The objective of this special issue on bridge structures is to increase the body of knowledge on engineering, construction, and management in relation to bridges. Specifically, it aims at bringing up to date the latest bridge research findings, technical information, and practice on planning, design, construction, maintenance, replacement, management, security, and safety of highway and railroad bridges. The call for papers addressed topics on field monitoring and testing methods, innovative methods for infrastructure construction, high-performance and high-strength materials, bridge design and construction, rating of existing structures, load and resistance factor design, bridge serviceability issues, bridge management systems, aesthetics considerations, and design codes, specifications, and standards.

In response to the call for submissions, 13 papers were received, out of which one paper was later withdrawn. From the remaining 12 papers, 4 papers were rejected and 8 papers were accepted. The papers included in the special issue are on various topics, such as field testing and finite element modeling of a bridge, life-cycle management system, optimization of posttensioned bridges, barrier-overhang connection to bridge decks, FRP link slabs in jointless bridges, pounding effects in bridges with consideration of spatial variability of the ground motion, hysteresis damping effect of cross-ties on cables vibration of cable-stayed bridges, and pile group protection with riprap mattress. Additional details and information on the published papers are provided below.

The paper written by A. N. Daumueller and D. V. Jáuregu is on strain-based evaluation of a steel railroad bridge. It discusses the development of four finite-element models that were developed to study the sensitivity of a bridge in New Mexico to floor-system connection fixity and the ballast. Accuracy of the computer models was verified through a diagnostic load test based on strain measurement.

Life-cycle management strategy for steel girder bridges is investigated by K. K. L. So et al. This article proposes an integrated life-cycle management strategy on steel girders in bridges in which corrosion deterioration and fatigue damage prediction models are mapped with girders’ performance conditions. A practical example to demonstrate the applicability of the proposed strategy is also illustrated.

The paper written by B. Chang et al. addresses cost optimization of posttensioned concrete box girder bridges following the AASHTO LRFD specifications. Design charts were developed with consideration of different span length, section depth, web spacing, tendon profile, and concrete strength. It was observed that high strength concrete enables the achievement of significantly longer span lengths and larger web spacing that is not achievable when using normal strength concrete.

The same authors of the previous paper are also involved in the next one, which is on the structural behavior and design of barrier-overhang connection in concrete bridge superstructures. This investigation addresses the AASHTO’s LRFD and standard design methodologies of concrete deck slab, deck overhang, and barrier and combined barrier-bridge overhang. The failure mechanism, design philosophy, and load cases including extreme event limit states for barrier and overhang are discussed.

The paper by A. Saber and A. R. Aleti is on the behavior of fiberglass-reinforced plastic (FRP) link slabs in jointless bridge decks. The study includes numerical analyses and the experimental work to investigate the behavior of the FRP link slab and confirm its feasibility. The results showed that the technique would allow simultaneous achievement of structural need, lower flexural stiffness of the link slab approaching the behavior of a hinge, and sustainability need of the link slab.

A case study on the pounding effects in bridges with consideration of spatial variability of the ground motion is conducted by G. Tecchio et al. The study includes a parametrical analysis of the seismic response of simple span bridges to asynchronous earthquake ground motion. The analysis considers a series of nonlinear time history analyses, in which the variation of the frequency content in the accelerograms at the pier bases was described by considering the power spectral density function and the coherency function.

P. G. Papadopoulos et al. investigate the hysteresis damping effect of cross-ties on cables vibration of cable-stayed bridges. A short computer program is presented, for the step-by-step dynamic analysis of isolated cables or couples of parallel cables of a cable-stayed bridge, connected to each other and possibly with the deck of the bridge, by very thin pretensioned cross-ties and subjected to various axial forces.

The paper on pile group protection with riprap mattress is written by C. Chreties et al. It contains new experimental data on plan dimensions for riprap mattresses used in pile group protection against edge failure are analyzed. The influence of flow conditions and the distance between piles in plan dimensions of riprap mattresses are addressed, and an alternative methodology for the experimental study of edge failure in pile groups is proposed and verified.

Peer reviewers are key to advancing quality of scholarly journals. As such, the guest editors of the special issue would like to extend special thanks to the many volunteer reviewers who carefully read each of the articles submitted for publication. Their observations and comments have been a great help to both the authors to improve their papers and to the guest editors to make objective decisions with regard to the quality of the submissions.

Finally, we would like to acknowledge the contribution of all authors and hope that the readers find this issue informative and beneficial.

Sami W. Tabsh
Husam Najm