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Jae H. Chung, Ph.D. and Henry T. Bollmann, P.E.Bridge Software Institute

University of FloridaGainesville, Florida

June 11, 2014

FB-MultiPier Update

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Agenda

• Part I: FB-MultiPier New Features of Upcoming Releases and Medium-Term Development (presented by Jae Chung)

• Part II: Use of Design Tables and Model Showcase

(presented by Henry Bollmann)

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Bridge Software Institute (BSI) Products

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FB-MultiPier Software Program

• Nonlinear Finite Element Analysis Tool for Use in Bridge Design Application• Material nonlinearity and large-deformation (p-delta effect) can be

analyzed using a 3-D frame finite element formulation coupled with soil resistance (4 nonlinear soil springs per each node of FE structure frame).

• Quasi-static and dynamic analyses can be performed either separately or simultaneously.

• Simplified input process in geometric definition of pier components and automated FE mesh (structural skeleton) generation saves time and makes it easy for model calibration.

• Biaxial Moment-Interaction Diagram and easy-to-use materials modeling options are a few to mention.

• Analysis capabilities of coupled soil-structure interaction is the main strength of the program.

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• Flexure • Max positive moment

• Max negative moment

• Shear• Max magnitude shear force

• Force Envelopes • Across all load cases

• Per load case

Features for Upcoming Releases:Pile Cap Summary Forces (V4.19.1)

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• Pile Cap Summary Force Calculations

Pile and cap model Load Case 1 Load Case 2

Illustration of Pile Cap Summary Forces (V4.19.1)

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Pile Cap Summary Forces (V4.19.1)

• 3D results

• Graphical selection of section

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Features for Upcoming Releases: One-Pier Two-Span Model (V4.20)

• Simplified Bridge Model for Dynamic Analysis • A single pier of interest

• Two Adjacent Spans

• 6 DOF’s discrete springs are at both ends of the two adjacent spans

FB-MultiPier schematic representation of a 7-pier configuration

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Illustration of OPTS Model

• Multiple-pier model of SR-20 Apalachicola River Bridge• Eastern channel pier (Pier 59) subjected to lateral dynamic loading

Source: Google maps

N

Source: Google maps

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FB-MultiPier Analysis• Seven-Pier model of SR-20 Apalachicola River Bridge

• Lateral dynamic load on Pier 59

4 sec simulation in 112 min.

Pier 59

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59

4 sec simulation in 5 min.

FB-MultiPier Analysis Model

• OPTS modeling approach• Lateral dynamic load on Pier 59

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Comparison of Analysis Results

• Lateral displacement prediction

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Analysis Results

• Comparison of 7-pier model vs OPTS• 2% difference in maximum D/C values

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 2

D/C

Val

ues

Full-bridge

OPTS

Pier columns Drilled shafts

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Thermal Load Effects in Piers (V4.21)• Implemented in Beta Version of FB-MultiPier

• Can generate AASHTO TU, TG reactions at bearings

FB-MultiPier GUI

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Superstructure Configuration (V4.21)

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Uniform Temperature Loading: TU (V4.21)

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Thermal Gradient Loading: TG (V4.21)

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Span-Thermal Loading : User’s Option (V4.21)

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AASHTO Span-Thermal Loading : User’s Option (V4.21)

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Application of Span-Thermal Loading (V4.21)

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Span-Thermal Loading (V4.21)

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Shallow Foundation Modeling (~2016)

• Spread (or Strip) footings

• Options to model overlying structure and/or pile foundation as usual

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Shallow Foundation Modeling (~2016)• Nonlinear Soil-Structure Interaction Analysis

• Numerical integration of vertical stress through a depth

• Resultant internal forces in finite shell elements coupled with soil resistance

• Computation of ultimate bearing resistance and settlement distribution

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Shallow Foundation Modeling (~2016)• Partially implemented in a Beta Version of FB-MultiPier for academic

education purposes

• Hyperbolic constitutive model (Duncan and Chang)

• Nathan Newmark’s stress superposition method, i.e., Stress-Influence Method

Shallow Foundation Modeling Dialog

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Shallow Foundation Modeling (~2016)• Limitation of existing theories

• Need for strain-based method

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FB-MultiPier Update: Part 2 Use of Design Tables and Model Showcase

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Design Tables

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Example Pier for Design Tables

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Pile Axial Forces

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Max D/C in the Piles

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Max D/C in the Columns

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Pier Cap Shear Design Data

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Shear Envelope

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Moment Envelope

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Data Exporting

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Agenda

• Use of Design Tables

• Model Showcase

• Summary

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FB-Multipier ModelsYOU MADE THESE!!!!!

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Any Pile Layout

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Steel H-Piles and Bracing

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“Thin View” Extra Member Bracing

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Barge Fender at Port Canaveral

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Edited General Pier Model

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Multiple Timber Pile Clusters

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Pipe Piles, Strut, Reduced Pier Cap Stiffness

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Cap Thickened and Some Elements Removed

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6 Soil Sets and 4 Pile Types

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4 Pile Types

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Cap Skewed to Pier

X

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Bonner Bridge (H-Pile Pier)

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X and Y Loads at Every Pile Node

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Oxidation Basin

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Oxidation Basin (Plan View)

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General Pier

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“Thin View”

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Two-Span Bridge

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Eleven-Span Bridge (Curved)

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Typical Pier

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V-Pier

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V-pier (Thin View)

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Interesting…Hmmmm

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Cofferdam

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Fender Dummy Piles

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Loading Dummy Piles

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3D Results Window

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Summary

• Design Tables • Conveniently Report Design Forces and Envelopes

• Model Showcase• Endless Possibilities

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Acknowledgements

Bridge engineers (you!)

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Thank you for your time!