Initial Monitoring And Analysis On Dynamic Response Of Pavement Structure

The traditional tests for pavement structural response are difficult to obtain information of actual mechanical condition under vehicle load coupled with environmental factors, so it can't help for pavement structural design and evaluating to pavement performance. On the contrary, achieving timely collection and analysis of internal information of pavement structure is used not only to verify the pavement structural design and calculation to ensure the unity of design and physical construction, but also analyzing the structure response of asphalt pavement that is help for clarifying the damage mechanism of the asphalt pavement and estimating life of pavement, then a reasonable road maintenance program would be made.As a result, it analyzed the characteristics, evaluation parameters and key position of pavement distress, then a monitoring system for the dynamic response of pavement was designed and implemented partly, that was based on fiber Bragg grating sensing technology. At the same time, fatigue performance of materials in laboratory was studied here to predict fatigue life of actual pavement based on the current progress of the work.Firstly, it carried out design, implementation and preliminary analysis for the data of pavement structural dynamic response monitoring system. Based on analyzing reasons and common characteristics of pavement distress, the important positions and parameters of road were determined for the system. Then some sensors of the system was selected and buried in the road according to work, use methods and position of the sensors. What's more, the results of pavement structure response information on-site, which from different speeds, different weights and different layers of pavement, has been preliminary analyzed.Secondly, aiming at calibrating the sensors, strains from different tests were obtained and analyzed based on small-scale test. It developed buried methods that using resistive strain gauge and fiber Bragg grating sensor in a rutting specimen according to their testing theories and affecting factors. Then the regression relationship between them was built. At the same time, it compared test strain with theory strain of beam in the three-point bend test in order to calibrate the gauge. Based on the above two steps, the calibration formula of information from fiber Bragg grating sensors was established.Finally, preliminary study on fatigue life of pavement structure against fatigue damage of asphalt pavement, which based on the level of strain, was carried out. At the same time, fatigue equation was established, and the prediction method of fatigue life was also given based on three-point bending fatigue test according to the dynamic response information of the road.