一种岩石I型断裂韧度K<sub>Ic</sub>估算方法

Abstract

岩石的I型断裂韧度KIc是表征岩石材料抵抗裂纹失稳扩展即脆断破坏的力学性能指标，而在实验室开展该参数的测试工作往往比较困难。为此，本文基于岩石单轴抗拉强度等效的原则，结合岩石I型断裂韧度与单轴抗拉强度、岩石Hoek-Brown (H-B)强度准则的经验参数mi与单轴抗压和抗拉强度之间的相关关系，提出以岩石单轴抗压强度和参数mi估算岩石I型断裂韧度KIc的经验公式。最后，通过相关试验成果验证了经验公式的可靠性。在缺乏必要的试验数据时，所建议的经验关系式可用于通过岩石单轴抗压强度对I型断裂韧度的初步估算。 The mode I fracture toughness KIc of rocks is a mechanical properties index which characterizes the resistance of instability expansion of inner cracks, namely brittle fracture damages of materials, but it is usually difficult to obtain this parameter in laboratory test. Therefore, based on the equivalent principle of uniaxial tensile strength of rocks, combining the relationship between mode I fracture toughness KIc and tensile strength of rocks with the relationship between experience parameter mi of Hoek-Brown (H-B) strength criterion and uniaxial compressive, tensile strength of rocks, a new estimation method of mode I fracture toughness KIc of rocks based on uniaxial compressive strength and experience parameter mi of rocks is proposed. Lastly, the reliability of the correlation is validated by some related testing results. When the basic testing data are unavailable, the proposed correlation can provide a preliminary estimation value of mode I fracture toughness KIc by the uniaxial compressive strength of rocks.