Moments and Reactions for Rectangular Plates

This report documents two studies that were conducted to review, assess, and provide recommendations regarding the seismic design of bridge foundations. Specifically, the report addresses modeling approaches and parameters that affect the seismic design and response of pile groups and drilled shafts. The report attempts to bridge the interface between the structural and geotechnical design process by describing a two-step design and analysis procedure for these bridge foundation components. Recent research results on pile group effects and the design of pile foundations to resist lateral spreading of liquefiable soils are also reviewed. Recommendations are provided concerning: modifications to p-y curves to account for cyclic loading conditions, pile group effects and soil-pile interaction behavior, and development of p-y curves for the design of drilled shafts. 

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Moments and Reactions for Rectangular Plates
http://www.usbr.gov/pmts/hydraulics_lab/pubs/EM/EM27.pdf

Mohr Circles, Stress Paths and Geotechnics

 

The second edition of this well established book has been comprehensively updated in line with recent developments. After presenting the fundamentals of stress and strain, and their graphical representation, the book includes chapters on failure states in soils and rocks, observed and elastic paths, and the use of discontinuities.

New sections include shear bands and small strain behaviour, as well as the use of elastic shear modular stress calculations and discontinuities in plasticity calculations. Expanded coverage is also given to dilitancy of soils and roughness of rock joints.

 

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Mohr Circles, Stress Paths and Geotechnics
http://www.4shared.com/file/2L3A56gT/Mohr_Circles_Stress_Paths_and_.htm
http://www.4shared.com/file/Kj70LZIT/Mohr_Circles_2C_Stress_Paths_a.html

Modification of LRFD Resistance Factors Based on Site Variability

Current practice by the Florida Department of Transportation (FDOT), Federal Highway Administration (FHWA), and American Association of State Highway Transportation Officials (AASHTO) for deep foundation design is to use a constant load and resistance factored design (LRFD) Φ depending on redundancy, but independent of pile/shaft dimension. Unfortunately, soil/rock properties vary from point-to-point (CVq: coefficient of variation) and are typically spatially correlated. Since both the skin friction and end bearing involve spatial averaging of soil/rock properties over the shaft surface, the resulting total shaft resistance variability (CVR) will not share the same point variability (CVq). Moreover, the total shaft variability (CVR) will also vary with different degrees of spatial correlation, typically represented with a covariance function and a correlation length a. This work employs well established geostatistical principles to establish both the covariance function (e.g., variogram) and expected total pile/shaft variability (CVR) using borehole data. Consideration is given to the number of borings, the location of borings relative to each other, and to the design foundation (e.g., if the borings are within the footprint of the design pile/shaft). Since the resulting pile/shaft variability CVR is a function of pile/shaft dimensions, soil/rock variability CVq, and its spatial correlation, the resulting LRFD Φ is not constant for any site. To help the designer, four quadrant iterative design charts are developed for single and group pile/shaft layouts, which consider side and tip resistances, as well as layered systems. To better define the total pile/shaft variability CVR, the practice of load testing is also incorporated into the proposed approach. The work includes multiple design examples and data from existing FDOT bridge sites (e.g., 17th Street, Fuller Warren, and Jewfish Creek bridges). 

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Modification of LRFD Resistance Factors Based on Site Variability
http://www.dot.state.fl.us/research-center/Completed_Proj/Summary_SMO/FDOT_BD545-76_rpt.pdf

Modelling of Soil-Structure Interaction

 

Distributed in the East European countries, China, Northern Korea, Cuba, Vietnam and Mongolia by Academia, Prague, Czechoslovakia This book is based on the efficient subsoil model introduced by the authors in 1977 and applied in the last ten years in the design of foundations. From the designer's point of view, the model considerably reduces the extent of the calculations connected with the numerical analysis of soil-structure interaction. The algorithms presented are geared for use on mini- and personal computers and can be used in any numerical method. A special chapter is devoted to the implementation of the model in the NE-XX finite element program package, illustrated with diagrams, tables and practical examples. Besides presenting the energy definition and general theory of both 2D and 3D model forms, the book also deals with practical problems such as Kirchhoff's and Mindlin's foundation plates, interaction between neighbouring structures, actual values of physical constants of subsoils and natural frequencies and shapes of foundation plates. Today, researchers and engineers can choose from a wide range of soil models, some fairly simple and others very elaborate. 

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Modelling of Soil-Structure Interaction (Developments in Geotechnical Engineering vol. 58)

http://www.2shared.com/file/AX5uvspL/Modelling_of_Soil-Structure_In.html

Modeling Soil Liquefaction Hazards for Performance-Based Earthquake Engineering

 

The performance of structures such as buildings and bridges during earthquakes is strongly
influenced by the performance of the soils that support them. Local soil conditions can influence structural performance in two primary ways by influencing the ground motions that excite the structure and by imposing additional deformations on the structure through ground failure. The first widespread observations of damage attributed to liquefaction were made in the 1964 Niigata, Japan, and 1964 Alaska earthquakes. In numerous earthquakes since, liquefaction has been deemed responsible for significant damage to buildings and bridges. Liquefaction has been studied extensively over the past 35 years, and substantial advances have been made in understanding the development and effects of this phenomenon. These advances have led to a series of practical procedures for evaluating the potential for occurrence and for estimating its effects. These procedures, however, are almost entirely empirical in nature and, as such, are difficult to apply to the problem of performance prediction for individual structures. The Pacific Earthquake Engineering Research (PEER) Center is committed to the development of methods and procedures for performance-based earthquake engineering (PBEE). The use of PBEE requires the ability to predict a nearly continuous spectrum of performance states for individual structures. This requirement implies the need for tools and procedures for evaluation of the entire process of liquefaction, from initiation to effects. Recent advances in the understanding of liquefaction-related phenomena offer the promise of improved analytical predictions of the initiation and effects of soil liquefaction.

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Modeling Soil Liquefaction Hazards for Performance-Based Earthquake Engineering
http://peer.berkeley.edu/publications/peer_reports/reports_2001/0113.pdf

Modeling of Pile Footings and Drilled Shafts for Seismic Design

This report documents two studies that were conducted to review, assess, and provide recommendations regarding the seismic design of bridge foundations. Specifically, the report addresses modeling approaches and parameters that affect the seismic design and response of pile groups and drilled shafts. The report attempts to bridge the interface between the structural and geotechnical design process by describing a two-step design and analysis procedure for these bridge foundation components. Recent research results on pile group effects and the design of pile foundations to resist lateral spreading of liquefiable soils are also reviewed. Recommendations are provided concerning: modifications to p-y curves to account for cyclic loading conditions, pile group effects and soil-pile interaction behavior, and development of p-y curves for the design of drilled shafts. 

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Code

Modeling of Pile Footings and Drilled Shafts for Seismic Design
http://ntl.bts.gov/lib/22000/22000/22044/PB99157257.pdf