Study On The Technology Of Road Deflection And Bearing Capacity Under Moving Traffic

Deflection is one of the important parameters reflecting the overall road distortion, and is the reference of construction quality control and road maintaining and evaluation. Deflection testing technology is vary from the initial Beckman beam technology, through the automatic deflection, falling weight deflection, and the most advanced laser deflection technique. But the work efficiency of Beckman beam technology is low, the security reliability of Automatic deflection and falling weight deflection is poor, and the Laser deflection technology is expensive and its result is still unproven. So the road deflection and bearing capacity test method under moving traffic puts forward. Combined with the theoretical research of road-car coupling response model, numerical simulation and building the relative model, the road carrying capacity evaluation is realized through placing intelligent sensor on somewhere having no effects on moving vehicle and have wonderful effects on reflecting the characteristics of the road to collect datas. Under supporting of the Hebei Province Communication Science Funds, the main research conclusions are as follow:1. The different roughness grade roads of A, B, C, D is generated by ANSYS. And the vehicle model is established based on vehicle dynamics equations. Finally, the vehicle loads of different working conditions is derived with the roughness of A, B, C, D.2. Based on the two pavement layer model, the road model is generated by ANSYS. Then the road-car coupling response model is established with putting the vehicle loads on the road model.3. Based on the existing road-car coupling response model, the deflection effects of axle load, driving speed, structure layer thickness and structure layer modulus is studied. Then the deflection calculation formula of A, B, C and D roughness grade roads is established through a large number of finite element trial and orthogonal experiment. Finally the analysis model of equivalent modulus of elasticity is built and the road carrying capacity evaluation is completed combined with the classification standard of road bearing capacity.4. Based on HTML and JAVASCRIPT platform, the software of road carrying capacity evaluation and deflection is written. The target of road carrying capacity evaluation is obtained by writing the value of measured deflection data.5. In order to using the research achievement to a new built road, the measured deflection data is obtained by the filtering and integral acceleration signal. Then the measured deflection data is calculated by software to obtain the equivalent modulus of elasticity(240.93179 MPa) and the target of modulus(0.93006). The measured data and the design data of equivalent modulus of elasticity is similar and the error between them is about 7%.Finally, the reliability and effective of the analysis model is verified by engineering example.