岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2009年
12期
2391-2404
,共14页
杨圣奇%戴永浩%韩立军%贺永年%李玉寿
楊聖奇%戴永浩%韓立軍%賀永年%李玉壽
양골기%대영호%한립군%하영년%리옥수
岩石力学%预制裂隙%脆性大理岩%变形%强度%贯通模式
巖石力學%預製裂隙%脆性大理巖%變形%彊度%貫通模式
암석역학%예제렬극%취성대리암%변형%강도%관통모식
rock mechanics%pre-existing fissures%brittle marble%deformation%strength%failure mode
采用岩石力学伺服试验机,对断续预制裂隙脆性大理岩进行单轴压缩试验,基于全程变形曲线的试验结果,分析裂隙参数(岩桥倾角、裂隙间距、裂隙长度、裂隙数目与裂隙倾角)几何分布对大理岩变形破坏特征的影响规律.研究结果表明,与完整大理岩相比,断续预制裂隙大理岩变形呈现出局部化渐近破坏特征,其峰值强度、弹性模量及峰值轴向应变均明显降低,且降低幅度与预制裂隙参数分布形式密切相关;但变形模量除裂隙间距48 mm(降幅24.8%)、含119°岩桥倾角(降幅23.7%)以及含60°裂隙倾角(降幅43.8%)的岩样以外,其他含2条预制裂隙岩样的变形模量降幅均为-3.8%~7.8%,差异较小.裂隙长度越长、裂隙数目越多及裂隙倾角越大,其峰值强度、弹性模量及峰值轴向应变也越低;而岩桥倾角和裂隙间距与力学参数之间规律性不明显.岩样宏观贯通模式主要呈现出拉贯通、压贯通、剪贯通和混合贯通4种,且与预制裂隙的几何分布密切相关.完整岩样呈典型的轴向劈裂拉贯通模式.含较短裂隙长度(16 mm)及较小裂隙倾角(30°)的岩样呈现出拉贯通模式;而含较长裂隙长度(24 mm)和较大裂隙倾角(60°)的岩样呈现出拉剪混合贯通模式.裂隙间距越小以及裂隙数目越多,岩样的贯通模式趋于复杂,呈现出拉剪压混合贯通模式.
採用巖石力學伺服試驗機,對斷續預製裂隙脆性大理巖進行單軸壓縮試驗,基于全程變形麯線的試驗結果,分析裂隙參數(巖橋傾角、裂隙間距、裂隙長度、裂隙數目與裂隙傾角)幾何分佈對大理巖變形破壞特徵的影響規律.研究結果錶明,與完整大理巖相比,斷續預製裂隙大理巖變形呈現齣跼部化漸近破壞特徵,其峰值彊度、彈性模量及峰值軸嚮應變均明顯降低,且降低幅度與預製裂隙參數分佈形式密切相關;但變形模量除裂隙間距48 mm(降幅24.8%)、含119°巖橋傾角(降幅23.7%)以及含60°裂隙傾角(降幅43.8%)的巖樣以外,其他含2條預製裂隙巖樣的變形模量降幅均為-3.8%~7.8%,差異較小.裂隙長度越長、裂隙數目越多及裂隙傾角越大,其峰值彊度、彈性模量及峰值軸嚮應變也越低;而巖橋傾角和裂隙間距與力學參數之間規律性不明顯.巖樣宏觀貫通模式主要呈現齣拉貫通、壓貫通、剪貫通和混閤貫通4種,且與預製裂隙的幾何分佈密切相關.完整巖樣呈典型的軸嚮劈裂拉貫通模式.含較短裂隙長度(16 mm)及較小裂隙傾角(30°)的巖樣呈現齣拉貫通模式;而含較長裂隙長度(24 mm)和較大裂隙傾角(60°)的巖樣呈現齣拉剪混閤貫通模式.裂隙間距越小以及裂隙數目越多,巖樣的貫通模式趨于複雜,呈現齣拉剪壓混閤貫通模式.
채용암석역학사복시험궤,대단속예제렬극취성대리암진행단축압축시험,기우전정변형곡선적시험결과,분석렬극삼수(암교경각、렬극간거、렬극장도、렬극수목여렬극경각)궤하분포대대리암변형파배특정적영향규률.연구결과표명,여완정대리암상비,단속예제렬극대리암변형정현출국부화점근파배특정,기봉치강도、탄성모량급봉치축향응변균명현강저,차강저폭도여예제렬극삼수분포형식밀절상관;단변형모량제렬극간거48 mm(강폭24.8%)、함119°암교경각(강폭23.7%)이급함60°렬극경각(강폭43.8%)적암양이외,기타함2조예제렬극암양적변형모량강폭균위-3.8%~7.8%,차이교소.렬극장도월장、렬극수목월다급렬극경각월대,기봉치강도、탄성모량급봉치축향응변야월저;이암교경각화렬극간거여역학삼수지간규률성불명현.암양굉관관통모식주요정현출랍관통、압관통、전관통화혼합관통4충,차여예제렬극적궤하분포밀절상관.완정암양정전형적축향벽렬랍관통모식.함교단렬극장도(16 mm)급교소렬극경각(30°)적암양정현출랍관통모식;이함교장렬극장도(24 mm)화교대렬극경각(60°)적암양정현출랍전혼합관통모식.렬극간거월소이급렬극수목월다,암양적관통모식추우복잡,정현출랍전압혼합관통모식.
Uniaxial compression experiments were carried out for brittle marble with pre-existing fissures by the rock mechanics servo-controlled testing system. Based on the experimental results of complete deformation curves,the effect of the geometric distribution of fissure parameters(bridge angle,fissure distance,fissure length,fissure number and fissure angle) on the deformation and failure properties of brittle marble were analyzed. Compared with the intact marble,the marble with pre-existing fissure takes on the localization deformation and asymptotic failure. The peak strength,elastic modulus and peak axial strain of marble with pre-existing fissure are all lower than that of intact marble,and the reduction extent is closely related to the distribution forms of pre-existing fissure. Expect for the marble sample with fissure distance equals 48 mm(the reduction amplitude of deformation modulus is 24.8%),the marble specimen with bridge angle equals 120°(23.7%) and the marble sample with fissure angle equals 60°(43.8%),the reduction amplitude of deformation modulus is in the range of -3.8% to 7.8% for other marble samples with two pre-existing fissures,in which the difference is smaller. The longer the fissure length is,the more the fissure number is and the larger the fissure angle is;the lower the peak strength,the elastic modulus and peak axial strain are;however there are no distinct laws between the bridge angle,fissure distance and mechanical parameters of marble sample. The failure mode of marble specimen takes mainly on the four modes:tensile mode,compression mode,shear mode and mixed mode,which are closely related to the geometric distributions of pre-existing fissure. The intact marble sample takes on the typically axial splitting tensile mode. The rock samples with the shorter fissure length(16 mm) and the smaller fissure angle(30°) take on the tensile mode,however the rock samples with the longer fissure length(24 mm) and the larger fissure angle(60°) take on mixed mode(shear and tensile). The smaller the fissure distance is,and the more the fissure number is,the more complexed the coalescence mode of rock samples is,which takes on mixed mode(shear,tensile and compression).