The Study Of Analyzing And Evaluating Methods For Asphalt Overlay's Reliability

Recently, asphalt overlay on asphalt pavement as a means of maintenance or reconstruction have been widely applied, but the problem of ahead failure is severity. Based on the advisement of economy and availability, how enhance asphalt overlay's reliability and make it concentrative failure have been one of emphasises for scientific research of pavement.According to the specifications for design of highway asphalt pavement (JTJ 014-97), establishing two utmost state equations based on the deflection and positive stress. By contrastively analyzing the advantage and disadvantage of approximate methods for pavement structure's reliability, it was found that Monte Carlo method has a good applicability for asphalt overlay, then introduced some sample methods for stochastic variable and ascertained sample number.By optimal analysis, it was found that equivalent elastic modulus of old pavement has a remarkable influence on deflection and positive stress, so we know asymmetric strength worthy of recognition. According to numbers of sample, using W and D methods to checkout the distributing style of some design and traffic parameter, thereby, supplying convenience for Monte Carlo simulation. Then the rules of asphalt overlay's reliability was analyzed along with equivalent elastic modulus of old pavement, thickness and modulus of overlays.The traffic load is an important factor when design the pavement structure, asymmetric distribution of the traffic load has a remarkable influence on asphalt overlay's reliability similarly. Based on the analysis of variability of traffic load parameter, we gained some rules between asphalt overlay's reliability and accumulative equivalent axle-times under two control indexes. Besides, the attenuation trend of asphalt overlay along with service year was analyzed by using methods of probability.Using t test, a section of asphalt overlay can be partitioned some cells, these cells was basal parts for composing system net. After analyzing failure process, cause and model, the evaluating method was elementarily explored and simply validated with instance.