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Previous research conducted multiple levels of laboratory tests and analytical studies and designed an innovative joint to resist joint cracking on the longitudinal joint between box girders. The joint design was165 mm (6.5 in.) wide and filled with shrinkage-compensating concrete and reinforced with transverse steel bars. Although the previous laboratory test and analytical simulation results indicated that the joint showed superior performance when resisting the joint early-age cracking and maintained the integrity of the bridge superstructure, its performance on a real onsite bridge was not evaluated. This paper documented the field evaluation of this new design on a single span box beam bridge. A bridge in Washington County, Iowa was selected to deploy the joint. To evaluate the performance of this first implementation, a 7-day field monitoring campaign was conducted during the early-age of the joint material. In addition, a live load field test and two bridge inspections at 6-month intervals were performed. During the field tests and monitoring work, temperature, strain, and displacement data were collected at critical locations and analyzed to evaluate the joint functionality on cracking resistance and load distribution. The visual inspections were conducted and focused on the condition and performance of the joint with a specific interest in the development of any cracking. The results indicated that this new joint was well suited to resist early-age joint longitudinal cracking, which is common in other joint designs. The joint was efficient in load distribution and the bridge superstructure behaved as an integral structure when the live load was placed. In addition, with an integral abutment, the construction of the abutment affected the strain distribution in the joint near the joint ends. This effect tended to provide compression in the transverse direction and reduced the potential of joint cracking. This paper documents the field evaluation of the new design of a longitudinal joint between concrete box beams on a bridge in Washington County, Iowa. The joint was 165 mm (6.5 in.) wide and filled with shrinkage-compensating concrete and reinforced by transverse steel bars. The results indicated that this new joint was well suited to resist early-age joint longitudinal cracking, which is common in other joint designs. The joint was efficient for load distribution. The bridge superstructure behaved as an integral structure when the live load was placed. In addition, with an integral abutment, the construction of the abutment affected the strain distribution in the joint near the joint ends. This effect tended to provide compression in the transverse direction and reduced the potential of joint cracking. This design is recommended to be used in concrete box beam bridges to prevent longitudinal joint cracking and reduce the potential of bridge superstructure deterioration, especially in rural regions. Further research is recommended to deploy the design on a bridge with a higher traffic volume to investigate the performance of the joint under larger traffic loads. [ABSTRACT FROM AUTHOR]

The interaction between the bike-sharing behavior and public transportation system is still not fully understood. This paper aims to explore the impacts of public transportation disruption on the bike-sharing behavior utilizing the metro shutdown case inWashington, DC, in 2016. Multisource data, including bicycle trip and geographic information, was collected before, during, and after the public transportation disruption. Through the spatial-temporal analysis, it is a recurrent pattern for bike-sharing members to take their trips on weekdays and the casual users without membership to take the trips on weekends. Moreover, it is noted that the bike-sharing trips for casual user increased 191% and the variation of trip duration is insignificant on metro shutdown day. The bike-sharing stations adjacent to the metro lines are found to experience a higher trip increase. Furthermore, the complex network approach was employed to explore the bike-sharing network properties. In network perspective, the connectivity of bike-sharing network has increased due to the shifted travelers. In addition, the modularity maximization approach was also introduced to infer the community structure of bike-sharing network. The results suggest the disruption strengthen the interaction between central clusters and outer clusters. Implications for further research, policy, and design are discussed. [ABSTRACT FROM AUTHOR]

The estimation of seismic forces for acceleration-sensitive nonstructural components (NSCs) in buildings including architectural, mechanical, and electrical systems and building content requires a reliable prediction of the seismic floor accelerations along the building height. These accelerations can be estimated either by performing detailed time-history dynamic analyses on a finite-element model of the supporting building or by using simplified equations as proposed in the North American and European codes. In addition, a probabilistic estimate of floor acceleration demands is essential for risk-informed performance assessment and loss estimation of these NSCs. To this end, an analytical method for the prediction of peak floor acceleration demands was proposed in FEMA-P58 [ATC (Applied Technology Council). 2012. Seismic performance assessment of buildings, prepared for federal emergency management agency. FEMA-P58. Washington, DC: ATC] based on linear and nonlinear time-history analyses performed on idealized low-to-medium-rise building models. This paper presents a validation study of the FEMA-P58 equation using two databases of recorded horizontal rooftop accelerations in 41 instrumented buildings. The first database consists of 28 buildings that were subjected to different earthquake events in California, while the second database consists of 13 buildings that were subjected to the 2011 Tohoku earthquake in Japan. The ratios of the recorded rooftop-to-ground-level accelerations in both databases were computed and compared to the FEMA-P58 predictive equation. A comparison of predicted versus recorded median and dispersion of the rooftop acceleration amplification was made and discussed. The results showed that the equation underestimated the acceleration amplification for frame buildings. [ABSTRACT FROM AUTHOR]

