隧道沥青铺装上下层应变响应特性及其影响因素的实测研究OA

To reveal the variation law of strain response of the tunnel asphalt pavement layer,sensors are embedded in the in-situ pavement layer to collect data on the axle load,pavement temperature and strain of the tunnel asphalt pavement layer.Subsequently,the control variable method was adopted to analyze the influence laws of the axle load,vehicle speed and pavement temperature on the pavement strain at different structural layers.The results show that the bottom strain of the upper tunnel pavement layer presents an alternating"compression-tension-compression"pattern,while the bottom strain of the lower tunnel pavement layer is dominated by a"compression"pattern.This characteristic is distinct from the tension-dominated response observed at the bottom of asphalt pavement with semi-rigid base courses.The axle load,vehicle speed and pavement temperature exert significant impacts on the strain of the tunnel asphalt pavement layer.Specifically,an increase in the axle load,a decrease in the vehicle speed and a rise in the pavement temperature all contribute to the growth of pavement strain.Statistical fitting of measured data under fixed boundary conditions shows that pavement layer strain exhibits a good linear fitting relationship with the axle load and vehicle speed,and conforms to an exponential function fitting relationship with the pavement temperature.Furthermore,this study explores the variation law of strain response of the tunnel pavement layer under the coupling effect of multiple factors,and establishes a multivariate correlation regression model between the tunnel pavement strain,axle load,vehicle speed and pavement temperature,with a remarkable regression effect.The research findings can provide theoretical and technical support for understanding the strain variation law of tunnel asphalt pavement layers under actual service conditions.