CAJ | 학술논문

加载速率效应是岩石材料力学特征的一个重要性质。通过对锦屏II级水电站硬脆性大理岩T 2b开展单轴抗拉强度特性的加载速率效应试验，获得以下5点试验规律：(1)在巴西圆盘劈裂试验中，岩样的破坏过程基本可以归纳为应力集中区出现、应力集中区扩展、破坏面形成和岩样破坏4个阶段；(2)岩样的峰值抗拉强度随着加载速率的提高而呈对数增大；(3)应力峰值对应的平均垂直应变随着加载速率的增大而增大，而平均侧向应变随着加载速率的增大而减小；(4)对岩样电镜扫描图进行断口学分析表明，在较低的加载速率(0.000255 MPa/s)下，岩样的破坏面中张拉破坏区域(即镜面区)所占的比例较大，剪切破坏区域(即锯齿区)所占的比例较小，且锯齿区分布均匀规则，而在较高的加载速率(2.55 MPa/s)下，岩样的断口中镜面区比例较小，锯齿区所占的比例较大，且锯齿区剪切脆断痕迹明显；(5)在0.000255 MPa/s的加载速率下，岩样一般劈裂成2块，岩石破坏所消耗的能量较小，而在2.55 MPa/s的加载速率下，岩样破碎成多块，岩样破坏所消耗的能量较大。本文通过宏细观两方面的分析，并引入断口形貌学的分析方法，揭示了硬脆性岩石力学特性加载速率效应的试验特征和内在机制，为岩石破坏机制研究提供一条新的途径。
가재속솔효응시암석재료역학특정적일개중요성질。통과대금병II급수전참경취성대리암T 2b개전단축항랍강도특성적가재속솔효응시험，획득이하5점시험규률：(1)재파서원반벽렬시험중，암양적파배과정기본가이귀납위응력집중구출현、응력집중구확전、파배면형성화암양파배4개계단；(2)암양적봉치항랍강도수착가재속솔적제고이정대수증대；(3)응력봉치대응적평균수직응변수착가재속솔적증대이증대，이평균측향응변수착가재속솔적증대이감소；(4)대암양전경소묘도진행단구학분석표명，재교저적가재속솔(0.000255 MPa/s)하，암양적파배면중장랍파배구역(즉경면구)소점적비례교대，전절파배구역(즉거치구)소점적비례교소，차거치구분포균균규칙，이재교고적가재속솔(2.55 MPa/s)하，암양적단구중경면구비례교소，거치구소점적비례교대，차거치구전절취단흔적명현；(5)재0.000255 MPa/s적가재속솔하，암양일반벽렬성2괴，암석파배소소모적능량교소，이재2.55 MPa/s적가재속솔하，암양파쇄성다괴，암양파배소소모적능량교대。본문통과굉세관량방면적분석，병인입단구형모학적분석방법，게시료경취성암석역학특성가재속솔효응적시험특정화내재궤제，위암석파배궤제연구제공일조신적도경。
The loading rate effect is an important property of rock materials. The research of the Brazilian splitting test at different loading rates on the hard brittle marble in depth in Jinping II hydropower station shows five characteristics:(1) The failure processes can be almost divided into four steps regarding the loading rates,i.e. stress concentration zones,expanding of the stress concentration zones,shaping of the failure and failure. (2) The peak stress in the Brazilian splitting test logarithmic increases with the increase of the loading rate. (3) The loading rate is higher,the average vertical strain is greater,but the average lateral strain is smaller. (4) According to the fractography,the analysis of the microcosmic fracture surfaces shows that the area of mirror district at the rate of 2.55 MPa/s is less than that a of 0.000 255 MPa/s and the shear failure is dominant;furthermore,the sawtooth district of the 0.000 255MPa/s is regular. (5) At the rate of 2.55 MPa/s,the sample breaks into more pieces and the failure is much more violent than that at a lower loading rate. The energy of sample failure at the rate of 2.55 MPa/s is greater than that at the rate of 0.000 255 MPa/s when calculation. The test result is analyzed in view of macroscopic and microscopic studies;and fractography is utilized to explain the mechanism of the rock failure at different loading rates. The analysis method is helpful for the understanding the loading rate effect and its mechanism.