European Practice for Bridge Scour and Stream Instability Countermeasures

2000 ◽  
Vol 1696 (1) ◽  
pp. 236-243 ◽  
Author(s):  
David W. Bryson ◽  
Daniel G. Ghere ◽  
William H. Hulbert
Keyword(s):  
South Carolina ◽  
Filter Design ◽  
Bridge Scour ◽  
State Highway ◽  
The United Kingdom ◽  
River Geomorphology ◽  
River Training ◽  
State Highway Agencies ◽  
Stream Instability ◽  
Design And Construction

FHWA, AASHTO, and TRB sponsored a scanning review of European practice for bridge scour and stream instability countermeasures in October 1998. The review involved a panel of representatives from six state highway agencies (California, Illinois, Maryland, Minnesota, Oregon, and South Carolina), FHWA, two universities, and the private sector. The review included visits to hydraulic research laboratories, highway research institutes, and field sites in four countries—Switzerland, Germany, the Netherlands, and the United Kingdom. Findings during the scanning review can be classified as general observations and observations of specific countermeasures. General observations of European practice include design philosophy, risk analysis, environmental policy, river geomorphology, scour prediction, modeling, and inspection and monitoring. Observations of specific countermeasures include riprap design and construction, filter design and construction, river-training structures, riverbed degradation countermeasures, bioengineering, and flow-altering devices. These observations are contrasted with U.S. practice. The panel’s recommendations for modifying U.S. practice on the basis of the European experience and findings that deserve further evaluation are also presented.

Comprehensive Bridge Scour Evaluation Methodology

2000 ◽  
Vol 1696 (1) ◽  
pp. 204-208 ◽  
Author(s):  
P. F. Lagasse ◽  
E. V. Richardson ◽  
L. W. Zevenbergen
Keyword(s):  
United States ◽  
Highway Bridges ◽  
The United States ◽  
Annotated Bibliography ◽  
Evaluation Methodology ◽  
Bridge Scour ◽  
State Highway ◽  
Existing Bridges ◽  
State Highway Agencies ◽  
Stream Instability

In the United States, bridge scour technology is discussed primarily in three FHWA publications: Hydraulic Engineering Circular (HEC) 18: Evaluating Scour at Bridges; HEC-2: Stream Stability at Highway Structures; and HEC-23: Bridge Scour and Stream Instability Countermeasures. Together, these documents provide guidance to state highway agencies that is necessary for completing comprehensive scour and stream instability evaluations for the design of new bridges and for repairing existing bridges. Experience has shown that the relationships among the three documents are not always readily apparent, and some scour evaluations have relied primarily on HEC-18. A comprehensive flowchart that illustrates the interrelationship among the three FHWA scour-related documents has been developed. In addition, in 1998, FHWA, TRB, and AASHTO sponsored a scanning review of European practice for bridge scour and stream instability countermeasures. In 1999, ASCE published a compendium of papers on stream stability and scour at highway bridges, and FHWA prepared an annotated bibliography to support revisions to the three HECs. It is anticipated that the flow-chart and the substantial information from the scanning review, the compendium, and the annotated bibliography will be included in the next revisions to HEC-18, HEC-20, and HEC-23. On the basis of information from these sources, a comprehensive approach to bridge scour and stream instability evaluations is outlined, and an overview of planned revisions to the three FHWA HECs is provided.

Benefits of Compiling and Analyzing Hydraulic-Design Data for Bridges

2021 ◽  
pp. 036119812110237
Author(s):  
Stephen T. Benedict ◽  
Thomas P. Knight
Keyword(s):  
South Carolina ◽  
Bridge Scour ◽  
Hydraulic Characteristics ◽  
Bridge Design ◽  
Design Data ◽  
Data Set ◽  
Engineering Knowledge ◽  
Hydraulic Design ◽  
Strong Measure ◽  
Design Characteristics

The hydraulic design of bridges is a discipline that requires a strong measure of engineering judgment. Developing good engineering judgment can take years of experience, and generally increases one project at a time. A supplemental tool that can promote the development of engineering knowledge and judgment is to compile, analyze, and graphically present hydraulic data associated with stream and bridge-design characteristics from previously analyzed bridges. If the data set is sufficiently large, graphs developed from such an effort can provide the engineer with an enhanced picture of stream and bridge-design characteristics, helping them further develop their engineering knowledge and judgment. Furthermore, such graphs can function as project scoping tools and hydraulic-design review tools. Using selected data from approximately 300 bridge-scour studies in South Carolina, previously conducted by the U.S. Geological Survey, and limited hydraulic bridge-design data for approximately 200 bridges in South Carolina, trends in stream and bridge-hydraulic characteristics were evaluated including channel width, floodplain width, flood flow depths, stream slopes, bridge backwater, bridge flow velocity, and bridge lengths. Selected relationships are presented in this paper and should serve as a valuable tool for better understanding stream and bridge-hydraulic characteristics in South Carolina.

