地震工程学报
地震工程學報
지진공정학보
China Earthquake Engineering Journal
2015年
2期
541-545
,共5页
张锐%朱术云%孙强%武富强
張銳%硃術雲%孫彊%武富彊
장예%주술운%손강%무부강
高温%单轴压缩%分形维数%扫描电镜
高溫%單軸壓縮%分形維數%掃描電鏡
고온%단축압축%분형유수%소묘전경
high temperature%uniaxial compression%fractal dimension%scanning electron micros-copy (SEM)
温度是影响岩石物理力学性质的重要因素,对不同温度作用后灰岩单轴压缩的碎块进行统计分析,结果表明灰岩的块度分布是个分形,分形维数 D 是反映高温后灰岩破碎程度恰当的特征统计量,同时 D 表现出随温度的增大而减小的性质。在此基础上,通过扫描电镜分析,获得温度对岩石力学性质的影响主要与组成岩石矿物性质和内部微观结构有关,而不同温度的作用会影响岩石矿物组成成分和岩石的晶格结构,在灰岩的扫描电镜结果对比中已发现微观形貌特征的差异,这可从内在机制方面解释不同温度下灰岩分维值变化特征。
溫度是影響巖石物理力學性質的重要因素,對不同溫度作用後灰巖單軸壓縮的碎塊進行統計分析,結果錶明灰巖的塊度分佈是箇分形,分形維數 D 是反映高溫後灰巖破碎程度恰噹的特徵統計量,同時 D 錶現齣隨溫度的增大而減小的性質。在此基礎上,通過掃描電鏡分析,穫得溫度對巖石力學性質的影響主要與組成巖石礦物性質和內部微觀結構有關,而不同溫度的作用會影響巖石礦物組成成分和巖石的晶格結構,在灰巖的掃描電鏡結果對比中已髮現微觀形貌特徵的差異,這可從內在機製方麵解釋不同溫度下灰巖分維值變化特徵。
온도시영향암석물리역학성질적중요인소,대불동온도작용후회암단축압축적쇄괴진행통계분석,결과표명회암적괴도분포시개분형,분형유수 D 시반영고온후회암파쇄정도흡당적특정통계량,동시 D 표현출수온도적증대이감소적성질。재차기출상,통과소묘전경분석,획득온도대암석역학성질적영향주요여조성암석광물성질화내부미관결구유관,이불동온도적작용회영향암석광물조성성분화암석적정격결구,재회암적소묘전경결과대비중이발현미관형모특정적차이,저가종내재궤제방면해석불동온도하회암분유치변화특정。
Temperature is an important factor that influences the physical and mechanical proper-ties of rocks.Many scholars have studied various types of rock crushing,but few have examined the characteristics of crushed limestone previously exposed to different temperatures.This study involved a heating limestone specimen,50 mm in diameter and 100 mm in height,in a high tem-perature furnace heating cylinder before performing a uniaxial crushing experiment.Various phe-nomena were observed including axial splitting and bursting strength at low temperature.Howev-er,the strength of fracturing and splitting at high temperature decreased significantly as cleavage was simultaneously reduced.Sample pieces were completely reassembled and similarly sized frag-ments grouped together.Fractal mathematical theory applied to the analysis of rock fragments in-dicated that limestone block distribution is a fractal.Therefore,the fractal dimension D was con-sidered an appropriate statistic to represent the characteristics of limestone crushed after exposure to high temperatures.The fractal dimension D has a negative correlation with temperature where it decreases with increasing temperature.The experimental data was represented in the rectangu-lar coordinate system by plotting temperature on the X axis and fractal dimension on theY axis in a scatter plot.Linear regression used for curve fitting the data resulted in y =0.001 9 +2.506 2x and a very large correlation coefficient.The observed influence of temperature on limestone me-chanical properties mainly involved mineral physical properties and changes in microstructure. Mineral composition and crystal lattice structure may change when a rock is exposed to different temperatures.Fragment comparison with scanning electron microscope (SEM)revealed that limestone subjected to high temperature had different microstructural characteristics than un-treated limestone.Room temperature limestone had a smooth surface.Limestone subjected to high temperatures had an uneven surface and partially broken cement.The rock surface appeared to contain long,wide fissures across grains,rough mineral grain surfaces,and increased detrital material.These characteristics reduced the mechanical properties and caused the change in fractal dimension.This internal mechanism in the limestone explains why fractal dimension decreases with increased temperature.In addition,limestone samples were gray-black at room temperature and light gray when heated to high temperatures.High-temperature exposure caused calcium car-bonate formation and magnesium carbonate oxidation that led to the observed color change.