CAJ | 학술논문

脆性指标与起裂应力作为岩石力学性质的内在体现，均反映岩石的非均质性和结构上的差异，二者存在一种必然的联系，通过理论研究和算例分析来探讨起裂应力水平与基于单轴抗压、抗拉强度比值的脆性指标的关系。首先，归纳总结基于压拉比、全应力-应变特征及硬度或坚固性的28种基本脆性测试方法。然后，研究硬脆性岩石单轴压缩起裂机制，讨论基于裂纹体积应变拐点的起裂应力确定方法，并定义起裂应力水平指标K。最后，结合具体工程算例探讨岩石起裂应力与基于压拉比的脆性指标的函数关系，深入验证起裂应力水平和脆性指标间内在联系的必然性。得出以下结论：(1)以岩石单轴抗压、抗拉强度为纽带，建立起裂应力水平和脆性指标间的函数关系，根据单轴压缩起裂应力与单轴抗拉强度的关系，进一步验证脆性指标与起裂应力水平存在内在联系的必然性。(2)岩石起裂应力水平与脆性指标B 5和B 6存在明显的函数关系，起裂应力水平与B 5呈幂函数关系，与B 6呈线性函数关系，相关系数均大于85%。(3)采用起裂应力水平指标重新定义脆性指标，通过岩石的室内单轴压缩试验，由起裂应力水平可以快速得到岩石的脆性指标。通过这一研究，丰富了岩石起裂应力与脆性指标的关系，为脆性指标的计算提供了一条新思路。
취성지표여기렬응력작위암석역학성질적내재체현，균반영암석적비균질성화결구상적차이，이자존재일충필연적련계，통과이론연구화산례분석래탐토기렬응력수평여기우단축항압、항랍강도비치적취성지표적관계。수선，귀납총결기우압랍비、전응력-응변특정급경도혹견고성적28충기본취성측시방법。연후，연구경취성암석단축압축기렬궤제，토론기우렬문체적응변괴점적기렬응력학정방법，병정의기렬응력수평지표K。최후，결합구체공정산례탐토암석기렬응력여기우압랍비적취성지표적함수관계，심입험증기렬응력수평화취성지표간내재련계적필연성。득출이하결론：(1)이암석단축항압、항랍강도위뉴대，건립기렬응력수평화취성지표간적함수관계，근거단축압축기렬응력여단축항랍강도적관계，진일보험증취성지표여기렬응력수평존재내재련계적필연성。(2)암석기렬응력수평여취성지표B 5화B 6존재명현적함수관계，기렬응력수평여B 5정멱함수관계，여B 6정선성함수관계，상관계수균대우85%。(3)채용기렬응력수평지표중신정의취성지표，통과암석적실내단축압축시험，유기렬응력수평가이쾌속득도암석적취성지표。통과저일연구，봉부료암석기렬응력여취성지표적관계，위취성지표적계산제공료일조신사로。
Brittleness index and crack initiation stress,as the intrinsic reflection of mechanical properties for rock,reflect the heterogeneity and structural differences of rocks. Supposing that there exists a certain inevitable relationship between them,theoretical research and case study are conducted. Firstly,28 kinds of basic brittleness testing methods,based on ratio of uniaxial compressive strength to tensile strength,the whole stress-strain characteristics and hardness or soundness,are summarized. Secondly,the crack initiation mechanism for brittle rocks under uniaxial compression is studied. The method to determine crack initiation stress level is discussed by means of inflection points of crack volume strain curve;and the crack initiation stress level is defined as K. Finally,two cases are given to expose the function relationship between crack initiation stress and brittleness indices. Some conclusions are drawn as follows:(1) Based on the achievement of predecessors,by using the uniaxial compressive and tensile strengths,it is found that there exists a certain relation between crack initiation stress level and brittleness indices. (2) There are obvious function relationship between crack initiation stress level and brittleness indices B 5 ,B 6 . To B 5 is power function relation,and to B6 is linear function relation. The correlation coefficients are both greater than 85%,showing a strong correlation. (3) Brittleness index is redefined by crack initiation stress level,which can be obtained easily and quickly based on crack initiation stress level under uniaxial compression test. This study enriches the relationship between crack initiation stress and brittleness indices,and provides a new idea to determine the brittleness indices.