Using Artificial Intelligence to Estimate Nonlinear Resilient Modulus Parameters from Common Index Properties

2021 ◽  
pp. 036119812110237
Author(s):  
Laura Camarena
Keyword(s):  
Machine Learning ◽  
Material Properties ◽  
Resilient Modulus ◽  
Nonlinear Behavior ◽  
Machine Learning Techniques ◽  
Design Parameters ◽  
Nonlinear Parameters ◽  
State Highway ◽  
Learning Techniques ◽  
State Highway Agencies

The Mechanistic–Empirical Pavement Design Guide (MEPDG) considers a hierarchical approach to determine the input values necessary for most design parameters. Level 1 requires site-specific measurement of the material properties from laboratory testing, whereas other levels make use of equations developed from regression models to estimate the material properties. Resilient modulus is a mechanical property that characterizes the unbound and subgrade materials under loading that is essential for the mechanistic design of pavements. The MEPDG resilient modulus model makes use of a three-parameter constitutive model to characterize the nonlinear behavior of the geomaterials. As the resilient modulus tests are complex, expensive, and require lengthy preparation time, most state highway agencies are unlikely to implement them as routine daily applications. Therefore, it is imperative to make use of models to calculate these nonlinear parameters. Existing models to determine these parameters are frequently based on linear regression. With the development of machine learning techniques, it is feasible to develop simpler equations that can be used to estimate the nonlinear parameters more accurately. This study makes use of the Long-Term Pavement Performance database and machine learning techniques to improve the equations utilized to determine the nonlinear parameters crucial to estimate the resilient modulus of unbound base and subgrade materials.

Determining Minimum Contract Time for Highway Projects

2000 ◽  
Vol 1712 (1) ◽  
pp. 196-201 ◽  
Author(s):  
Jin-Fang Shr ◽  
Benjamin P. Thompson ◽  
Jeffrey S. Russell ◽  
Bin Ran ◽  
H. Ping Tserng
Keyword(s):  
Low Cost ◽  
Road User ◽  
User Cost ◽  
Time Curve ◽  
Highway Projects ◽  
The Road ◽  
State Highway ◽  
Florida Department ◽  
The Cost ◽  
State Highway Agencies

An increasing number of state highway agencies (SHAs) are using A (cost) + B (time cost) bidding ( A + B bidding) for highway construction. The A + B bidding concept is designed to shorten the total contract time by allowing each contractor to bid the number of days in which the work can be accomplished, in addition to the traditional cost bid. The SHA is then presented with the problem of determining a reasonable range of contract time submitted by the bidders. Most SHAs do not currently restrict the range of B. However, several problems may arise from an unrestricted range of B. First, if no minimum is set for B, a bidder may inflate the cost bid and submit an unreasonably low B, using the excess cost bid to cover the disincentives charged for exceeding the time bid. Second, if no maximum is set for B, then a bidder with a high B and a low-cost bid may be awarded the job and make an unreasonable amount of money from incentive payments. This study develops a quantified model of the price-time bidding contract. A construction cost-versus-time curve is developed from Florida Department of Transportation (DOT) data. The contractor’s price-versus-time curve is then combined with the road-user cost to determine the optimum lower limit to be set on B. Finally, several projects completed by the Florida DOT will be used to illustrate this model.

Pay Factor Analysis for Highway Pavements through Percentage of Material within Specification Limits and Monte Carlo Simulation

2021 ◽  
pp. 036119812110255
Author(s):  
Yunpeng Zhao ◽  
Dimitrios Goulias
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Operating Characteristic ◽  
Production Quality ◽  
Specification Limits ◽  
State Highway ◽  
Long Run ◽  
Similar Materials ◽  
Pay Factor ◽  
State Highway Agencies

Many state highway agencies (SHAs) have adopted pay adjustment provisions in their acceptance plans for construction and materials. In these payment adjustment acceptance plans, the percentage of material within specification limits (PWL) has been selected as the quality measure to relate production quality to pay factors, and pay equations are used to determine a pay factor for a lot based on PWL. Various pay equations have been proposed by the highway community for adoption in SHAs’ specifications. However, the effectiveness of these pay equations has not been fully evaluated. Another issue concerning the pay adjustment acceptance plans is the risk associated with single and multiple pay factors. The purpose of this study was to evaluate the effects of different pay equations commonly used by SHAs and the risks associated with pay adjustment acceptance plans. This was achieved by developing operating characteristic curves associated with various pay factors and expected pay curves and Monte Carlo simulation for assessing the effects in the long run. The methodology suggested in this paper is transferable elsewhere where similar materials and specifications are used for the acceptance of pavements.

