Analysis On The Strength Damage And Fracturing Feature Of Single Fractured Rock Mass Under The Environment Of Low Temperature

With the increasing investment of nation for engineering construction in cold regions and the intensification of the global climate and environment deterioration, the engineering disaster phenomenon in cold regions increase constantly, which has become a major problem for engineering construction and stability in cold regions. Being the product of the geological process, the rock mass contains more joints, fissures and other discontinuity surfaces. The existence of discontinuity surfaces has great influence for the strength of rock mass and various mechanical responses. Moreover, under the freezing and thawing actions, the influencing effect of discontinuity surfaces is more complex. So, correctly understanding and solving the problems of rock mass appeared in the cold regions must from the viewpoint of fractured rock mass.In this paper, single fractured rock mass of different angles(0°、45°) are taken as the research object to study the physical parameters, mechanical strength and fractured characteristics under the impact of freeze-thaw and load. Firstly, base on the relevant theories of similar modeling test. Through designing orthogonal test to determine the ideal mix proportion of the materials of simulative Cretaceous sandstone and prepare the test specimen of single fractured rock mass meeting the test requirements; make contrast and analysis for the similarities and differences of physical parameters of fractured rock masses with two angles to test out the changes of thermal physical parameters of rock-like material under different temperatures and analyze their corresponding influence factors; through the freeze-thaw cycle test, make the track record for the quality and apparent changes of fractured rock mass; take use of the uniaxial compression test to make systematic research for the strength loss of fractured rock mass as well as the freeze-thaw damaging and degrading mechanism; also, through the means of numerical simulation, make simulation analysis on theevolution of temperature field and frost heave force inside the fractured rock mass under the cyclic freezing and thawing actions; establish the rock fractured criterion after cyclic freezing and thawing actions, as well as explore the crack initiation and extension model of fractured rock mass and its mechanical mechanism under loading.In this paper, through the method of similar tests combining with theoretical derivation and numerical simulation, make a research on the strength and fractured characteristics of single fractured rock mass under the cyclic freezing and thawing actions and load. Therefore,the corresponding research results have certain reference value for engineering design and disaster protection of fractured rock mass in cold regions.