The Research Of Pavement Structure Analysis System Based On The Deflection

HWD(Heavy Weight Deflectometer) deflection test is the most important technical means to test and analyzes pavement structural performance. Because of the very short history of HWD testing technology introduced into our country, especially in the field of civil aviation airport, so the test theory and method, the reliability of the test results are lack of systematic research, and these problems have been hot spots on engineering and academia. Based on the above background, this paper has carried out the following work:Firstly, this paper has carried on theoretical analysis and experiment validation on the deflection basin area parameters method, then corrects the method. Through the comparison and analysis about deflection basin area parameters method adopted by our country civil airport with four main kinds of international similar method using U.S. NAPTF(National Airport Pavement Test Facility) model runway’s deflection data, the results show that reaction modulus of foundation analyzed by deflection basin area parameters method of our country is 35% maximum higher than the actual value. For these problems such as the contradictory theory relationship and unreasonable formula form between deflection basin area parameters and radii of relative stiffness, radii of relative stiffness and deflection coefficient on load center, this paper has carried out numerical calculation and analysis about the theoretical relationship between deflection basin area parameters and radii of relative stiffness, radii of relative stiffness and deflection coefficient on load center based on the theory of elastic foundation plate. And then it revised the current empirical formulas in our country. The results show that the maximum error of reaction modulus of foundation analyzed by the revised deflection basin area parameters method is 16.7%.Secondly, this paper has carried on the experimental test and analysis about the reliability of HWD test method. The different testing results range of different deflection testing equipments are analyzed by using the model pavement’s deflection data released by the United State airport test centers NAPTF. The analysis mainly includes impact stiffness modulus(ISM), load transfer efficiency of joints and reaction modulus of foundation, the fluctuation range of which are-13.7% ~ 13.7%,-28.5% ~ 10.9% and-44.5% ~ 62%. Combining with the actual pavement’s deflection data, this paper systematically analyzes the deflection test error. The results show that the influence of the fluctuation range of the error to impact stiffness modulus(ISM), load transfer efficiency of joints and reaction modulus of foundation are-8.5%~ 33.9%,-21.8% ~ 20.1% and-54.2% ~ 51.2%. According to the influence on test results of these two factors, this paper makes the uniformity quantitative evaluation indices.Thirdly, to solve the defect that plate edge bending moment influence diagram cannot apply to B777 and A380 series and other large wide-body jets, and to maintain the merits of suitable for repeated trial, simple principle and convenient for engineers to accept, this paper analyzes the relevant relationships between total weight of aircraft, radii of relative stiffness and plate edge bending moment by using finite element method. Then on this basis, the author draws calculated curves of plate edge bending moment on common civil aircraft.