Design grading method for improving skid resistance of asphalt overlay and supplementary sieve pores

The invention relates to a design grading method for improving the skid resistance of an asphalt overlay and a supplementary sieve pore. In order to design the asphalt surface layer mixture with better anti-skid performance, supplement sieve pores with different sizes are introduced between 4.75 mm sieve pores and 9.5 mm sieve pores, and the skeleton dense type asphalt surface layer mixture is designed. According to the method, a virtual asphalt mixture test piece is constructed based on PFC2D, coordination number and average contact force of mixtures of different grades are analyzed, aggregate grading coordination number and coordination number contribution rate as well as grading average contact force and average contact force contribution rate are analyzed, and the skeleton performance of the mixture is evaluated. After the index value of each skeleton structure is comprehensively analyzed, the optimal supplementary mesh size of a single supplementary mesh is 8mm, and the optimal supplementary mesh size of