Experimental Study On Bearing Performance Of Tunnel Crack Lining Residual Loss

With the increasingly improvement of road network at all levels,our country is by highway construction boom has turned to curing period.The survey found that,with the increase in the completion of the highway tunnel,the impact of geology,design,construction and operations management and repair and maintenance and other factors,and there are different levels of disease phenomena.In this paper,the Ministry of Transport applied basic research project-"Disease tunnel simulation test technology and system development" as a support.It is carried out research work for " the derivation of similarity theory of disease "," the development and testing of similar material"," the experimental design",and "the lining cracking similarity simulation experiment".It is based on the scaled test similar material preparation technology research and the similarity theory and fracture mechanics theory and the tunnel lining cracks of statistical analysis and finite element theory.This paper makes a similar scheme of model test.It studies changes of lining crack damage of tunnel residual bearing performance.That is the presence of longitudinal cracks for secondary lining.It analysis the interaction of the displacement around the tunnel-load and axial force-load,moment-load,the contact pressure of surrounding rock and lining,and the changes of two lining crack width.Main research work of this thesis is as follows:First,based on the site of crack detection data,it ueses mathematical expectation,variance,skewness and kurtosis of the four statistics outline and reflects the characteristics of crack distribution.By using ? distribution fitting,it describes the whole picture crack distribution.Second,by using ANSYS finite element software,this paper analyzes the safety conditions under design conditions and the presence of cracks on mechanical behaviors for V-class rock secondary lining,and it obtains the trend of crack tip stress intensity under the same load.Third,it is derived for the elastic model similarity index and similarity criterion and plasticity model and similarity criterion of similarity index.The physical and mechanical indexes are determination method.The impact factors of similar mechanical properties include production conditions,mold pressure,sand-cement ratio,water consumption,the amount of retarder and maintenance time.It is given large scale modelsimilar material ratio and mechanical parameters: secondary lining surrounding rock.Finally,the physical model test is designed.That is the large scale model test of the geometrical and physical similarity relation,similarity model material,model box design,test instruments and equipment required for installation and test steps.It is studied the phenomenon of tunnel lining crack disease,occurrence and development process under the conditions of external load,and lining bearing performance changes with cracks and damage characteristics.Based on the construction monitoring data,it studies vault subsidence and peripheral convergence for V grade rock conditions.Secondary lining of contact pressure,axial forces and bending moments is changed with time in different levels of the surrounding rock for V grade rock conditions.