Study on Propergation Characteristics of Crack and Weathering Depending on Inherent Structure of Rock

这对了解岩石风化的机理和程度具有重要意义。为了弄清岩石在干湿循环条件下的力学性能、崩解性能与岩石内在结构之间的关系，进行了岩石的崩解耐久性等室内试验。结果表明，随着干湿条件的重复，岩石固有的孔隙或/和裂缝会增加。认为在重复下获得较低的力学性能和崩解耐久性指数，因为长大的空隙或/和裂纹表现为弱面。在湿化耐久性试验中的许多研究涉及干燥温度、含水量和循环次数对湿化现象的影响。也就是说，我们讨论了由粒度累积曲线得到的参数对破碎产物的依赖性， ...更多信息 在熟化耐久性试验后，参数包括粒度累积曲线中50%有效直径的偏差、2 mm筛下产物的重量比、均匀系数、残余比差的绝对值之和比表面积。湿化耐久性试验的结果表明，湿化现象随着含水量的高偏差而增加，而不受干燥温度的影响。此外，比表面积的偏差等参数可以定量地确定为熟化现象，已经开发了许多方法来确定断裂韧性，其表示为扩展的大小裂缝的特征。断裂韧性测试要求试样具有精确规定的形状。然而，在某些情况下，通常很难或实际上不可能根据需要制备具有软弱岩石或潜在风化岩石的样品。从这一角度出发，讨论了岩石的抗拉或抗压强度、岩石的冲击硬度值（RIHN）、岩石的石英含量等预测岩石断裂韧性的指标。结果表明，断裂韧度与岩石的RIHN值和石英含量有较好的相关性。指出岩石的破碎特性和固有结构决定了裂纹的扩展过程。同时，探讨了声发射技术在裂纹扩展特性估计中的应用。结果表明，声发射技术可以预测混凝土湿化耐久性试验过程中裂纹的扩展特性和扩展过程。少

It is great importance to understand of the mechanism and to know of the extent of the weathring of rocks. In order to clarify the relationship between the mechanical properties, the slaking properties, and the inherent structure of rocks after the repetition of dry and wet condition, the laboratory tests such as the slaking durability test and so on were carried out. The results show that the inherent voids or/and cracks of the rocks were increased as the repetition of dry and wet condition. It is considered that lower mechanical properties and the slaking durability index were obtained under the repetition, because grown-up voids or/and cracks behave like a weakness plane. Much of the research in the slaking durability test is concerned with the effect of the dry temperature, the moisture content, and the number of cycle on the slaking phenomenon. Namely, we discussed the dependence of the parameters which were obtained by the grain size accumulation curve on the fragmentation produc … More ts after the slaking durability test. The parameters consisted of the deviation of the 50 % effective diameter in the grain size accumulation curve, the weight ratio of the products under the 2mm sieve, the uniformity coefficient, the summation of absolute value of the residual ratio difference, and the specific surface area. The results of the slaking durability test would be presented that the slaking phenomenon is increased with high deviation of the moisture content without the effect of the dry temperature Moreover, the parameter such as the deviation of the specific surface area can be determined as the slaking phenomenon in quantity.A number of approaches have been developed to determine the fracture toughness which is expressed as the magnitude of the propagation characteristics of cracks. The fracture toughness test requires the specimen to be in the precisely prescribed shape. However, it is often difficult or practically impossible in some cases, to prepare the specimen as required, with weak rocks or potentially weathering rocks. From this point of view, we discussed the index such as the tensile or the compressive strength of rocks, the rock impact hardness number (RIHN) , and the quartz content of rocks for prediction of the fracture toughness. The results show that the fracture toughness has a generally good correlation with the RIHN and the quartz content of rocks. It indecates that the propagation process of cracks depends on the fragmentation property and the inherent structure of rocks. Moreover, AE technique was tried to explore the possibility of its application in the estimation of the propagation characteristics of cracks. It is shown that the propagation characteristics of cracks and the propagation process during the slaking durability test can be predicted by using AE technique. Less