岩土工程学报
巖土工程學報
암토공정학보
CHINESE JOURNAL OF GEOTECHNICAL ENGINEERING
2015年
4期
727-733
,共7页
席婧仪%陈忠辉%朱帝杰%陈庆丰
席婧儀%陳忠輝%硃帝傑%陳慶豐
석청의%진충휘%주제걸%진경봉
不等长共线裂纹%相互作用%应力强度因子%起裂角%类岩材料试验
不等長共線裂紋%相互作用%應力彊度因子%起裂角%類巖材料試驗
불등장공선렬문%상호작용%응력강도인자%기렬각%류암재료시험
unequal collinear crack%interaction%stress intensity factor%initiation angle%rock-like material experiment
天然岩体中含有数量众多的裂隙且绝大多数为不等长裂隙，而那些具有一定尺度和规模的主控裂隙对岩体稳定性起决定作用。为研究不等长裂纹相互作用规律及主控裂纹起裂规律，基于Kachanov法，推导了远场受力的两条拉剪不等长共线裂纹的尖端应力强度因子表达式并从理论上分析了裂纹间距对裂纹相互作用的影响；通过最大周向应力准则，计算了单轴受拉时不同裂纹倾角的主控裂纹起裂角，绘出理论断裂准则曲线；推算滑动裂纹的应力强度因子，对含不等长裂纹的类岩试件进行单轴压缩试验。结果表明：当裂纹间距大于等于小裂纹长度时，小裂纹对主控裂纹的起裂几乎无影响；主控裂纹起裂角只与裂纹角有关，单轴受拉时，起裂角随裂纹角增大而减小，单轴受压时，起裂角随裂纹角增大而增大；当裂纹倾角小于30°时，起裂临界荷载急剧增大。
天然巖體中含有數量衆多的裂隙且絕大多數為不等長裂隙，而那些具有一定呎度和規模的主控裂隙對巖體穩定性起決定作用。為研究不等長裂紋相互作用規律及主控裂紋起裂規律，基于Kachanov法，推導瞭遠場受力的兩條拉剪不等長共線裂紋的尖耑應力彊度因子錶達式併從理論上分析瞭裂紋間距對裂紋相互作用的影響；通過最大週嚮應力準則，計算瞭單軸受拉時不同裂紋傾角的主控裂紋起裂角，繪齣理論斷裂準則麯線；推算滑動裂紋的應力彊度因子，對含不等長裂紋的類巖試件進行單軸壓縮試驗。結果錶明：噹裂紋間距大于等于小裂紋長度時，小裂紋對主控裂紋的起裂幾乎無影響；主控裂紋起裂角隻與裂紋角有關，單軸受拉時，起裂角隨裂紋角增大而減小，單軸受壓時，起裂角隨裂紋角增大而增大；噹裂紋傾角小于30°時，起裂臨界荷載急劇增大。
천연암체중함유수량음다적렬극차절대다수위불등장렬극，이나사구유일정척도화규모적주공렬극대암체은정성기결정작용。위연구불등장렬문상호작용규률급주공렬문기렬규률，기우Kachanov법，추도료원장수력적량조랍전불등장공선렬문적첨단응력강도인자표체식병종이론상분석료렬문간거대렬문상호작용적영향；통과최대주향응력준칙，계산료단축수랍시불동렬문경각적주공렬문기렬각，회출이론단렬준칙곡선；추산활동렬문적응력강도인자，대함불등장렬문적류암시건진행단축압축시험。결과표명：당렬문간거대우등우소렬문장도시，소렬문대주공렬문적기렬궤호무영향；주공렬문기렬각지여렬문각유관，단축수랍시，기렬각수렬문각증대이감소，단축수압시，기렬각수렬문각증대이증대；당렬문경각소우30°시，기렬림계하재급극증대。
There are many cracks in the natural rock mass and the majority of the cracks are unequal. The main control crack with a certain scale decides the stability of the rock mass. In order to study the interaction rules of the cracks with unequal length and the initiation rules of the main control crack, based on the Kachanov method, the expressions for the stress intensity factors of two collinear cracks with unequal length loaded by uniaxial tractions at infinity are derived, and the influence of the crack distance on the interaction is theoretically analyzed. The initiation angle of the main crack under uniaxial tension is calculated by the maximum circumferential stress criteria and the theoretical fracture criteria curves are drawn. The stress intensity factors of sliding close cracks are derived and the compression tests on rock-like specimens with two unequal collinear cracks are performed. The results show that the small crack almost has no effect on the initiation of the main control crack when the crack distance reaches the length of the small crack. The initiation angle of the main control crack is only related to the crack incline angle, and it decreases with the increase of the crack angle when the cracks are loaded by uniaxial tension and it increases with the increase of the crack angle when the cracks are loaded by uniaxial compression. The initial critical load increases rapidly when the crack incline angle is less than 30°.
