Study On Interfical Shear Behavior And Constitutive Relations Of Shotcrete-granite Joints In High Rock Temperature Tunnel

In recent years,a number of high temperature tunnels spring out at home and abroad in the process of infrastructure construction,therefore,a lot of construction experience have been gradually mastered at the same time.However,the relevant theoretical research,mainly in the normal atmospheric temperature and.high temperature tensile properties,have little study been done on it.Thus,the research on the shear performance of the surface at high temperature becomes a hot topic in the paper.The method of indoor direct shear test is adopted in the thesis.Based on the failure mode and its mechanism,the failure model of shear performance of the concrete and granite can be classified to interface failure(F1),compound failure(F2)and concrete interior failure(F3).Through the analysis of the failure modes and shear strength of concrete-granite interface,the influence of shear failure characteristics of the factors with temperature,humidity,normal stress,surface roughness,concrete strength have been determined.Then,combined with shear stress-displacement curves,the curves will be generalized to ideal elastic-brittle-plastic model(S1),elastic-brittle-softening-plastic model(S2),strain-softening model(S3).Thereout,the relationship among the curing condition,the peak strength,the failure mode and the shape curve can be established.Then according to the corresponding characteristic curve,we can describe the classification results with 3 types of constitutive model and fit the constitutive parameters involved in the model.Finally,the concrete curing period tests at different ages show that the failure modes and shape curves have a good relationship and the model curve is basically the same in different ages.The peak strength and residual strength show a logarithmic growth form with different ages.Therefore,the constitutive model under the curing period can be obtained.