Journal of Bridge Engineering

Reliability Based Dynamic Amplification Factor on Stress Ranges for Fatigue Design of Existing Bridges

Wei Zhang and C. S. Cai
A dynamic amplification factor (DAF) or dynamic load allowance (IM) is typically used in bridge design specifications to include dynamic effects from vehicles on bridges. The calculated live load stress ranges might not be correct due to varied dynamic amplification effects in different regions alon ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000387] posted Sat Feb 11, 2012.

Measurement System Configuration for Damage Identification of Continuously Monitored Structures

Irwanda Laory, Nizar Bel Hadj Ali, Thanh N. Trinh, and Ian F. C. Smith
Measurement system configuration is an important task in structural health monitoring in that decisions influence the performance of monitoring systems. This task is generally performed using only engineering judgment and experience. Such approach may result in either a large amount of redundant dat ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000386] posted Sat Feb 11, 2012.

Instrumentation and Modeling of I35W St. Anthony Falls Bridge

Brock D. Hedegaard, Catherine E. W. French, Carol K. Shield, Henryk K. Stolarski, and Ben J. Jilk
The I-35W St. Anthony Falls Bridge was constructed to replace the steel truss bridge that collapsed on August 1, 2007. The design of the replacement bridge featured a smart bridge system. The smart bridge concept included instrumentation for long-term monitoring of the structural behavior of the bri ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000384] posted Thu Feb 9, 2012.

Evaluating Codes Criteria for Regular Seismic Behavior of Continuous Concrete Box Girder Bridges with Unequal Height Piers

J. E. B. Guirguis and S. S. F. Mehanny
The seismic design and response prediction of irregular bridges supported on piers of unequal heights - a commonly adopted solution when crossing steep-sided valleys - represent a particularly challenging problem that is yet not effectively addressed by seismic design code provisions worldwide. From ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000383] posted Fri Feb 3, 2012.

Development of State-Specific Load and Resistance Factor Rating Method

Michel Ghosn, Bala Sivakumar, and Feng Miao
Recognizing the limitations of the generic truck weight data and conservative assumptions made during the calibration of live load factors for bridge rating, the AASHTO Load and Resistance Factor Rating (LRFR) Manual for Bridge Evaluation (MBE) provides sufficient flexibility and allows state agenci ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000382] posted Wed Feb 1, 2012.

Development of an Efficient Maintenance Strategy for Corroded Steel Bridge Infrastructures

J. M. R. S. Appuhamy, M. Ohga, T. Kaita, P. Chun, and P. B. R. Dissanayake
The potential for the structural capability degrading effects due to corrosion is of profound importance and must be both fully understood and reflected in bridge inspection and maintenance programmes. As the number of steel bridge infrastructures increase throughout the world, it is an exigent task ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000381] posted Wed Feb 1, 2012.

Cyclic Behavior of FRP-Concrete Bridge Pier Frames

Bin Li, Pedram Zohrevand, and Amir Mirmiran
Concrete-filled fiber reinforced polymer (FRP) tubes (CFFT) were initially developed without any internal steel reinforcement as viable alternatives to conventional reinforced concrete (RC) columns in non-seismic regions. Studies have since shown that extending CFFT application to seismic regions re ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000380] posted Tue Jan 31, 2012.

A Field Test of Magnetic Methods for Corrosion Detection in Prestressing Strands in Adjacent Box-Beam Bridges

Bertrand Fernandes, Michael Titus, Douglas Karl Nims, Al Ghorbanpoor, and Vijay Devabhaktuni
Magnetic methods are progressing in the detection of corrosion in prestressing strands in adjacent precast, prestressed concrete box-beam bridges. This study is the first field trial of magnetic strand defect detection systems on an adjacent box-beam bridge. A bridge in Fayette County, Ohio, which w ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000379] posted Tue Jan 31, 2012.

Longitudinal Joints with Accelerated Construction Features in Decked Bulb-Tee Girder Bridges: Strut-and-Tie Model and Design Guidelines

Zhi-Qi He, Zhongguo John Ma, Cheryl E. Chapman, and Zhao Liu
This paper focuses on the development of a strut-and-tie model that can be used in the design of previously developed longitudinal joints with accelerated construction features. Four joint specimens reinforced with tight bend diameter U-bars and previously tested under bending are summarized here to ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000378] posted Tue Jan 31, 2012.

