Integral abutment bridges (IABs) have performed successfully for decades and have demonstrated advantages over traditional, jointed bridges with respect to first cost, maintenance costs and service life. However, accurate prediction of IAB response to loading is complex and challenging; behavior is typically nonlinear due to the combined influence of thermal and long-term, time-dependent effects. Summarized herein are measured and computational results from examination of four interstate highway IABs located in central Pennsylvania. The collected data indicates that current AASHTO prediction methods are very conservative with respect to displacements. New computational models are used to perform a parametric study that considers the effects of seasonal thermal loading, thermal gradient, time-dependent material effects, abutment-backfill interaction and pile-soil interaction on deformations that occur over a 75-year bridge life. The measured and parametric study results provide a basis to establish an approximate method for predicting (1) maximum abutment displacement, (2) maximum bridge bending moments and (3) maximum pile moments over the bridge life.

The study of failures can help teach students how to ensure the satisfactory performance of buildings and bridges. A number of failure case studies have been developed for use in courses teaching reinforced concrete design, as outlined in the book “Beyond Failure.” These include failures in the construction process and in formwork, such as the Willow Island Cooling Tower. Some of the shear design provisions in current codes can be traced back to two collapses of Air Force warehouses in the mid-1950s. Three building collapses in the 1970s and 1980s showed the importance of punching shear. There is also much to be learned from reinforced concrete building performance under extreme conditions, such as the terrorist attacks on the Oklahoma City Murrah Building and the Pentagon (9/11). Another classic case is the collapse of a major section of the Ronan Point apartment towers in the UK in 1968, illustrating the need to properly tie precast building elements together. The collapse of the Laval, Quebec concrete bridge abutments in Canada shows the importance of providing continuity of reinforcement. This case study also offers the opportunity to illustrate the application of strut and tie models to analysis of complex reinforced concrete structures.

On major highways, bridge deck replacement often involves a diversion of traffic by shifting the travel lane adjacent to the repaired roadway. Thus, any traffic vibration or differential deflection, induced transversely due to truck traffic in the adjacent lanes, can affect the fresh concrete. Although there is very little evidence that traffic vibration in the adjacent lanes has affected the serviceability of concrete bridges in the past, more recently there have been some concerns about pouring high-performance concrete (HPC) in adjacent lanes because transverse cracking has been observed on newly repaired bridge decks. This paper examines the impact of traffic diversions and deflections that are induced transversely by truck traffic in adjacent lanes on the serviceability of bridge decks. In addition to field monitoring and laboratory testing, finite element analyses were used to simulate various bridge deck systems, traffic patterns, and truck loads to determine their effects on the serviceability of bridge decks. Results indicated that traffic loads and patterns can adversely affect the serviceability of concrete bridge decks. The results revealed that specific modifications to construction procedures and materials can significantly reduce the degree of transverse cracking in bridge decks.

The Oklahoma City Bombing is used as a case study to demonstrate how structural damage investigations can lead to code changes and improvements in design. This paper describes the use of seismic detailing to improve blast resistance. Such detailing has been incorporated into the soon to be published ASCE/SEI Standard on Blast Protection of Buildings.

The ACI 318-08 design code provides a direct computation method for deflection control of slender reinforced concrete beams. This method is based on the Navier-Bernoulli theory where shear deformations are presumed to be minimal. Using a database of twenty slender reinforced concrete beams with shear reinforcement, this paper reports on an analytical study which compared the service deflection predictions from the ACI 318-08 model, with predictions from a proposed MCFT-based sectional analytical deflection model and two MCFT-based numerical models, namely Response-2000 and VecTor2. The MCFT-based models all consider the deflection resulting from shear deformations in addition to the Navier-Bernoulli deflections. Emphasis in the study was placed on deflection predictions at the equivalent serviceability limit state for slender concrete beams longitudinally reinforced with either conventional or high strength steel and transversely reinforced with conventional stirrups. The results indicate that the ACI 318-08 deflection model can underestimate the service deflections by a large margin, especially for members with high transverse reinforcement ratios. The MCFT-based models gave results in better agreements with the test values for the full range of parameters studied. The average test-to-model deflection ratios were 1.77, 1.44, 1.50 and 1.09, and coefficients of variation were 23% 17%, 14% and 18%, for the ACI 318-08, Response-2000, VecTor2 and proposed MCFT-based sectional deflection models respectively.