CAJ | 학술논문

利用变频动态加载岩石力学试验系统对直径为50 mm,长度分别为50,75,100,125 mm的花岗岩试样进行中低应变率范围内的加载试验.研究结果表明:(1)试样强度具有显著的应变率依赖性,随着应变率增大,压缩强度近似以乘幂关系增大.(2)静载和准动态加载条件下,岩石强度基本上随试样长度的增加而减小.(3)不同应变率加载条件下,直径为50 mm的试样,长径比不小于2时,方能取得基本稳定的试验结果.(4)峰值应变随试样尺寸的增大逐渐减小.(5)割线模量E50和线性段弹性模量Et随试样尺寸的增大而增大,且Et>E50.(6)破裂形式具有显著的应变率效应,随着应变率的增高,破碎程度加大;其尺寸效应则表现为:应变率ε&<10-3 s-1时,随着尺寸的增大,破裂形式表现为劈裂–锥形破裂–剪切破裂的过程;应变率ε&>10-2 s-1时,破裂形式则直接由锥形破裂变为剪切破裂.
이용변빈동태가재암석역학시험계통대직경위50 mm,장도분별위50,75,100,125 mm적화강암시양진행중저응변솔범위내적가재시험.연구결과표명:(1)시양강도구유현저적응변솔의뢰성,수착응변솔증대,압축강도근사이승멱관계증대.(2)정재화준동태가재조건하,암석강도기본상수시양장도적증가이감소.(3)불동응변솔가재조건하,직경위50 mm적시양,장경비불소우2시,방능취득기본은정적시험결과.(4)봉치응변수시양척촌적증대축점감소.(5)할선모량E50화선성단탄성모량Et수시양척촌적증대이증대,차Et>E50.(6)파렬형식구유현저적응변솔효응,수착응변솔적증고,파쇄정도가대;기척촌효응칙표현위:응변솔ε&<10-3 s-1시,수착척촌적증대,파렬형식표현위벽렬–추형파렬–전절파렬적과정;응변솔ε&>10-2 s-1시,파렬형식칙직접유추형파렬변위전절파렬.
@@@@The static and quasi-dynamic tests on granite specimens under various strain rates are conducted by using rock dynamic loading system. The specimens are 50 mm in diameter,with the length of 50,75,100,125 mm,respectively. The research results are drawn as follows:(1) Specimen strength is significantly dependent on strain rates and increases with the growth of strain rates with a power relationship. (2) Under static and quasi-dynamic loading conditions,rock strength generally decreases with the increase in specimen length. (3) When the diameter of specimen is 50 mm,the aspect ratio should be not smaller than 2;then steady test results can be obtained under different strain rates. (4) Peak strain under each strain rate decreases with increasing specimen size. (5) Both of secant modulus E50 and elastic modulus Et increase with increasing specimen size;and Et is larger than E50. (6) Failure mode is significantly dependent on strain rates and failure is serious when the strain rate increases. When strain rate ε&<10-3 s-1,failure mode has a process of split failure-taper failure-shear failure;when strain rate ε&>10-2 s-1,the failure mode changes from taper failure to shear failure directly.