Bending Strength of Horizontally Curved Composite I-Girder Bridge

Chai H. Yoo, Kyungsik Kim, Kyoung C. Lee, and Junsuk Kang
Horizontally curved I-girders are subjected to combined vertical bending and torsion under gravity loads alone. The torsional behavior of open I-shaped girders is commonly and conveniently transformed to self-equilibrating lateral bending of flanges. The interaction of vertical bending and lateral f ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000377] posted Thu Jan 26, 2012.

A Probability of Collapse Expression for Bridges Subject to Barge Collision

Michael T. Davidson, Gary R. Consolazio, Daniel J. Getter, and Falak D. Shah
Accounting for waterway vessel collision is required in the structural design of bridges spanning navigable waterways. During collision events, massive waterway vessel groups such as barge flotillas are capable of dynamically transmitting horizontal forces to impacted bridge components. Furthermore, ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000376] posted Fri Jan 20, 2012.

Stress-Laminated-Timber Decks Subjected to Eccentric Loads in the Ultimate-Limit State

K. Ekholm, R. Crocetti, and R. Kliger
Stress-laminated-timber (SLT) bridge decks are generally designed using either linear hand calculation methods or linear finite element models. Several studies have shown, however, that the behaviour of SLT decks is non-linear when loaded until failure. In this paper, several linear design methods a ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000375] posted Fri Jan 20, 2012.

Total Cost-Benefit Analysis of Alternative Corrosion Management Strategies for a Steel Roadway Bridge

Scott Walbridge, Dilum Fernando, and Bryan T. Adey
This paper describes a methodology for evaluating alternative corrosion management strategies for a steel roadway bridge based on a total cost-benefit analysis. In this analysis, the impacts of girder type and preservation intervention selection on the bridge owner, users, and public are considered. ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000374] posted Fri Jan 20, 2012.

Damage Evaluation for Concrete Bridge Deck by Means of Stress Wave Techniques

Tomoki Shiotani, Hiroyasu Ohtsu, Shohei Momoki, Hwa Kian Chai, Hiroshi Onishi et al.
Different from post failure maintenance in many perspectives, preventive maintenance of civil engineering structures is another highly crucial measure not only for achieving efficient distribution of limited budget over existent ageing infra-structures, but also for maximizing their service life spa ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000373] posted Fri Jan 20, 2012.

Effect of Temperature on Daily Modal Variability of a Steel-Concrete Composite Bridge

Amir A. Mosavi, Rudolf Seracino, and Sami Rizkalla
Vibration-based damage detection techniques typically use changes of modal characteristics of bridges as a possible indication of damage. However, structural damages are not the only cause of these changes. This study investigates the effect of temperature variations on modal characteristics of a tw ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000372] posted Fri Jan 20, 2012.

Probabilistic Modeling of Bridge Deck Unseating during Hurricane Events

Navid Ataei and Jamie E. Padgett
Although coastal bridges have exhibited significant susceptibility to damage during hurricane induced wave and surge events, probabilistic models are lacking to quantify the vulnerability of bridges under a range of structural or hazard parameters and support hurricane risk assessment and mitigation ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000371] posted Thu Jan 12, 2012.

Reliability-Based Calibration of Load Factors for LRF Design of Reinforced Concrete Bridges under Multiple Extreme Events: Scour and Earthquake

Azadeh Alipour, Behrouz Shafei, and Masanobu Shinozuka
A multi-hazard reliability-based framework is developed through this study to evaluate the structural response of reinforced concrete bridges under the combined effects of pier scour and earthquake events. This framework is utilized to calibrate the scour load modification factors for design of brid ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000369] posted Fri Jan 6, 2012.

Using Weigh-In-Motion Data to Determine Aggressiveness of Traffic for Bridge Loading

Eugene J. OBrien and Bernard Enright
This paper presents results based on the analysis of an extensive database of weigh-in-motion (WIM) data collected at five European highway sites in recent years. The data are used as the basis for a Monte Carlo simulation of bridge loading by two lane traffic, both bidirectional and same-direction. ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000368] posted Fri Jan 6, 2012.

Experimental Study on Fatigue Strength of Corroded Bridge Wires

Shunichi Nakamura and Keita Suzumura
Fatigue tests were conducted for corroded galvanized steel wires on three corrosion levels, showing that fatigue strength of corroded wires lowers as corrosion progresses. Corrosion pits were measured on the corroded specimens, showing severer corrosion produced deeper pits in more condensed areas. ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000366] posted Thu Jan 5, 2012.

