Load-Transfer Criteria for Numerical Analysis of Axially Loaded Piles in Sand. Part 1. Load-Transfer Criteria


Book Description

Part I describes a study of load-transfer criteria for analysis of axially loaded piles in sand using the discrete springs soil model. Various analysis methods for axially loaded piles are presented, along with a literature review of pile behavior in sands focusing on the changes the soil undergoes during pile installation. Available criteria for spring representation of soil are presented and summarized. The criteria are compated with actual field data from pile load tests and are critically evaluated based on these comparisons. Because of the poor performance of the available criteria, new criteria are proposed. The new criteria use maximum side and tip resistance values presented by Castello (1980). Castello's values are modified by the author to reflect the field data from the Lower Mississippi Valley. Displacement functions for side and tip resistance are developed based on correlations with field data for pile load tests. The new criteria are evaluated against pile load test data. Use of the critieria is demonstrated in an outline of an analysis. The new criteria are used to develop a set of design curves for the practicing engineer. Part II of this report is published under a separate cover, and presents load capacity curves for select steel and concrete pile.




Load-Transfer Criteria for Numerical Analysis of Axially Loaded Piles in Sand. Part 2. Load Pile Capacity Curves for Steel and Concrete Piles


Book Description

This report presents load capacity curves for the design and analysis of axially loaded piles. A brief discussion of the contents of this report and the applicability of the curves follows. In order to make intelligent use of these curves, the reader should have a through knowledge of the criteria used in their development. These criteria are presented in Part I of this report.



















Fundamentals of Earthquake Engineering


Book Description

Fundamentals of Earthquake Engineering: From Source to Fragility, Second Edition combines aspects of engineering seismology, structural and geotechnical earthquake engineering to assemble the vital components required for a deep understanding of response of structures to earthquake ground motion, from the seismic source to the evaluation of actions and deformation required for design, and culminating with probabilistic fragility analysis that applies to individual as well as groups of buildings. Basic concepts for accounting for the effects of soil-structure interaction effects in seismic design and assessment are also provided in this second edition. The nature of earthquake risk assessment is inherently multi-disciplinary. Whereas this book addresses only structural safety assessment and design, the problem is cast in its appropriate context by relating structural damage states to societal consequences and expectations, through the fundamental response quantities of stiffness, strength and ductility. This new edition includes material on the nature of earthquake sources and mechanisms, various methods for the characterization of earthquake input motion, effects of soil-structure interaction, damage observed in reconnaissance missions, modeling of structures for the purposes of response simulation, definition of performance limit states, fragility relationships derivation, features and effects of underlying soil, structural and architectural systems for optimal seismic response, and action and deformation quantities suitable for design. Key features: Unified and novel approach: from source to fragility Clear conceptual framework for structural response analysis, earthquake input characterization, modelling of soil-structure interaction and derivation of fragility functions Theory and relevant practical applications are merged within each chapter Contains a new chapter on the derivation of fragility Accompanied by a website containing illustrative slides, problems with solutions and worked-through examples Fundamentals of Earthquake Engineering: From Source to Fragility, Second Edition is designed to support graduate teaching and learning, introduce practising structural and geotechnical engineers to earthquake analysis and design problems, as well as being a reference book for further studies.




Recommendations


Book Description

This report presents a comprehensive evaluation of load-transfer criteria for analysis of axially loaded piles in clay. The US Army Corps of Engineers installs thousands of piles each year in the construction of navigational and flood control structures. So that these structures will perform satisfactorily, not only must the capacity of the pile foundations be adequately determined but the load-deformation behavior of the foundation must also be predicted to allow an analysis of the structure for stresses and deformations. Various predictive methods for computing side resistance capacity and shear transfer versus vertical pile movement, f-z curves for clay are presented. Parametric studies were conducted to determine the method that could best represent pile behavior. Instrumented pile loads were used to evaluate the performance of the methods under actual field conditions. Based on these investigations, procedures for determining side resistance and shear transfer versus vertical pile movement are recommended. Keywords: Pile structures; Structural foundations; Axial loads.