a The 10000 lb load is applied on a set of dual tires b Tire

a. The 10,000 lb load is applied on a set of dual tires.
b. Tires are spaced at 14 inch on centers.
c. Slab thickness is 10 inch.
d. Subgrade modulus (k) is 100 pci.
e. Other conditions can be assumed if needed.

Figure 2 Plan view of concrete slab under a set of dual tires

Solution

Solution:-

Given

P =10000 lb

h = 10 inch

K =100 pci

Let µ =0.15

Let E = 4.26 *10⁶ pound/inch²

a = 14 inch

Radius of relative stiffness(l) = (Eh³/(12K(1 - µ²)))^(1/4)

                                                      = (4.26*10⁶*10³/(12*100*(1 – 0.15²)))^(1/4)

                                                   = 43.65 inch

We know that

b = (1.6a² – h²) - 0.675h

= (1.6 * 14² -10²) – 0.675 *10

b = 7.86 inch

Stress(_i) = 0.316 P/h² *( 4 log₁₀(l/b) + 1.069)

                 = 0.316 * 10000/10² *(4 log₁₀(43.65/7.86) + 1.069)

Stress(_i) = 127.89 lb/inch²    Answer