5. A 3-layer flexible pavement is subjected to a single circular wheel load as shown in the figure. The table below shows the stresses and strains at the given coordinates obtained from a layered elastic structural analysis. If the pavement is subject to 1,500 repetitions of the wheel load per year, what would be the expected life of the pavement based on the performance failure criteria given below for fatigue cracking and rutting? Layered Elastic Stress/Strain Analysis Results COORDINATE (in.) STRESS (psi) Radial Vertical Vertical Radial Tangential 0.00 5.75 56.92 -523.80 -523.80 0.00 28.75 11.93 1.28 1.28 Shear 0.00 Vertical 1.45E-3 1.06E-3 STRAIN Radial Tangential -7.26E-4 -7.26E-4 -5.32E-4 -5.32E-4 Shear 0.00 0.00 0.00 Performance failure criteria N= 0.0796(&)-3.291 (E_) -0.854 for fatigue cracking Na = 1.365 x 10-'(c)-4477 for rutting 40,000 lb 1 150 psi E, = 400,000 psi, V = 0.50 20 = ? 5.75 in. E = 20,000 psi, V = 0.50 23 in. .? E = 10,000 psi, V-0.50 5. A 3-layer flexible pavement is subjected to a single circular wheel load as shown in the figure. The table below shows the stresses and strains at the given coordinates obtained from a layered elastic structural analysis. If the pavement is subject to 1,500 repetitions of the wheel load per year, what would be the expected life of the pavement based on the performance failure criteria given below for fatigue cracking and rutting? Layered Elastic Stress/Strain Analysis Results COORDINATE (in.) STRESS (psi) Radial Vertical Vertical Radial Tangential 0.00 5.75 56.92 -523.80 -523.80 0.00 28.75 11.93 1.28 1.28 Shear 0.00 Vertical 1.45E-3 1.06E-3 STRAIN Radial Tangential -7.26E-4 -7.26E-4 -5.32E-4 -5.32E-4 Shear 0.00 0.00 0.00 Performance failure criteria N= 0.0796(&)-3.291 (E_) -0.854 for fatigue cracking Na = 1.365 x 10-'(c)-4477 for rutting 40,000 lb 1 150 psi E, = 400,000 psi, V = 0.50 20 = ? 5.75 in. E = 20,000 psi, V = 0.50 23 in. .? E = 10,000 psi, V-0.50