The Cabin John Bridge (CJB), located just outside Washington, D.C., is a masonry arch with a central angle of 110°, an intrados radius of 40.9 m (134 ft), and a span of 67 m (220 ft). Construction of the bridge began in 1857 but was not completed until late in 1863 because of suspensions due to lack of appropriations and the Civil War. The CJB is part of the Washington Aqueduct (WA) and is still the longest single-span masonry arch in the United States. The bridge was designated a National Historic Civil Engineering Landmark by the ASCE in 1972. The paper provides context for the bridge design and explains the construction technologies that were used. In the process, French and British influences on American masonry arch design practices at mid-19th century are revealed. The respective roles of Captain Montgomery C. Meigs, the chief engineer of the WA, and Alfred Landon Rives, his assistant engineer, are critically assessed. The paper provides, for the first time, relevant facts on Rives’ education and engineering career. The performance of the bridge over 145 years is reviewed and discussed. [ABSTRACT FROM AUTHOR]

This paper reports on results of research conducted at the University of Washington to investigate the means and methods for overcoming barriers to the implementation of Web-based project management systems (WPMS), and to develop a set of best practices in both the United States and Japanese construction industries. The United States and Japanese economies are high-tech intensive and both cultures have embraced technology. However, a relatively small sector of the construction industry in each country has implemented WPMS. The question posed here is why have these drivers not resulted in the industry’s adoption of this new technology, and further, perhaps there are lessons learned from those who have successfully implemented WPMS. This research seeks to broaden our understanding of implementation barriers that are limiting the use of WPMS tools as well as means and methods of overcoming those barriers based on successful implementation in both countries. [ABSTRACT FROM AUTHOR]

An extensive treatability study was completed on a chlorobenzene-rich nonaqueous phase liquid (CB-NAPL) impacted source zone at an active industrial site. A baseline leaching condition for the low permeability silty site soils was established via one-dimensional (1D) semidynamic leach testing on undisturbed and remolded core samples using EPA 1315 modified (M) [Method 1315 – mass transfer rates of constituents in monolithic and compacted granular material using a semidynamic tank leaching procedure, revision 1. Washington, DC: EPA. Office of Resource Conservation and Recovery] for use with hydrocarbons under zero headspace conditions in a new, specially designed apparatus. Comparison of the most heavily impacted samples (average of 2,932 to 9,422 mg/kg CB) indicated that the EPA 1315M 1D leaching response was typically within a factor of two when comparing undisturbed versus remolded (homogenized) samples. Even though soil homogenization may have changed the initial soil fabric and contaminant distribution, the comparable outcomes suggested that it may be sufficiently accurate to work with remolded samples given the many challenges and uncertainties associated with undisturbed cores. In addition, CB leaching rates were observed to be more closely associated with total CB content than hydraulic conductivity (K) for samples characterized by K < 1 × 10−6 cm/s. This is perhaps not surprising since the concentration gradient is the key driver for mass transfer in diffusion-controlled media. Comparison of the EPA 1315M leaching results from an untreated, undisturbed silty soil layer from the hotspot location to the leaching results of a stabilization/solidification (S/S)-treated soil homogenized over the full treatment depth showed CB percent leaching reductions (%LRs) of approximately 85.5% for the contract-specified laboratory-based mix design and 74.5% for a field quality assurance (QA) sample taken during remedial construction. These %LR values for the S/S treatment were considerably lower than the calculated %LR of >99% using EPA 1316M on the most heavily impacted sand sample from the hotspot location. This discrepancy in perceived performance prompted a discussion on the appropriate use and limitations of the %LR framework for assessing S/S performance and stressed the importance of properly designating the principal threat waste condition as that hotspot location/interval characterized by the greatest contaminant mobility. [ABSTRACT FROM AUTHOR]

