisotropy. Results show that the rock parameters with different bedding angles have different degrees of deterioration during the loading process, and the damage variables at the same strain level decrease with the increase of the bedding angles. Results have certain guiding significance for the experimental research, theoretical calculation and engineering construction of layered limestone.