Calculation of Modulus of Subgrade Reaction

Modulus of subgrade reaction or coefficient of subgrade reaction is the reaction pressure sustained by the soil sample under a rigid plate of standard diameter per unit settlement measured at a specified pressure or settlement. It is a stiffness parameter that is commonly used to define the support conditions of footings and mat foundations. This parameter explains a linear elastic response. Hence during the design, the pressure generated by the modulus of subgrade reaction is limited to the allowable bearing pressure of the soil. The coefficient of sub-grade reaction (k) is the primary parameter used in the design of pavements, foundation, and soil-structure interaction studies.