Automated Ice Inference and Monitoring on the Veterans' Glass City Skyway Bridge

J. Kumpf, A. Helmicki, D. K. Nims, V. Hunt, and S. Agrawal
Under certain weather conditions, the Veterans' Glass City Skyway (VGCS) Bridge in Toledo, OH accumulates ice on the stay sheaths in such a way that has led to large fragments falling into traffic lanes. In order to aid the Ohio Department of Transportation (ODOT) in their response to this, an autom ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000365] posted Thu Jan 5, 2012.

Cable-Stayed Bridges: A Case Study for Ambient Vibration-Based Cable Tension Estimation

S. Kangas, A. Helmicki, V. Hunt, R. Sexton, and J. Swanson
A cable-stayed bridge recently constructed by the Ohio Department of Transportation incorporates measures put forth by a Federal Highway Administration study to mitigate stay motion. In following recent trends, the stays at this bridge are built without the use of grout for the purposes of inspectio ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000364] posted Thu Jan 5, 2012.

Development Length Tests of Full-Scale Prestressed Self-Consolidating Concrete Box and I-Girders

Bassem Andrawes, Andrew Pozolo, and Zhe Chen
Self-Consolidating Concrete (SCC) is a highly workable concrete with tremendous potential to reduce the production time and cost of precast members. Institutions in Japan, Europe, and the United States have successfully utilized SCC in large-scale applications, particularly in bridges. However, lack ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000363] posted Fri Dec 23, 2011.

A Vibration Based Method and Sensor for Monitoring of Bridge Scour

Ali Zarafshan, Amirhossein Iranmanesh, and Farhad Ansari
Scour is the major cause for many bridge failures and damage to piers and abutments. Scour is not easily discernible since it is hidden under the channel flow. Over the years, a number of sensors have been developed for detection of scour depth. Development, testing and field implementation of a new ... [Journal of Bridge Engineering doi:10.1061/(ASCE)BE.1943-5592.0000362] posted Fri Dec 23, 2011.

LRFD Resistance Factors for Design of Driven H-Piles in Layered Soils

Sherif S. AbdelSalam, Sri Sritharan, and Muhannad T. Suleiman
The load and resistance factor design (LRFD) of piles embedded in layered soils that are commonly classified as sand, clay, and mixed soil sites is investigated using static analysis methods at the strength limit state. Unlike the current practice, the main emphasis of this study is to use a more cl ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000253] published Fri Dec 16, 2011.

Perspectives on AASHTO Load and Resistance Factor Design

Daniel H. Tobias
The American Association of State Highway and Transportation Officials (AASHTO) first published the Load and Resistance Factor Design Bridge Design Specifications (LRFD Code) in 1994 after several years of development. Each year since its inception, the reliability-based LRFD Code has been refined ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000286] published Fri Dec 16, 2011.

Calibration of Live-Load Factor in LRFD Bridge Design Specifications Based on State-Specific Traffic Environments

Oh-Sung Kwon, Eungsoo Kim, and Sarah Orton
In this paper, the live load factor in the Strength I Limit State in the AASHTO LRFD Bridge Design Specifications is calibrated based on state-specific traffic environments and bridge configurations. As the initial development of the live load factor in the LRFD specifications was intended to be app ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000209] published Fri Dec 16, 2011.

Full-Scale Testing of Pretensioned High-Strength Concrete Girders with Debonded Strands

Jae-Ki Kim, Hyun-Oh Shin, Hyun-Yang Shin, and Young-Soo Yoon
The flexural and shear behavior of three full-scale pretensioned high-strength concrete (HSC) bridge girders, which were designed to a modified bulb tee (BT) section according to AASHTO specifications, were investigated experimentally to evaluate the applicability of high-strength concrete and a hig ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000251] published Fri Dec 16, 2011.

Evaluation of Combination Rules for Orthogonal Seismic Demands in Nonlinear Time History Analysis of Bridges

Vahid Bisadi and Monique Head
One of the parameters that directly affects the seismic demand on a bridge is the excitation angle of the ground motion. Since analyzing a bridge with all possible excitation angles is impractical, combination rules have been used for computation of seismic demands. Provisions and specifications rec ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000241] published Fri Dec 16, 2011.

