Analysis of non-linear soil-pile interaction under dynamic lateral loading.

摘要

The present study investigates the response and behavior of single piles in layered soil deposits under dynamic lateral loading, and identifies the major parameters affecting the soil-pile interaction. Primary attention is focused on the effects of localized nonlinearities such as the formation of gaps between the soil and the pile, permanent soil deformations in the vicinity of the pile, and the inelastic cyclic stress-strain behavior of the soil.; The main objective of this research is to develop a three-dimensional computer model capable of simulating the complex cyclic paths of soil-pile interaction under dynamic lateral loading, considering the effects of nonlinear hysteretic soil behavior and the soil-pile separation. The program includes the following features: (1){A0}Implementation of the Hu-Washizu variational principle to accurately model the pile bending with a relatively coarse mesh. (2){A0}Modeling of the behavior of cohesive soils and its cyclic response for different degrees of over-consolidation ratios and initial states through the implementation of bounding surface plasticity model within the framework of critical state soil mechanics. (3){A0}Simulation of the interface behavior to model gap formation between the soil and the pile using a penalty formulation for enforcing the contact constraints. Of particular concern is the formulation of a constitutive model which fully complies with all possible histories of opening, closing and sliding in any direction. (4){A0}Representation of the radiation condition to account for waves propagating from the structure-medium interface towards infinity in a soil-structure interaction analysis using transmitting boundaries to reproduce approximately the far field effect.; In addition, various geotechnical loading and boundary conditions including drained and undrained loading, water table, in-situ stresses and preconsolidation have been included. Results are compared with available theoretical solutions, and with results from both full-scale and reduced-scale pile load tests.