The Fast Inversion Research Of Airport Pavement Deflection Curve Based On Winkler Foundation

The inversion of pavement structure parameters in airport engineering is an important basis for judging the airport pavement bearing capacity and the reinforcement of pavement structure performance based on the deflection curve of HWD tests.Therefore,it is important to improve the accuracy and inversion efficiency of pavement structure parameter inversion results.Therefore,this paper proposes a fast inversion method of pavement structure parameters based on the deflection curve.The main research contents and results are as follows:1.Using the soft of ABAQUS,a finite element calculation model of rigid pavement with HWD testing was established based on the Winkler foundation,and the finite element calculation results were verified through theoretical calculation.Moreover,the boundary conditions of the model is optimized,and the secondary development is carried out based on the optimized finite element model to realize the automatic construction of the HWD test deflection database of the rigid pavement under different parameter combinations,which provides the search for the inversion of the pavement structure parameters based on the database.2.The factors influencing of the deflection curve was studied to obtain the influence law of each influencing factor on the deflection curve.Meanwhile,the surface structure parameters are not only affect the deflection value of each measuring point of the deflection test,but also affect the deflection curve shape and trend.It is proposed that the process of inversion of pavement structure parameters is not only the difference in deflection value of each point,but also the difference between the shape of the inversion deflection curve.Thereby,the measured shape of the deflection curve should be paid attention to.Rules for data filtering and convergence in the process are analyzed.3.In this study,a rapid inversion method of road surface structure parameters is proposed based on database search.The core idea of this method is based on the deflection curve of HWD test.The exhaustive method is used to compare the similarity between the measured and theoretical deflection curve in the database one by one.Using the comprehensive discriminant method of Euclidean distance and cosine similarity,it not only considers the difference in deflection value,but also pays attention to comparing the shape of the deflection curve.The process of inversion really makes full use of the information of each measurement point.The reliability and accuracy of the inverse calculation results are analyzed.The analysis results show that the inversion results have good reliability and accuracy.Under the condition of introducing measurement errors,the inversion deflection value differs at most 8%.4.The software of fast inversion of road surface structure parameters was written in Python language,and the software was used to calculate the measured deflection data of a 4F airport in South China.The inverse calculation results show that the inverse calculation method is basically the same as the actual measured deflection curve,and the inverse elastic modulus of the road surface is not much different from the laboratory test results compareing with the standard recommended.The deflection basin area index method has significantly improved both the accuracy of the back calculation results and the back calculation efficiency.