冻融岩体力学特性实验研究

岩石的冻融破坏是寒区岩石工程中常遇到的主要病害之一。通过对3种岩石进行冻融循环试验及电镜微观扫描的方法,研究了不同性质的岩石在冻融条件下的劣化损伤机制,分析了其冻融破坏机理; 并针对不同性质的岩石总结提出了2种不同的冻融劣化模式:裂隙扩展劣化模式和颗粒析出劣化模式; 通过不同冻融循环次数后的3种饱和岩石单轴抗压强度试验,得到了不同性质岩石的单轴抗压强度与冻融循环次数的拟合关系表达式,初步量化了循环冻融对寒区岩石强度衰减的影响,具有一定参考价值,为今后岩石冻融劣化研究和寒区工程建设及工程安全运营提供了可靠的依据。

EXPERIMENTAL RESEARCH ON MECHANICAL CHARACTERISTCS OF ROCK WITH CYCLES OF FREEING-THAWING ACTION

the rock failure due to freeze-thaw weathering is a main engineering problem which often occurs in the rock engineering in cold regions. The rock-degradation and deterioration mechanism and mechanical characteristics for three kinds of rocks have been studied through the cycle freezing-thawing test and the scanning electron microscope method. The mechanism of rock failure due to freezing and thawing is studied. The process of freezing and thawing failure of two basic deterioration modes of different nature rocks is studied by experiments. The two modes are the crack propagation degradation mode and the particle precipitation degradation mode. In order to providing reliable experimental foundation for studying the damage and fracture due to freezing and thawing and the construction and the safety operation of similar projects in cold region, the uniaxial compression tests of three types of rocks suffered from the different cycles of freezing-thawing action are conducted. The fitting relations of the uniaxial compressive strength with the cycles of freezing and thawing are formulated. Preliminary quantitative influence of the cycle of freezing and thawing to the rock strength attenuation has certain reference value.