Editor's Note

The cornerstones of this journal are its associate editors and our reviewers. It is their work that provides this publication with its final content. The Journal of Bridge Engineering is always eager to hear from anyone—members of the bridge engineering community, members of academia, or practicing engineers—who is interested in serving as an associate editor. Please send your resume, curriculum vitae, qualifications, and areas of bridge engineering expertise to me via ASCE. All applications will be considered. A significant expectation of applicants invited to become associate editors is that they are willing to make the commitment to review and process papers assigned to them in a timely manner. The timely review process of papers is of great significance to the authors who submit their papers to us for review and consideration for publication.

The other cornerstone of the Journal of Bridge Engineering is its reviewers. Their review of the papers determines the quality of the final product published. We would like to hear from anyone in the bridge engineering community, both academicians and practicing engineers—who is interested and believes that he or she is qualified to be a reviewer. Reviewers are generally asked to review only one paper a year, unless they indicate that they can and are willing to review papers more frequently. As a reviewer of papers in a peer-reviewed journal, you would be expected to provide a review in accordance with the guidelines established by ASCE and the profession, normally within 30 days of receipt of the paper. Please send your resume, curriculum vitae, qualifications, and areas of bridge engineering expertise to me via ASCE. All applications will be considered.

One purpose of this journal is to provide its readers with quality papers on current bridge engineering topics and issues. One of the best ways to ensure that we are meeting this need is your input and feedback. Do you believe that there is a need for a special edition or papers on certain topics? Let me know through ASCE so that we can look into these items.

The March 2007 issue of the ASCE Journal of Bridge Engineering begins with a very timely paper. In “Risk-Based Prioritization of Terrorist Threat Mitigation Measures on Bridges,” Ray describes a risk-based methodology developed to facilitate prioritizing terrorist threat mitigation strategies on individual bridges. The methodology and comparison criteria are described, and a simple application example is provided to demonstrate the usefulness of the method.

In “Kinematics of Movable Bridges,” Wallner and Pircher review the simple kinematics of the three traditional movable bridge systems that have been used in the past. However, recently built and proposed movable pedestrian bridges in Europe significantly differ from these traditional systems. The authors believe that understanding the kinematic principles will assist in developing further new ideas in the field of movable bridges.

“Determination of Allowable Differential Settlement in Bridge Approach due to Vehicle Vibrations,” by Zhang and Hu, conducts a theoretical study on determining the allowable differential settlement that can take place between the bridge abutment and the approach embankment. Parametric studies were carried out to learn the types of effects that some parameters, such as the driving direction and speed, have on the allowable differential settlement. The method and procedures to determine the allowable differential settlement are presented by the authors.

The next three papers are in the area of steel bridges. The first—by Connor, Kaufmann, Fisher, and Wright—is titled “Prevention and Mitigation Strategies to Address Recent Brittle Fractures in Steel Bridges.” Brittle-type failures are most critical when there is no evidence of fatigue cracking leading to the fracture and the fracture origin is concealed from view. The authors examine the behavior of two bridge structures in which brittle fractures have developed in recent times, discuss the causes of the failures, and suggest design strategies for prevention, as well as retrofit mitigation techniques.

The second steel bridge–related paper is by Kim, Jung, and White. In “Transverse Stiffener Requirements in Straight and Horizontally Curved Steel I-Girders,” the behavior of one- and two-sided transverse stiffeners in straight and horizontally curved steel I-girders is investigated by using nonlinear finite-element analysis. On the basis of the results of this study as well as other research studies, the authors present new recommendations for the design of transverse stiffeners in straight and horizontally curved steel I-girders.

Finally, Samaan, Kennedy, and Sennah, in “Dynamic Analysis of Curved Continuous Multiple-Box Girder Bridges,” evaluate the natural frequencies and mode shapes of curved multiple-box girder bridges by using finite-element techniques. The finite-element techniques are then substantiated through experimental tests performed on two continuous twin-box girder bridge models of different curvatures. Empirical expressions are determined on the basis of this work.

The next four papers are in the area of concrete bridges. The first, “Use of FEA for Design of a Posttensioning Anchor Head”—by Bastien, Marceau, Fafard, and Ganz—addresses the development process of a multistrand wedge anchor head to be used in posttensioning. The development process traditionally involves a number of different experimental tests, but to answer questions that cannot be answered experimentally, an efficient finite-element model was developed. The paper presents a comparison between the numerical and experimental results and shows the proposed model’s usefulness with regard to the development of new posttensioned anchorages.

Menassa, Mabsout, Tarhini, and Frederick—in “Influence of Skew Angle on Reinforced Concrete Slab Bridges”—describe how the parameters of span length, slab width, and skew angle are used in a finite-element analysis to study the effects of skew angle on simple-span reinforced concrete bridges. The results are compared with reference straight bridges, as well as with American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications and LRFD procedures.

“Detection of Common Defects in Concrete Bridge Decks Using Nondestructive Evaluation Techniques” by Yehia, Abudayyeh, Nabulsi, and Abdelqader studies the different nondestructive evaluation techniques used in assessing concrete bridge deck conditions. Infrared thermography (IR), impact echo (IE), and ground penetrating radar (GPR) are discussed, along with their varying levels of precision. The capabilities of the methods are verified, and comparisons are made among them.

The final concrete-related bridge paper is by Higgins, Lee, Potisuk, and Forrest. “High-Cycle Fatigue of Diagonally Cracked RC Bridge Girders: Laboratory Tests” describes the laboratory tests conducted on full-size girder specimens, with diagonal cracks a common problem present in many girders currently in use in the transportation system. The tests were used to evaluate the possible deterioration in shear capacity under repeated loading. The test results indicated that bond deterioration increased diagonal crack displacements. Analysis methods to predict the shear capacity of diagonally cracked concrete girders subjected to high-cycle fatigue damage are provided.

The 11th and 12th papers in this issue of the Journal of Bridge Engineering are in the area of composites, and both are written by Zou and Huckelbridge. In “Simulation of Crack Growth in FRP Reinforced Concrete,” work based on a finite element and fatigue model was used to study crack development and stabilization.

“Experimental Analysis of Crack Growth in GFRP Reinforced Concrete” describes experiments that were conducted to investigate the bond performance of GFRP-reinforced concrete under constant amplitude cyclic fatigue loading. The crack growth was monitored, and the effects of moderate overloads were also investigated.

The final two papers in this issue are on the subject of long span bridges. In “Application of Suspension Bridges Stiffened by Prestressed Concrete Slabs in China”—by Hsu, Shu, and Yang—the authors describe the work performed to stiffen four suspension bridges by using prestressed concrete slabs.

Finally, Ren, Lin, and Peng—in “Field Load Tests and Numerical Analysis of Qingzhou Cable-Stayed Bridge”—discuss the results of field static-load tests and numerical analysis of the Qingzhou cable-stayed bridge over the Ming River in China. In addition to the field tests, a finite-element model was also created, calibrated, and compared with the field results. The results of the work showed that the initial equilibrium configuration of the bridge plays an important role in the finite-element calculations. Both the analytical and experimental results found that the bridge is in an elastic state. The calibrated finite-element model will also be used to evaluate the as-built condition of the bridge as well as serving as a baseline for future structural health monitoring.