Analysis of Piles in Liquefying Soils by the Pseudo-Static Approach

Abstract

AbstractThe pseudo-static method of analysis is a simplified design-oriented approach for analysis of seismic problems based on routine computations and conventional engineering models. The application of the method to analysis of piles in liquefying soils is burdened by significant uncertainties associated with soil liquefaction, soil-pile interaction in liquefying soils and the need to reduce a very complex dynamic problem to a simple equivalent static analogy. Hence, despite its simplicity, the application of the method is not straightforward and requires careful consideration of the uncertainties in the analysis. This chapter addresses some of the key issues that arise in the application of the pseudo-static analysis to piles in liquefying soils, and makes progress towards the development of a clear modelling (analysis) strategy that will permit a consistent and reliable use of the simplified pseudo-static analysis.A comprehensive parametric study has been conducted in which a wide range of soil-pile systems, loading conditions and values for model parameters were considered. In the analyses, the pile responses during the strong ground shaking (cyclic phase) and post-liquefaction lateral spreading were considered by two separate pseudo-static analysis approaches. Results from the analyses are used to examine and quantify the sensitivity of the pile response to various model parameters, and to establish a fundamental link between the sensitivity of the response and the mechanism of soil-pile interaction. On this basis, some general principles for ­conducting pseudo-static analysis of piles in liquefying soils can be established irrespective of the specific properties of the soil-pile system and loading conditions.KeywordsLateral SpreadingExcess Pore PressureGround DisplacementInertial LoadPile HeadThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.