Bubbles entrained by spilled water at hydroelectric projects increase the concentration of total dissolved gas (TDG), which may lead to gas bubble disease in fish. In this paper, the TDG dynamics downstream of Wells Dam are investigated using a two-phase flow model that accounts for the effect of the bubbles on the flow field. The TDG is calculated with a transport equation in which the source is the bubble/liquid mass transfer, a function of the gas volume fraction and bubble size. The model uses anisotropic turbulence modeling and includes attenuation of normal fluctuation at the free surface to capture the flow field and TDG mixing. The model is validated using velocity and TDG field data. Simulations under two plant operational configurations are performed to gain a better understanding of the effect of spill operations on the production, transport, and mixing of TDG. Model results indicate that concentrated spill releases create surface jets that result in the lowest TDG concentration downstream. On the other hand, spreading the spill release, with moderate flow through each gate, produces the highest TDG values downstream as a result of more air available for dissolution and smaller degasification at the free surface. [ABSTRACT FROM AUTHOR]

The use of glass fiber-reinforced polymer (GFRP) bridge decks is appealing for applications where minimizing dead load is critical. This paper describes fatigue and strength testing of two types of GFRP decks being considered for use in the retrofit of an aging steel arch bridge in Snohomish County, Washington, where a roadway expansion is necessary and it is desirable to minimize the improvements to the arch superstructure. Each test used a setup designed to be as close as practicable to what will be the in situ conditions for the deck, which included a 2% cross slope for drainage. The fatigue testing consisted of a single 116 kN (26 kip) load applied for 2 million cycles, which corresponds to an AASHTO HS-25 truck with a 30% impact factor, and the strength testing consisted of multiple runs of a monotonically applied minimum load of 347 kN (78 kips). Results from the fatigue testing indicated a degradation of the stiffness of both deck types; however, the degradation was limited to less than 12% over the duration of loading. Further, the results showed both deck types accumulated permanent deck displacement during fatigue loading and one deck type used a detail with poor fatigue performance. That detail detrimentally impacted the overall deck performance and caused large permanent deck deformations. It was also found that degradation of composite behavior between the deck and girders occurs during fatigue loading and should be included in design. [ABSTRACT FROM AUTHOR]

Capping is a common remediation technology for the containment/stabilization of contaminated sediments. During capping activities, clean material is commonly released from a barge at the water surface and falls through the water column to the sediment surface, providing an uncontaminated surface sediment layer. Little information exists on the potential release of in situ contaminated sediments during and after capping operations. This paper focuses on the measured release of contaminants during capping events at Boston Harbor, Mass. (confined aquatic disposal cells for contaminated sediment) and Eagle Harbor, Wash. (creosote-contaminated sediment from a wood treating facility). The water column was sampled during capping events to evaluate whether cap placement resulted in the release of polycyclic aromatic hydrocarbons (PAH)- or polychlorinated biphenyls (PCB)-contaminated sediments at Boston Harbor, or PAH-contaminated sediments at Eagle Harbor. Though results at both sites indicated some contaminant resuspension during capping operations, in general contaminant resuspension was relatively low for all capping events. PCB and PAH concentrations for most samples were in the low ng/L range. The most significant releases occurred when previously uncapped sediments were initially capped, and the magnitude of contaminant resuspension decreased with successive capping layers. These results may have important implications regarding sediment cap installation techniques and their potential impacts on water quality. Resuspension during capping may be minimized by placing cap material in lifts, where the first lift provides a uniform layer of clean material using techniques that minimize sediment disturbance and subsequent lifts are placed more aggressively once contaminated sediment is covered. [ABSTRACT FROM AUTHOR]