Performance Evaluation of Empirically and Traditionally Designed Bridge Decks

Samir N. Shoukry, Gergis W. William, Kevyn C. Mcbride, Mourad Y. Riad, and Jimmy D. Wriston
The focus of this study is to assess the performance of empirically designed reinforced concrete bridge decks versus those designed using traditional analytical design methods and to check the adequacy of both design methods by correlating the theoretical results with field observations. A case stud ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000245] published Fri Dec 16, 2011.

Conference Papers and Prior Publication

Chris Hendrickson, Sue McNeil, Gang-Len Chang, and Anil Agrawal
Abstract not available. [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000294] published Fri Dec 16, 2011.

Special Issue on AASHTO-LRFD Bridge Design and Guide Specifications: Recent, Ongoing, and Future Refinements

Daniel H. Tobias
Abstract not available. [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000297] published Fri Dec 16, 2011.

Bridge Rating Using System Reliability Assessment. II: Improvements to Bridge Rating Practices

Naiyu Wang, Bruce R. Ellingwood, and Abdul-Hamid Zureick
The current bridge-rating process described in AASHTO Manual for Bridge Evaluation, First Edition permits ratings to be determined by allowable stress, load factor, or load and resistance factor methods. These three rating methods may lead to different rated capacities and posting limits for the sam ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000171] published Fri Dec 16, 2011.

Performance of Bridge Columns Subjected to Blast Loads. I: Experimental Program

Eric B. Williamson, Oguzhan Bayrak, Carrie Davis, and G. Daniel Williams
Statistical data from past terrorist attacks show that transportation infrastructure has been widely targeted, and a significant percentage of the attacks against transportation structures have been directed towards bridges. Recent threats to bridges in the United States validate this concern and ha ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000220] published Fri Dec 16, 2011.

Reliability-Based Dynamic Load Allowance for Capacity Rating of Prestressed Concrete Girder Bridges

Lu Deng, C. S. Cai, and Michele Barbato
The current highway bridge design in the United States follows the AASHTO-LRFD specifications, which prescribe a dynamic load allowance, IM, of 0.33 for the dynamic effect of truck/tandem loading. Studies have shown that the IM value prescribed by the LRFD code may underestimate this dynamic effect ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000178] published Fri Dec 16, 2011.

Investigation of Bursting Forces in Anchorage Zones: Compression-Dispersion Models and Unified Design Equation

Zhi-Qi He and Zhao Liu
Anchorage zones of posttensioned structures are prone to splitting cracks, necessitating rational reinforcement design methods for anticracking in such regions. This paper presents a generalized method to calculate bursting forces in posttensioned anchorage zones. Compression-dispersion models are i ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000187] published Fri Dec 16, 2011.

Papers in This Issue

Anil K. Agrawal
Abstract not available. [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000292] published Fri Dec 16, 2011.

Introduction to PILOT Database and Establishment of LRFD Resistance Factors for the Construction Control of Driven Steel H-Piles

Matthew J. Roling, Sri Sritharan, and Muhannad T. Suleiman
The recently established and publicly available database for Pile-Load Tests (PILOT) is an amalgamated, electronic source of rich information comprising both static and dynamic data for driven piles (http://srg.cce.iastate.edu/lrfd/database%20downloads.html). The database, which includes quality-ass ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000247] published Fri Dec 16, 2011.

Proposed Modification of AASHTO-LRFD for Computing Stress in Unbonded Tendons at Ultimate

M. H. Harajli
In 1998, AASHTO-LRFD adopted a new equation for evaluating the stress f in unbonded tendons at ultimate. In explaining the development and applicability of the new AASHTO-LRFD equation, some investigators concluded that the new equation is conservative and more rational when compared with the ACI bu ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000183] published Fri Dec 16, 2011.

Equivalent Static Analysis Method for Barge Impact-Resistant Bridge Design

Daniel J. Getter, Gary R. Consolazio, and Michael T. Davidson
In the United States, barge impact-resistant bridge design typically involves static application of code-prescribed impact loads. However, the existing static analysis procedure neglects crucial dynamic effects in the impacted bridge. Recent experimental and analytical studies have uncovered importa ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000224] published Fri Dec 16, 2011.

Bridge Rating Using System Reliability Assessment. I: Assessment and Verification by Load Testing

Naiyu Wang, Curtis O'Malley, Bruce R. Ellingwood, and Abdul-Hamid Zureick
Condition assessment and safety verification of existing bridges and decisions as to whether a bridge requires posting currently are addressed through analysis, load testing, or a combination of these methods. The rating process is described in AASHTO's Manual for Bridge Evaluation, which permits ra ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000172] published Fri Dec 16, 2011.

