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Highway bridges exposed to intentional or unintentional fire followed by combined vehicle impact and air blast are at risk of significant damage and, possibly, collapse. Limited studies examining the complex effects of these extreme demands on bridge support elements and parametrizing their response and damage are found in the open literature. Research that is presented is part of an ongoing numerical investigation examining round, multi-column, reinforced concrete (RC), bridge pier behavior subject to multi-hazard scenarios involving fire, vehicle impact, and air blast. Detailed nonlinear finite element analysis models of single columns and multi-column piers supported by a pile foundation system were created using LS-DYNA. A unique multi-step modeling approach was developed to simulate their post fire vehicular impact and blast response and performance was assessed based on defined damage levels. Parametric studies were conducted to evaluate the effects of various multi-hazard scenarios and on different multi-column pier configurations. The studies first examined pier behaviors under vehicle impact and blast and then looked at the combined effects of fire followed by vehicle impact and blast on pier performance and robustness. The effectiveness with which select in-situ retrofit schemes mitigated damage was also investigated using the models by examining final failure modes. Model development steps will be summarized along with results from analyses from ongoing parametric and retrofit studies.

Bridges are one of the most expensive and vital infrastructures in the transportation system. However, the bridge substructure such as piers, undergoes various kinds of deterioration and damages overtime. Different kinds of repair and rehabilitation practices are needed to protect bridges from future damages. One of such common methods of pier protection is pier encasement. Pier encasement involves enclosing an existing pier with suitable materials such as PVC pipe, to increase its strength. However, the process of pier encasement increases the overall width of the pier, which might result in the rise of headwater elevation at the bridge vicinity. Moreover, this rise in headwater elevation may cause serious problems in areas located in high-risk flood zones. When the bridge and its piers are located within the defined floodway boundaries of a Federal Emergency Management Administration (FEMA) National Flood Insurance Program (NFIP) Zone AE, no rise in water surface elevation must be maintained. Therefore, this study was undertaken to find the effects of pier encasement on headwater elevation under varying pier and channel configurations. In order to study the impact of pier encasement, HEC-RAS, was used for hydraulic simulation. The hydraulic simulation was carried out for various channel configurations. The comparison was done for encased and non-encased pier conditions for the varying conditions of channel configurations, such as channel width, slope, and flow volume. The study showed the rise in headwater elevation for the channel with a smaller bottom width (20 ft, 40 ft, 60 ft, and 80 ft). The rise in headwater elevation was further increased for steeper slopes (0.7% and 1.0%) and for higher flow volume.Furthermore, winter ice jam around a bridge structure can cause serious damage to the bridge and has been one of the major problems with bridges in the northern belt of the USA. The bridge piers, which comes in contact with ice, has a significant impact on ice jam. Moreover, a bridge pier enforces substantial changes in river flow dynamics, especially in ice jam conditions. Therefore, the effect of pier encasement on water surface elevation during the winter period (ice jam) was also analyzed using HEC-RAS. After running numerous models with various channel configurations, it was found that the pier encasement effect was minimal in head water elevation even for the ice jammed bridges. Nevertheless, the minor rise was noticed for smaller channel bottom widths (20 ft and 40 ft) only with steeper slope (0.7% and 1.0%).Since these findings were derived using various hypothetical channel configurations, the further application of this study was pursued in various existing bridges in the Grand River, OH, to verify that the concept derived from the generic channel section is valid in real word applications. The pier encasement was done for bridges located on the Grand River. The hydraulic simulation was conducted for computing water surface elevation for both encased and non-encased bridge structures. The result was found to be consistent with the parametric study performed for generic channel sections. After encasement, the wider channel showed no rise in water surface elevation, however, the channel with smaller bottom width showed a slight rise in water surface elevation (0.03 ft).

The present research investigates the response of load bearing reinforced concrete structural members, and proposes design of deployable honeycomb energy absorber to shield and protect the structures against extreme loading events such as impact and blast loadings. Application of CFRP-composite sheets and honeycomb cellular structure were studied to reduce the damages to the structural members caused by impact loading. This study involves development of three-dimensional complex nonlinear finite element analysis models of as-built and CFRP-strengthened reinforced concrete structural members such as solid slab and slab with openings, beam, single hammerhead bridge pier column, and honeycomb cellular structure using ANSYS and LS-DYNA software programs at the Ohio Supercomputer Center. Finite element results of the proposed models indicated that: 1. Slabs with multiple rectangular and elliptical shape openings with aspect ratio greater than one outperformed the slabs with circular, square, and diamond shape single opening in terms of floor stiffness, and ultimate flexural strength capacity.2. Peak dynamic impact force of the pier surpassed the AASHTO impact design force. CFRP-wraps applied to the pier helped to contain incurred localized damage and to redistribute the effect of vehicular impact load.3. U-shaped and complete wrap strengthening were effective in improving the response of reinforced concrete beams under drop hammerhead impact loading. It was observed that the CFRP energy absorption capacity did not vary linearly with the drop hammerhead height and the optimum amount of CFRP-composite energy absorption capacity was governed by the amount of tensile steel bars.4. Proposed concrete damage scale model improved the concrete softening behavior in the descending branch of the stress-strain curve, and reduced the number of input parameters by 33-52% for the four concrete material models implemented in LS-DYNA software program.5. Proposed deployable honeycomb energy absorbers DEA-I, DEA-II, and DEA-III increased energy dissipation by 256 to 393% and mean crushing strength by 296 to 429%.

The Innerbelt Bridge (CUY-90-1524) carries Interstate Route 90 over the Cuyahoga River Valley in Cleveland, Ohio. The bridge was opened to traffic in 1959 and is a cantilevered steel deck truss with nine spans for a total length of 2,721 feet and a main span of 400 feet. Historically there have been several structural concerns with this particular bridge. Some of the concerns that have been noted are section loss due to corrosion, slope stability of the west bank, thermal strains due to inoperable expansion joints, and possible fatigue concerns due to out-of-plane vibrations in the web of a plate girder. The plate girder was added to widen the west end of the south side of the bridge.The research presented here will discuss four investigations into the condition of the bridge. The first investigation consisted of instrumentation and live load testing of several members. The purpose of the investigations was to assess the condition of the members and to validate a finite element model of the bridge. An investigation into out-of-plane vibrations in the web of a plate girder was then conducted. This investigation’s aim was to determine the cause of and severity of the vibrations. The third investigation consisted of monitoring the structure during repairs and modifications. Due to slope movement, the expansion joint located in Span 2 had “closed” and was inoperable. Several members were monitored during operations to “open” the expansion joint. The final investigation also involved structural monitoring. Several members were instrumented during the removal of the previously mentioned plate girder and the changes in the loads on the bridge were calculated. The results of this work were used to determine the condition and to aid in developing load ratings for the bridge. This work shows the importance of structural monitoring and investigation.

Water is universally recognized as a fluid and dynamic element, whereas architecture is perceived as a fixed and stable part of our surroundings. The negotiation of this tension between water and architecture provides an imaginative design opportunity. Architects tend to consider water merely as the primary enemy, tailoring design to keep it out of and away from buildings. This neglectful and narrowly technical attitude does not allow water to become a legitimate design element or constraint. The conventional role of water in architecture, as an aesthetic feature or an enemy, will be inverted to allow water to become a critical design constituent in the redesign of the Saint John ferry terminal on the Bay of Fundy. With nearly thirty-foot tidal changes, the terminal will allow this significant tide to penetrate the building, continually transforming the interior, as well as the exterior.