UBC Theses and Dissertations
Modelling of single vertical piles subjected to monotonic and cyclic lateral loads and free-field movements Vazinkhoo, Saman
In the past twenty years, many researchers and practitioners have become interested in the behaviour of piles under lateral loading conditions. Although piles are generally used to carry axial loads, quite often, such as in the case of seismic loads and/or lateral loads caused by ground displacement, they are required to carry lateral loads. The ability to predict the performance of piles under lateral loading caused by earhquakes is very important and is the focus of this thesis. To date very few and limited modelling techniques have been developed based on data obtained from testing of full size piles. This is due to the high costs involved with performing comprehensive experiments on prototype piles. The response of piles to lateral loads may be analyzed using different methods ranging from complex 3-D finite element techniques to simple closed-form solutions for an elastic beam on an elastic foundation. This thesis employs the modulus of subgrade reaction approach due to its versatality and ease of use. In the last five years, large amount of data from pile lateral load tests have become available. In this thesis, the available methods and models for analysing laterally loaded vertical piles are first reviewed and then two new models are developed. The first is a new cyclic P-y curve model based on the Hydraulic Gradient Similitude (HGS) tests carried out by Yan (1990). Then a new numerical model is developed which incorporates the first model and other P-y curves for analysis of laterally loaded vertical piles. The new numerical model is incorporated into the computer program CYCPILE which is calibrated and verified using the available test data. In general, excellent agreement between the model predictions and the test data is obtained.