This study evaluates the laser in situ scattering and transmissometry (LISST) instrument LISST-SL2, a laser diffraction instrument for suspended sediment sampling in rivers, with concurrent physical measurements of suspended sediment concentration (SSC) and particle size distribution (PSD) as well as velocity measurements by an acoustic Doppler current profiler (ADCP). We collected 136 LISST-SL2 samples along with 61 physical samples for SSC measurement, of which 24 physical samples included PSD measurement during 2018–2020 from 11 sites in Washington state and Virginia. An effective density is required to convert the measured volumetric SSC by the LISST-SL2 into a reported mass SSC, and by default the LISST-SL2 assumes a value of 2.65 g/mL. From our data set, we computed effective densities (mass SSC/volumetric SSC) that ranged from 0.5 to 5.4 g/mL , with a best-fit value of 2.05 g/mL. Additionally, the LISST-SL2 was not able to measure the finest sediment sizes in suspension, which affects the resulting PSD. Therefore, we propose some adjustments of the LISST-SL2 data with a supporting physical sample to account for these effective density and PSD issues. When doing so, we were able to reduce the root-mean square relative error (RMSRE) to 18% from 117% for SSC, and to 26% from 78% for PSD. LISST-SL2 velocities were generally higher than ADCP velocities with a 21% RMSRE. Our results and guidance will allow for more accurate sampling by the LISST-SL2, which has potential for studying spatial and temporal variation of suspended sediment characteristics in rivers. [ABSTRACT FROM AUTHOR]

The article discusses the highlights of the Fifth Congress on Forensic Engineering in Washington, D.C. from November 11-14, 2009. Among the topics discussed by speakers were temporary structures, construction phase failures and building envelope performance. A panel discussion centered on ethics and the expert witness. The event was attended by several technical committees including the Education Committee and the Committee on Forensic Practices.

Accurately identifying traffic crash risk factors is an important way to improve freeway safety. The purpose of this research is to reveal the internal coupling mechanisms of and differences between freeway traffic crashes in various area types, as well as to overcome the defects of compatibility and accuracy in the application of conventional data mining algorithms toward road traffic safety. First, the area types were divided into urban, suburban, and mountainous freeways in this research, based on the UW-DRIVENet (Digital Roadway Interactive Visualization and Evaluation Network, University of Washington) transportation big data platform, where data of more than 30,000 traffic crashes in Washington state in 2016 were extracted. The data set was designed via six dimensions: people, vehicle, road, environment, crash, and time. Furthermore, the weighted orientated multiple dimension interactive Apriori algorithm (WOMDI-Apriori) was proposed. In this improved algorithm, a subjective and objective joint weighting model based on interval analytic hierarchy process (IAHP) and gray relational degree was applied to quantify the weight of data fields. Finally, regarding three different area types of freeways, the improved algorithm was adopted to mine the association rules from the perspective of multidimensional interaction: full mapping crash cause and crash dimension autocorrelation perspectives. The results revealed the differences in traffic crash causes and risk factors of cross-freeways. The results show that the accuracy of the improved WOMDI-Apriori algorithm is 82.7%, 88.5%, and 80.5% higher than that of the conventional Apriori association rule algorithm when applied to urban, suburban, and mountainous area freeways, respectively, which indicates that WOMDIApriori algorithm can better reveal the causes of freeway traffic crashes and identify crash precursors more accurately. In conclusion, the WOMDI-Apriori algorithm proposed in this research can be used as an effective approach for risk identification of freeway traffic crashes and can also provide theoretical guidance for future freeway traffic safety improvement. DOI: 10.1061/JTEPBS.0000698. © 2022 American Society of Civil Engineers. [ABSTRACT FROM AUTHOR]

Provides information on a conference on 'Technology, Market Liberalization, and Infrastructure' that will be held in January 2003 in Washington D.C. Banks and organizations that collaborated for the conference; Background on the conference; Research topics.

For determining highly disaggregate details about traffic dynamics, microscopic traffic simulation has long proven to be a valuable tool for the evaluation of development plans and operation/control strategies. With recent advances in computing capabilities, research interest in large-scale microscopic simulation has never been greater. This case study develops a 24-h large-scale microscopic traffic simulation model for theWashington, DC, metropolitan area. The model consists of over 7,000 links, 3,500 nodes, 400 signalized intersections, and over 40,000 origin-destination pairs. Various field measurements, such as time-dependent traffic counts and corridor travel times, have been used for model calibration/validation. The EPA's Motor Vehicle Emission Simulator is linked with the microscopic simulation model for the estimation of environmental impacts. The calibrated model system has been used to comprehensively evaluate a newly built toll road in Maryland, the Intercounty Connector. Various network-level and corridor-level performance measures are quantified. The case study demonstrates the feasibility and capability of large-scale microscopic simulation in transportation applications. It establishes an example for modelers and practitioners who are interested in constructing a large-scale model system. The developed 24-h simulation model system of traffic and emissions has the potential to serve as a test bed for integration with other analysis tools, such as behavioral and optimization models. [ABSTRACT FROM AUTHOR]

