2 Calculate the Effective Modulus of Subgrade Reaction k per

2. Calculate the Effective Modulus of Subgrade Reaction (k) per Table 3.2 of the 1993 AASHTO Rigid Pavement Design Guide for the pavement configuration given in Figure 1 and for the seasonal subgrade soil data given in Table 1. You must make appropriate corrections for depth to bedrock and loss of support (Use LOS = 1.0). Use a Subbase resilient modulus of 75 ksi and assume that there is no seasonal variation of subbase strength. Eigure 1 8\" thick Concrete Slab 6\" thick Cement Treated Base 10 feet thick subgrade Bedrock Table 1. Seasonal variation of subgrade resilient modulus No. Seasonal Period 1 December - February 2March- April 3May - November Subgrade Resilient Modulus (ksi) 20 7.2 12

Solution

Modulus of subgrade reaction(K)=load(In Kg)÷penetration(In cm)

And use this formula and get the effective subgrade of reaction