ABSTRACT:

For many years, civil engineers have considered that piles could only support loads applied in line with their central axis. As a result, piles required to resist lateral forces, were installed at a batter. However, it is now realized that the lateral resistance of vertical pile is considerable. Obviously, interactions between the pile and the surrounding soil should be considered both in the design and analysis of the structural system (superstructure and pile-foundation) subjected to lateral actions. In this paper, a displacement-based frame fiber model with continuous lateral deformable soils is used to represent the pile-foundation of frame buildings. The proposed model is simple, computationally efficient and capable of representing the salient features of the soil-pile interaction. The example of an end-bearing cast-in-place pile embedded in the cohesionless soil (sand) is used to investigate the effects of soilpile interaction on the response of pile-soil systems. An inelastic finite element analysis is performed to investigate the effects of model parameters on the pile-soil response. Several model parameters (e.g. pile length, pile cross-section geometry, pile and soil nonlinearities) are examined. The parametric studies show that the nonlinearity of the surrounding soils and geometric properties of the pile greatly affect the responses of the pile and the position of the plastic hinge in the pile. Under cyclic loadings, the dragging and gapping features of the surrounding soil are crucial in describing the hysteretic behaviour of the pile-soil system.

INTRODUCTION

Nowadays, structural engineers are challenged to design and investigate expensive and strategic structures (e.g. high-rise buildings, offshore platforms, multi-story highways etc.) for extreme lateral loadings. Usually, pile foundations are used to support these structures. Consequently, the inclusion of the soil-pile system into the numerical model is crucial for design and analysis of these structures under extreme events.

This content is only available via PDF.
You can access this article if you purchase or spend a download.