Research On The Mechanism Of Temperature Difference Effect Of High Rock Slope In High Altitude Area

Western mountainous terrain fluctuation in China,the human engineering activity is difficult,such as when to build a road,will inevitably produce artificial slope,vertical height h as artificial rock slope>30 m called high slope,once the high slope instability will cause great loss to the country and people.The influence factors of rock high slope stability is more,our predecessors have made a lot of research,but at an altitude of 1500 m?4000 m within the scope of the region due to its larger temperature difference between day and night,the four seasons temperature difference,temperature difference influence on the stability of high rock slope is also nots allow to ignore.The influence of temperature difference on the stability of rock high slope is mainly manifested in two aspects:on the one hand,the repeated freezing-thawing of pore water in the rock causes micro-cracks in the rock,which leads to the decrease of rock strength.On the other hand,the fracture water in the rock joints is repeatedly freeze-thaw,which leads to the expansion of the rock mass,which leads to the decrease of rock mass strength(ice splitting).In ganzi county of sichuan province in national highway 317 line K208+200 artificial rock high slope as an example,through the scene to carbonaceous killas sample indoor freeze-thaw test,the number of freeze-thaw cycle times of the various physical and mechanical properties of the carbonaceous killas,the results show that with the increase of freeze-thaw cycles,the quality of the killas specimens,uniaxial compressive strength and elastic modulus,cohesive force,internal friction Angle are exponential trend down,and poisson's ratio of the specimens is linear trend rise;In freezing and thawing cycles were less than 45 times,killas order parameters of the rate of change of size of the specimens for E>?>?c>c>?>m,and after the freeze-thaw cycles is more than 45 times,killas order parameters of the rate of change of size of the specimens for ?>E>?c>c>?>m.Then freezing and thawing cycles and killas specimens mechanics parameter relation curve fitting synthetic function,the function and you in 3DEC constitutive function,using C++ custom 3DEC freeze-thaw constitutive model,using the constitutive model of K208+200 slope stability of numerical.analysis,the analysis results show that with the increase of number of freezing and thawing,K208+200 horizontal displacement of slope surface monitoring sites increases,the slope safety factor is reduced,the slope stability state by basically stable gradually into the unstable state.