Papers in This Issue

The July 2007 issue of the Journal of Bridge Engineering begins with a paper on vibration of stay cables. In “Vibration Control of Stay Cables of Shandong Binzhou Yellow River Highway Bridge Using Magnetorheological Fluid Dampers,” Li, Liu, Li, Guan, and Ou describe the use of an innovative control algorithm for active and semiactive control of mass-distributed dynamic systems. The longest cables of the Shandong Binzhou Yellow River Highway Bridge were stabilized to suppress vibration using 40 magnetorheological fluid dampers. Field tests were carried out and determined that the semiactive magnetorheological dampers can provide greater supplemental damping than “passive-on” or “passive-off” dampers.

Next are three papers on bridge desks. In the first one by Oh, Lew, and Choi, the issue of safety of deck slabs and the resulting frequent repair and strengthening is investigated. In “Realistic Assessment for Safety and Service Life of Reinforced Concrete Decks in Girder Bridges,” the development of a realistic assessment system that can estimate the safety and remaining service life of concrete bridge decks is presented. By determining a realistic and accurate assessment of the bridge deck, the cost of repairs can be eliminated and the loss of use to the public during possibly unnecessary repairs can be prevented. The proposed method uses an assessment of corrosion along with analysis of flexture, shear, and fatigue.

The second bridge deck paper is titled “Low-Cycle Fatigue Testing of High-Performance Concrete Bonded Overlay-Bridge Deck Slab Systems” and is authored by Issa, Alhassan, and Shabila. This paper describes a field performance evaluation of a full-scale prototype bridge deck using plain and fibrous latex–modified concrete and microsilica concrete overlays. The study found that this overlay provided good results.

“Stiffness and Strength of Metal Bridge Deck Forms,” by Egilmez, Helwig, Jetann, and Lowery, is the final paper on bridge decks. This paper presents the results of the first phase of research investigating the bracing behavior of metal bridge deck forms. While the bracing effects of these forms are used in building construction, due to connection details, the bracing effects are normally not considered when these forms are used in bridge construction. Shear diaphragm tests were conducted to determine the shear stiffness and strength of the forms. The experimental results on the diaphragms indicate the potential for the bracing of steel bridge girders using metal deck forms.

The fifth paper in this issue of the Journal of Bridge Engineering is about bridge expansion joints. Malla, Shaw, Shrestha, and Brijmohan in “Development and Laboratory Analysis of Silicone Foam Sealant for Bridge Expansion Joints,” present the results of the development of an elastomeric foam-type joint sealant for use in small-movement bridge expansion joints. The paper presents the results of an investigation using both foam and solid sealants.

“Deck-Mounted Steel Post Barrier System,” by Reid, Faller, and Hascall, presents the results of an evaluation of an existing mountable safety barrier system on a fiber-reinforced plastic bridge deck. This existing barrier was previously crash tested successfully on a wood bridge deck. Rather than performing a full-scale crash test, the components of the existing system were evaluated using worst-case conditions on dynamic bogie crash tests along with nonlinear finite element analysis computer simulations. Both the testing and simulations indicated that the barrier would function satisfactorily. In addition, these studies provided information on how this barrier would function on other types of bridge decks.

The next four papers address issues pertaining to steel bridges. Barth, Yang, and Righman, in “Simplified Moment Redistribution of Hybrid HPS 485W Bridge Girders in Negative Bending,” present the results of a study in simplified moment redistribution procedures. The AASHTO LRFD Bridge Design Specifications (AASHTO 2004) currently permit moment redistribution procedures for homogeneous girders. This study investigated whether these procedures could be used for hybrid HPS 485W girders. The work concluded that they could be used, and a design example application of the procedures yielded a 13% lighter negative bending section.

The second steel bridge paper is by Bell and Linzell. “Erection Procedure Effects on Deformations and Stresses in a Large-Radius, Horizontally Curved, I-Girder Bridge” presents the results of an investigation of a horizontally curved, six-span steel I-girder bridge that experienced severe geometric misalignments and fit-up problems during erection. Using information from this bridge, a numerical model was created to study the effects of erection sequencing, upper lateral bracing erection, and the use of temporary supports.

“Live-Load Analysis of a Curved I-Girder Bridge,” by Barr, Yanadori, Halling, and Womack, presents the results of a study on a three-span, curved steel I-girder bridge that was tested under three boundary condition states to determine its response to live load. Measure live-load strains were used to calibrate a finite element analysis; these results were compared with results obtained using the V-Load Method. It was determined that while the V-Load Method yielded positive bending moments which were close to those predicted by the finite element model for some girders, this result was due to the V-Load Method being unconservative and the distribution factor being conservative.

The final steel bridge paper is also on the subject of curved girders. Howell and Earls, in “Curved Steel I-Girder Bridge Response during Construction Loading: Effects of Web Plumbness,” investigate the effects of web out-of-plumbness on the structural performance of curved steel I-girder bridges. The authors note that current construction practice is to take measures to minimize out-of-plumbness, as performance of structures with this problem are poorly understood. The paper describes research which uses nonlinear finite element modeling to study the various effects that web out-of-plumbness has on flange tip stresses, vertical and lateral deflections, cross–sectional distortion, and cross frame demands.

“Unified Approach for Analysis of Box-Section Members under Combined Actions,” by Huang and Liu, presents the resultsof a theoretical study of a unified failure expression for reinforced box section members under combined bending, shear, axial force, and torsion. The results of the theoretical analysis were compared with experimental results, and good correlation was found.

The twelfth paper in this issue of the Journal is by Mackie and Stojadinović. “R-Factor Parameterized Bridge Damage Fragility Curves” describes a method of computing damage fragilities for three damage states (concrete cover spalling, longitudinal bar buckling, and column failure) using bridge reduction factors (R-factors).

“Experimental Investigation of Shear Capacity of Precast Reinforced Concrete Box Culverts” presents the results of a study to investigate the shear capacity of precast reinforced concrete box culverts. While one might not think of a box culvert as a bridge structure, they are nevertheless part of the structure inventory of state DOTs and are maintained by their bridge personnel. Garg, Abolmaali, and Fernandez present the results of an experimental program which investigated the shear capacity of precast reinforced concrete box culverts.

The final paper in this issue of the journal is “Estimation of Collapse Load of Single-Cell Concrete Box-Girder Bridges,” by Kurian and Menon. Collapse loads for single-cell concrete box girder bridges with simply supported ends are based on either space truss analogies or collapse mechanisms. Experimental studies have revealed that the formulations based on collapse mechanisms are more versatile and better–suited to box sections. However, when there is cross-sectional distortion, significant errors occur. The paper proposes a modification to the existing theory to correct this problem. Experiments were conducted and it was determined that the modified theory predicted results that were close to the experimental results.

Finally, there is a technical note by Kumar and Paul. “Force-Deformation Behavior of Isolation Bearings” presents new relations to calculate yield force, horizontal displacement, and damping for isolation bearings.