Travel speed ties directly to travel time, so it is an important measure for quantifying arterial performance. However, accurately estimating link travel speed for urban arterials is difficult because of traffic fluctuations and stop-and-go conditions caused by signal control. This research proposes a two-step empirical approach to effectively estimate the link-journey speeds using only advance loop detector outputs. The first step is to estimate the spot speed on the basis of advance loop measurements using Athol's algorithm. The robust regression technique can be used to calibrate the speed estimation parameter (or -factor) in Athol's algorithm. The second step is to use the proposed simplified speed estimation model to estimate the link speed using only the calculated loop-spot speed without any knowledge of signal timing plans. Traffic operations in the central business district of the City of Bellevue, Washington, are simulated in the VISSIM traffic simulation model. The test results show that only 50 cycles of data are needed to calibrate the -factor in loop-speed estimation and the same datasets can be used to calibrate the proposed link-speed model. Using this model, the average mean absolute error over the study links is reduced from 4.24 to 1.51 mph. With proper calibration, this average error can be further reduced to 0.91 mph. The results are encouraging and satisfactory. The results also show that the accuracy of speed estimation may be further increased when more data are applied for calibration. [ABSTRACT FROM AUTHOR]

A biography of Brigadier General Thomas Lincoln Casey of the U.S. Army Corps of Engineers is presented. He was born May 10, 1831 in Sackets Harbor, New York and studied at the U.S. Military Academy at West Point, New York. He was assigned to work at the construction of Fort Delaware, Delaware as an assistant engineer after his graduation at the academy. During his tenure as civil engineer, his accomplishments include the reconstruction of Washington Monument in Washington, D.C.

There are an estimated 11 million illegal immigrants currently residing in the United States. Of this population, research shows that approximately 19% work in the construction industry, comprising around 14% of all construction workforces. The main objectives of this research are to (1) to predict possible effects of immigration and immigration reform legislation on worker wages and (2) to assess the likely wage increase due to decreased supply of immigrant labor. In the Washington, D.C. metropolitan region, the construction workforces for low-skilled trades such as concrete, masonry, drywall, painting, flooring, and roofing are comprised of approximately 55% illegal immigrant. Based on four factors evaluated in this research (1) prevailing wage provision in legislation; (2) forced tax compliance of the workforce; (3) market correction from currently depressed wages due to immigrant penetration into the workforce; and (4) a labor shortage resulting from a depleted supply of immigrant labor, proposed legislation could increase the cost of trade labor up to almost 70% in the Washington, D.C. metropolitan area. Overall labor costs for projects could increase by almost 18%, and total project costs could rise almost 12% in the Washington, D.C. metropolitan region. [ABSTRACT FROM AUTHOR]

There are an estimated 11 million illegal immigrants currently residing in the United States. Of this population, research shows that approximately 19% work in the construction industry, comprising around 14% of all construction workforces. The Washington, D.C. metropolitan region has a unique makeup of workforces within the construction industry. Between September 2006 and February 2007, 896 construction workers from several projects in the Washington, D.C. metropolitan area participated in a survey. The study targeted the low-skilled, immigrant-saturated trades in construction. The most compelling finding in this study was that illegal immigrants make up a far greater proportion of the construction workers in low-skilled trades than indicated by national averages, 55% as compared to between 20 and 36% nationally. This will increase the impact of immigration and immigration reform substantially for the Washington, D.C. metropolitan. [ABSTRACT FROM AUTHOR]

