1. A 9,000-lb single wheel load is placed on a PCC slab that is 9.5 in. thick. The concrete has a modulus of elasticity of 5 million psi with a Poisson’s ratio of 0.15. The modulus of subgrade reaction is 225 pci. Tire pressure is 90 psi.
(a) Calculate the maximum bending stress if the load is placed at the interior of the slab, assuming the shape of the loaded area is: (i) A circle; (ii) A square. Comment on the practical significance of the discrepancy between the two solution sets.
2.Solid waste production in the United states was 4.3lbs/person-day. Calculate the potential methane production in one year for a land fill that serves a community of 50,000 people. Assume that none of the solid waste is recycled, that all the solid waste can decompose rapidly, and that the density of methane equals 0.717kg/m cubed