Key words: tapered piles, lateral response, p-y curves, modulus of subgrade reaction.

Key words: plate-load test, gravelly cobble deposit, modulus of subgrade reaction, bearing capacity.

The modulus of subgrade reaction is of particular importance in the local practice of designing high-rise buildings on mat foundations.

The Modulus of subgrade reaction (ks) is used in foundation design, soil-structure interaction studies and design of highway pavements.

The backfill material was approximated by linear compression springs with spring constants directly related to the experimentally determined modulus of subgrade reaction.

The field Plate Load Test is commonly used to predict the deformations and failure characteristics of the soil/subgrade and modulus of subgrade reaction (ks).