Study On The Composite Pavement Structure Design Of Underground Road

With the development of urban construction, the underground road has entered a stageof rapid development. At present, China has not yet carried out systematic research on theunderground road pavement structure design method, but also lack of technicalspecifications and guidelines. This paper relying on the physical works take systematicstudy on the key technology around the underground road temperature field analysis, thetraffic volume survey, the axle load conversion method, the damage model and themechanical characteristics of underground road composite pavement structure. The researchincludes the following aspects:1．There is an inbuilt temperature sensor in the process of underground roadconstruction that can collect temperature data, And on the basis of the measuredtemperature, build the underground road composite pavement transient temperature fieldanalysis model. In the survey found that the end and the top of cement concrete slab in thecomposite pavement structure of the underground roads have a smaller temperaturedifference, which could not consider the thermal stress of the cement concrete slab in thestructural design.2．In-depth analysis of the Tianjin haihe underground road traffic volume and axleload, presented as a single-axis dual group60KN as an underground road standardaxle-load. Take the tensile strain of asphalt layer bottom and interlaminar shear stress as thedesign index, infers the underground road composite pavement axle load conversionformula.3．The mechanical indicators of underground road AC+CRC composite pavementstructure mainly are the flexural strain at the bottom of asphalt layer, the maximum shearstress in the end of the asphalt layer and Continuous reinforced concrete layer bottombending tensile stress. Comprehensive analysis the influence of the mechanical propertieson the asphalt layer and continuous reinforced concrete layer by all parameters.4．Put forward the fatigue cracking in asphalt layer and interlayer shear fatigue designpatterns of asphalt surface’s thickness, and the fatigue stress no more than to flexural tensilestrength determine the continuous reinforced concrete plate thickness design patterns.