Four in situ experiments on sediment erosion characteristics were conducted at the Anacostia River that runs through Washington, D.C. Supplemental erosion rate data were also obtained by carrying out five laboratory experiments using sediment samples collected at the field. In laboratory experiments, the sediment samples were mixed with tap water and placed in the flume to form beds for finding the difference in terms of erosion characteristics caused by different sediment composition among the five samples. This approach enables the finding of erosion characteristics for the entire tidal Anacostia River with limited resources. The in situ measured critical bed-shear stresses τcr for erosion at the water-sediment interface z=0 varies from 0.03 to 0.08 Pa. Field results indicated that τcr(z) increases with the depth z and becomes more than 0.6 to 0.7 Pa with an erosion thickness of less than 1 cm. Sediment beds prepared at a laboratory appear having an upper limit on how much τcr(z) can be developed. [ABSTRACT FROM AUTHOR]

Presents proceedings from the Roebling Lecture on the construction of the Ronald Reagan Building in Washington, D.C., delivered at the Construction Institute's Atlantic Coast Construction Conference in May 2004. Financial arrangement for building construction under the Federal Triangle Development Act; Estimated cost of the construction; Tenancy plan for the building; Principles followed in federal building construction.

The foundations contract for replacement of the Woodrow Wilson Bridge near Washington, D.C., presented an opportunity to profit from partnering. This article tells why partnering was necessary, the techniques used, and some payoffs. The contract had disincentive payments, potential for differing site conditions, community constraints, and untested relationships. Regular meetings and a monthly questionnaire facilitated partnering, trends and comments were analyzed monthly to keep on track, and both parties went beyond contract requirements to succeed. Partnering belongs in any major acquisition program’s toolkit. [ABSTRACT FROM AUTHOR]

Presents a study which used a multiobjective system analysis to size reservoir storage and identify noninferior system operating rules that mitigate the impacts of consumptive appropriations in the Potomac River in Washington, D.C. Parametric operating rules; Policy implications; Conclusions.

Discusses the implications of a study focusing on the urban freeway in the Maryland suburbs of Washington, D.C. Details on Maryland's smart growth program, which is aimed at containing urban sprawl and focusing growth in preferred areas; Information on the Intercounty Connector freeway; Issues that transportation engineers must confront in meeting the challenges of smart growth.

The article discusses the District of Columbia Green Building Act of 2006. The Act's central feature is the adoption of the Leadership in Energy and Environmental Design (LEED) Green Building Rating System of the U.S. Details on the Act's implications for sureties, and some definitions and basic assumptions of the Act are also discussed in the article.

Presents an essay on the experience of an engineer attending the Transportation Research Board convention in Washington, D. C. Description of the hotel where the engineer stayed; Theories on how the engineer ended up in an expensive suite.

A Bayesian chemical mass balance (CMB) model was used to identify the sources of heavy metals in a highly urbanized area at the vicinity of the Anacostia River in Washington, DC. This method uses the elemental profiles of potential sources and the storm water runoff samples at two outfalls into the Anacostia River to infer the contribution of each source by providing the joint probability densities of the contribution of each source and the credible intervals of the inference. For this purpose, the potential sources of heavy metals in the urban catchment were identified and multiple samples of each were collected and analyzed by using an inductively coupled plasma mass spectrometry technique to determine their elemental profiles. Next, a Bayesian CMB method was employed to infer the contribution of various sources to the storm water runoff. The results of the analysis revealed that paved surfaces that accommodate traffic (i.e., street, bridge, and parking lot) are the major contributors to both dissolved and particulate metals in storm water. It was also found that for both dissolved fraction and total pollutants, the wet deposition source has a small contribution to all elements and that the runoff originating from roofs can be responsible for up to 50% of the Pb in the storm water. [ABSTRACT FROM AUTHOR]

The article reports that Dr. G. Edward Gibson, Jr. is the new Specialty Editor of Project Planning and Design group and acknowledge Dr. Gunnar Lucko's considerable effort in serving as Acting Specialty Editor since February 2007 and stays as a permanent Assistant Specialty Editor. Gibson is a Professor and the Garry Neil Drummond Endowed Chair in the Department of Civil, Construction, and Environmental Engineering (CCEE) at the University of Alabama at Tuscaloosa. Lucko is an Assistant Professor of Civil Engineering and the Director of the Construction Engineering and Management Program at The Catholic University of America (CUA). More information about the two scholars and their institutions are also discussed.