Cyclic lateral load behaviour of piles

Technical Abstract

The non linear soil model proposed by Pender is represented in this thesis based on an initial small strain stiffness, a yield pressure and an index "n". Carter (1984) wrote a finite element program to predict the static lateral load behaviour of piles using this model and found that this simple model gave similar standard of accuracy to the responses predicted using the p-y curves. Ling (1988) verified this fact.

The author used the same model to predict the cyclic lateral load behaviour of piles modifying the finite element program written by Carter (1984). Some full scale pile test results are presented to verify the validity of the soil model. This mode was found to be a valuable tool for its simplicity and accuracy for cyclic loads as well.

The permanent set created in unloading cycles were achieved by stiffening soil springs in the unloading cycles i.e. increasing yield pressure in the soil model.

The cyclic degradation of soil was considered which is a function of number of cycles and the deflection of the pile in the previous loading cycle.