Integrating Visualization into Structured Public Involvement: Case Study of Highway Improvement in Central Kentucky

2002 ◽  
Vol 1817 (1) ◽  
pp. 50-57 ◽  
Author(s):  
Keiron Bailey ◽  
Joel Brumm ◽  
Ted Grossardt
Keyword(s):  
User Satisfaction ◽  
Public Involvement ◽  
Systems Approach ◽  
Three Dimensional ◽  
Factors Affecting ◽  
State Highway ◽  
Advanced Technologies ◽  
Design Options ◽  
State Highway Agencies

Public involvement in transportation infrastructure decision making is frequently mandated and is regarded as increasingly essential by a wide variety of stakeholders. The integration of advanced technologies, such as visualization, into this process is increasingly desired. However, public involvement processes often are regarded as problematic by many stakeholders and the state highway agencies charged with implementing them. Structured public involvement (SPI) is posited. SPI takes a systems approach toward the integration of advanced technologies into public involvement forums. Because the goal of public involvement is to increase user satisfaction with both the process and the outcomes, the characteristics of advanced technologies and their capacities for gathering useful feedback in public forums must be evaluated. Visualization is put forth as an enabling technology within an SPI framework. The properties, capacities, and transportation-related uses of three visualization modes are evaluated, and their operational features are discussed. A case study dealing with highway improvement in central Kentucky reveals that three-dimensional renderings are significantly preferred to twodimensional and virtual reality modes; the case study also shows that visualization should complement, not replace, other performance information. The role of electronic scoring as an integral component of this SPI protocol is emphasized, resulting in fast assessment and free expression of views. Factors affecting the efficiency of visualization are analyzed, and recommendations are presented for implementing SPI protocols that rely on visualization. These include investigating participants' previous experience with visualization, incorporating iterative public involvement in finalizing design options, and ensuring that the technologies are compatible with the chosen public involvement process.

An evaluation of warranty contracting in the United States of America

2006 ◽  
Vol 33 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Mehmet Emre Bayraktar ◽  
Qingbin Cui ◽  
Makarand Hastak ◽  
Issam Minkarah
Keyword(s):  
United States ◽  
United States Of America ◽  
The United States ◽  
Department Of Transportation ◽  
Construction Costs ◽  
Advantages And Disadvantages ◽  
Contract Administration ◽  
State Highway ◽  
Early Failures ◽  
State Highway Agencies

It is believed that warranty contracting would benefit state highway agencies by improving quality, saving money and time, and encouraging contractors' innovations. However, the challenges associated with warranties could be substantial, including higher costs, early failures, a reduction or even elimination of small contractors from the bidding process, and an increase in contract disputes and litigation. The actual impact of warranty provisions on state Department of Transportation (DOT) projects in the United States of America is still unclear because of limited industry experience. This paper provides a detailed discussion of warranty provisions and the benefits and problems associated with the subject matter. The advantages and disadvantages of warranty provisions are evaluated from the conflicting perspectives of state Departments of Transportation (DOTs), contractors, and surety companies. The future prospects of warranty provisions are established based on the findings of a recent study of warranty provisions and existing literature. Also, several options are proposed that have a strong potential to improve the application of warranties on DOT projects.Key words: warranties, highway construction, innovation, highway maintenance, contract administration, construction costs, construction inspection.

Developing an Automated Technique to Calibrate the AASHTOWare Pavement ME Design Software

2020 ◽  
Vol 2674 (9) ◽  
pp. 867-877
Author(s):  
Shuvo Islam ◽  
Avishek Bose ◽  
Christopher A. Jones ◽  
Mustaque Hossain ◽  
Cristopher I. Vahl
Keyword(s):  
Goodness Of Fit ◽  
Optimization Technique ◽  
Model Verification ◽  
Statistical Testing ◽  
P Value ◽  
State Highway ◽  
Global Calibration ◽  
Automated Technique ◽  
State Highway Agencies ◽  
Pavement Me Design

Many state highway agencies are in the process of implementing the AASHTOWare Pavement ME Design (PMED) software for routine pavement design. However, a recurring implementation challenge has been the need to locally calibrate the software to reflect an agency’s design and construction practices, materials, and climate. This study introduced a framework to automate the calibration processes of the PMED performance models. This automated technique can search PMED output files and identify relevant damages/distresses for a project on a particular date. After obtaining this damage/distress information, the technique conducts model verification with the global calibration factors. Transfer function coefficients are then automatically derived following an optimization technique and numerical measures of goodness-of-fit. An equivalence statistical testing approach is conducted to ensure predicted performance results are in agreement with the measured data. The automated technique allows users to select one of three sampling approaches: split sampling, jackknifing, or bootstrapping. Based on the sampling approach chosen, the automated technique provides the calibration coefficients or suitable ranges for the coefficients and shows the results graphically. Model bias, standard error, sum squared error, and p-value from the paired t-test are also reported to assess efficacy of the calibration process.

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