砂岩Ⅰ型断裂韧度及其与强度参数的相关性研究  

Study of mode-Ⅰ fracture toughness and its correlation with strength parameters of sandstone

作　　者：邓华锋[1] 朱敏[1] 李建林[1] 王宇[1] 罗骞[1] 原先凡[1] 

机构地区：[1]三峡大学三峡库区地质灾害教育部重点实验室,湖北宜昌443002

出　　处：《岩土力学》2012年第12期3585-3591,共7页Rock and Soil Mechanics

基　　金：973计划前期研究专项课题(No.2012CB426502);宜昌市科学技术研究与开发项目(No.A2011-302-6);三峡大学科学基金(No.KJ2011B008)

摘　　要：岩石的破坏和断裂是密切相关的,岩石强度准则的材料参数和断裂理论的断裂韧度是存在特定关系的,基于此,设计了紧凑的试验方案,对干燥和饱水状态下的砂岩试样进行了3点弯曲断裂韧度试验和抗压、抗拉强度试验,试验结果表明,饱水后,砂岩的Ⅰ型断裂韧度软化效应明显,饱水试样和干燥试样的K Ic比值与砂岩抗压强度的软化系数相近,具有相似的软化效应。同时,从理论上分析了岩石I型断裂韧度与抗拉强度之间的关系,并结合大量的试验数据进行了验证,相关结论为以往的岩石I型断裂韧度与抗拉强度之间的数据统计拟合公式提供了理论基础。最后,统计分析了砂岩Ⅰ型断裂韧度与抗压强度、黏聚力、内摩擦角等强度参数之间的关系。研究成果对于把握砂岩Ⅰ型断裂韧度及其与强度参数的相关性具有较大的参考价值,相关的分析结论、试验方法和试验结果也可以为其他类型岩石的研究提供有益的参考。Rock damage and fracture is closely related to each other, and there is a specific relationship between strength criterion parameters and fracture toughness of fracture theory. Based on these, a compact test scheme was designed for three-point bending fracture toughness test, compressive strength test and tensile strength test of sandstone under the states of dry and saturated. The test results show that after saturated in water, the softening effect of mode Ⅰ fracture toughness of sandstone was obviously, and the fracture toughness Kκ ratio of water-saturated sample and dry sample is close to the sandstone softening coefficient of the compressive strength, showing a similar softening effect. Meanwhile, the relationship of the mode Ⅰ fracture toughness and the tensile strength was discussed through theoretical analysis; and a large number of experimental data was used to verify the analysis results. As a result the analysis results can provide a theoretical basis for the previous statistical fitting formulas between mode Ⅰ fracture toughness and the tensile strength. Finally, statistics and analysis of the relationship between mode Ⅰ fracture toughness and compressive strength, cohesion, friction angle and some other strength parameters was made. Research results have an important reference value for the study of the correlation between mode Ⅰ fracture toughness and strength parameters of sandstone, and the related test methods, test results and conclusions can provide favorable evidences for the experimental research of other types of rocks.

关 键 词：断裂韧度 饱水砂岩 抗拉强度 软化系数 相关性 

分 类 号：TU452[建筑科学—岩土工程]