【摘要】 岩石在冻融循环作用下的损伤特性对评价寒区工程的稳定性和耐久性具有十分重要的意义.选取吉林集安某古建筑的花岗岩作为试样,在当地最低气温(-36.5 ℃)下反复冻融20次,冻融前后岩样的单轴压缩试验和电镜观测结果表明:经历多次冻融后岩石的单轴抗压强度下降5%~15%,弹性模量下降32%~46%,泊松比提高10%~19%,岩样中旧的裂隙明显变宽并产生新的裂隙.研究发现:低温冻融循环虽然对花岗岩的质量影响不明显,但对其强度、刚度及变形特性均有较大影响;岩石在低温冻融循环作用下损伤扩展的机理是裂隙增大、增多或发生扩展,从而使岩石强度、刚度降低,变形增大.图4,表2,参8.更多还原

【Abstract】 Freeze-thawing damage characteristics of rocks have the great significance to evaluate the stability and durability of engineering in severe cold regions.The experiments were performed by testing coarse grain granite frozen and thawed 20 times at the local minimum temperature(-36.5 ℃) from building material of a antique buildingl in Jian city Jilin Province,China. It is determined that strength decreased 5%～15%,modulus of elasticity 5%～15% and Poisson ratio increased 10%～22% by the uniaxial compression test of specimen undergoing freeze-thaw cycles.It is indicated by SEM test that cracks may be expanded.Analysis of the samples showed freeze-thawing cycles has no apparent impact on quantity;more impact,however,on strength,stiffness and deformation characteristics.The damage of rock on freeze-thaw is that new cracks yielded and intrinsic cracks expanded make a reduction in strength and stiffness, augmentation in deformation.4figs.,2tAbs.,8refs.更多还原