Proposed Revisions to AASHTO-LRFD Bridge Design Specifications for Orthotropic Steel Deck Bridges

Brian M. Kozy, Robert J. Connor, Duncan Paterson, and Dennis R. Mertz
The orthotropic steel deck bridge is a structural system that has the potential to provide an extended service life and standardized modular design as compared to more conventional bridge construction. This paper summarizes proposed changes to the fifth edition of the AASHTO LRFD Bridge Design Speci ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000214] published Fri Dec 16, 2011.

Reviewers

Abstract not available. [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000293] published Fri Dec 16, 2011.

Investigation of AASHTO Live-Load Reduction in Reinforced Concrete Slab Bridges

F. El Meski, M. Mabsout, and K. Tarhini
This paper presents the results of a three-dimensional (3D) finite-element study that investigated the effect of the multipresence factor of the load-reduction factors used in the AASHTO Bridge Design Specifications. Typical one-span, two-equal-span continuous, simply supported, three- and four-lane ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000237] published Fri Dec 16, 2011.

Performance-Based Design of Drilled Shaft Bridge Foundations

Lance A. Roberts, Damon Fick, and Anil Misra
The design of deep foundations for bridge structures should ideally consider the interaction between the soil and the foundation element to properly model the side and tip resistance components. A soil-structure interaction model, such as the t-z model method, can be utilized to develop a load-displ ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000222] published Fri Dec 16, 2011.

Evaluation of AASHTO-LRFD Design Methods for Thermal Loads in Fixed-Flexible Twin-Walled R/C Bridge Piers

Arturo E. Schultz, Christopher J. Scheevel, and Krista M. Morris
The design of reinforced concrete fixed-flexible twin-walled bridge piers for lateral loads is an ambiguously defined task for bridge engineers. As the bridge experiences lateral loads, primarily from temperature fluctuations and time-dependent effects, the walls undergo cracking, requiring designer ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000240] published Fri Dec 16, 2011.

Revisit of AASHTO Effective Flange-Width Provisions for Box Girders

Zhibin Lin and Jian Zhao
The nonuniform normal stress distribution along the flange of thin-walled flexural members, such as box girders, is recognized as shear lag effects. Effective flange width is widely used to consider shear lag effects in bridge design. The existing provisions for effective flange width in AASHTO LRFD ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000194] published Fri Dec 16, 2011.

Evaluation of FRP Posttensioned Slab Bridge Strips Using AASHTO-LRFD Bridge Design Specifications

Martin Noel and Khaled Soudki
Deterioration of concrete structures caused by corrosion of steel reinforcement requires large capital investments in order to repair or replace existing structures which may or may not be nearing the end of their expected service lives. Fiber-reinforced polymer (FRP) reinforcement has emerged as a ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000226] published Fri Dec 16, 2011.

Unified Approach for LRFD Live Load Moments in Bridge Decks

Christopher Higgins, O. Tugrul Turan, Robert J. Connor, and Judy Liu
Current AASHTO-LRFD specifications use many disparate design provisions to establish live load demands in bridge decks. As an example, approximately 17% of Chapter 4 addresses the analysis of decks. One of the AASHTO-LRFD analysis methods for decks uses an orthotropic plate model. The present AASHTO ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000217] published Fri Dec 16, 2011.

Performance of Bridge Columns Subjected to Blast Loads. II: Results and Recommendations

Eric B. Williamson, Oguzhan Bayrak, Carrie Davis, and G. Daniel Williams
Guidelines for the design of critical bridge components subjected to blast loads are currently not available to the general bridge engineering community. Historically, however, transportation assets have proven to be attractive targets for terrorists because of their open access, utilization by larg ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000221] published Fri Dec 16, 2011.

Framework for Simplified Live Load Distribution-Factor Computations

Jay A. Puckett, Sharon X. Huo, Mark Jablin, and Dennis R. Mertz
The live load distribution-factor (LLDF) equations in the AASHTO-LRFD specifications were developed under National Cooperative Highway Research Program (NCHRP) Project 12-26. These equations include limited ranges of applicability, and when these ranges are exceeded, a refined analysis must be used. ... [J. Bridge Eng. doi:10.1061/(ASCE)BE.1943-5592.0000285] published Fri Dec 16, 2011.