Bridge Management for the 21st Century

2000 ◽  
Vol 1696 (1) ◽  
pp. 197-203 ◽  
Author(s):  
James E. Roberts ◽  
Richard Shepard

Bridge management has been a subject of intense interest and development for the past 10 years. In support of improved bridge management, FHWA funded the development of the Pontis bridge computer program, which is now in use by approximately 40 of the 50 states. In addition, many new guide specifications have been produced to assist bridge managers in their efforts to better manage the nation’s aging bridge inventory. The AASHTO Subcommittee on Bridges and Structures has taken the lead along with FHWA in implementing the improved bridge management systems. California and a few other states have been critical of the current ranking system for bridge maintenance and have been working to develop an improved performance measure. The bridge health index (HI), an improved and more comprehensive numerical rating system that uses the element inspection data to determine the remaining asset value of a bridge or network of bridges, is discussed. The HI is more consistent with the element-level evaluation data collected and reported in the Pontis program. Examples of the application of the HI are included.

Author(s):  
Glenn A. Washer ◽  
Mohammad M. Hammed ◽  
Paul Jensen ◽  
Robert J. Connor

Bridge inspection results provide input for several important functions such as maintenance, repair, and rehabilitation, bridge load capacity ratings, truck load routing/permitting, and future safety/condition predictions. As a result, the quality and reliability of inspection data are important for bridge management and to ensure the safety and serviceability of bridges. Element-level data collection has been required nationwide for bridges on the National Highway System since 2014, and therefore is relatively new to some bridge owners. The objective of the research reported here was to assess the quality of element-level bridge inspection data by comparing bridge inspection results between different bridge inspectors assessing the same bridges. This paper reports results from two research studies completed to collect data on the quality (i.e., variability) of element-level inspection data. Results of field trials indicated that there was significant variability in the data for bridge elements reported in the study. Based on these data, the element-level inspection results were widely dispersed—the smallest coefficient of variation calculated from the current studies was 18%, but typical values were found to be greater than 50% in most cases, and often greater than 100%. These data provide examples from a series of field trials that illustrate the need for improving the quality of element-level inspections to ensure the reliability of the data provided.


Author(s):  
Sylvester Inkoom ◽  
John O. Sobanjo ◽  
Paul D. Thompson ◽  
Richard Kerr ◽  
Richard Twumasi-Boakye

The AASHTO Pontis bridge management system has been used to support network-level and project-level decision making on the condition and functional obsolescence of bridges. State departments of transportation often develop bridge inspection data collection methods, deterioration models, cost models, and other preservation analysis capabilities to comply with the requirements of the federal Government Accounting Standards Board. The bridge health index (BHI) in the Pontis bridge management system has been used in the evaluation of the condition of bridges and elements at the project and network levels. This paper investigates three issues in the computation of the BHI: the effects of using linear and nonlinear scales for the condition state weights when computing the element health index (EHI); the application of amplification weights to EHI values to emphasize bridge elements in bad condition; and the development of element weights based on element replacement costs, element long-term costs, element vulnerability to hazard risks, and a combination of these measures. Historical condition data from element-based inspection were used to evaluate these effects at the network level.


Author(s):  
Sylvester Inkoom ◽  
John O. Sobanjo

As a concerted effort to improve the outcomes of bridge asset management, state highway agencies and Departments of Transportation (DOT) often improve their modes of bridge performance assessment using advanced deterioration models, optimized cost models, and other multi-objective preservation analysis in bridge monitoring processes. This paper attempts to utilize reliability importance index of a bridge component as a performance measure of the criticality of each element or subsystem to the entire bridge system. This paper investigates three major concepts regarding the importance of bridge elements: (i) the contribution of individual bridge elements to the overall reliability of the bridge system, (ii) the effect of critical elements on bridge deterioration, and (iii) the rank of the importance of elements and the potential economic consequence of their failure for optimal resource allocation. Computational methodologies are applied to legacy inspection data for bridges monitored over 20 years to evaluate the probability of failure of certain bridge elements. Based on the reliability importance criterion, the superstructure and substructure elements were considered to be critical to the survival of bridges. Bridge management and miscellaneous elements (such as expansion joints, railings, and sign structures), though important, did not generally contribute to the overall deterioration of the bridge.


2021 ◽  
Author(s):  
Gaowei Xu ◽  
Fae Azhari

The United States National Bridge Inventory (NBI) records element-level condition ratings on a scale of 0 to 9, representing failed to excellent conditions. Current bridge management systems apply Markov decision processes to find optimal repair schemes given the condition ratings. The deterioration models used in these approaches fail to consider the effect of structural age. In this study, a condition-based bridge maintenance framework is proposed where the state of a bridge component is defined using a three-dimensional random variable that depicts the working age, condition rating, and initial age. The proportional hazard model with a Weibull baseline hazard function translates the three-dimensional random variable into a single hazard indicator for decision-making. To demonstrate the proposed method, concrete bridge decks were taken as the element of interest. Two optimal hazard criteria help select the repair scheme (essential repair, general repair, or no action) that leads to minimum annual expected life-cycle costs.


Author(s):  
David V. Jáuregui ◽  
Kenneth R. White

The innovative use of QuickTime Virtual Reality (QTVR) and panoramic image–creation utilities for recording field observations and measurements during routine bridge inspections is reported. A virtual reality approach provides the ability to document a bridge’s physical condition by using different media types at a significantly higher level of detail than is possible in a written bridge inspection report. Digitally recorded data can be stored on compact disc for easy access before, during, or after an inspection. The development of a QTVR bridge record consists of four major steps: selection of the camera stations, acquisition of the digital images, creation of cylindrical or cubic panoramas, and rendering of the QTVR file. Specific details related to these steps are provided, as applied to various bridge inspection projects. The potential impact of QTVR on bridge management—in which routine inspection data are a factor in making decisions regarding the future maintenance, rehabilitation, or replacement of a bridge—is discussed.


2020 ◽  
Author(s):  
Moira Pryhoda ◽  
Rachel Wathen ◽  
Jay Dicharry ◽  
Kevin Shelburne ◽  
Bradley Davidson

The objective of this research was to determine if three alternative shoe upper closures improve biomechanical performance measures relative to a standard lace closure in court-based movements. NCAA Division 1 and club-level male athletes recruited from lacrosse, soccer, tennis, and rugby performed four court-based movements: Lateral Skater Jump repeats (LSJ), Countermovement Jump repeats (CMJ), Triangle Drop Step drill (TDS), and Anterior-Posterior drill (AP). Each athlete performed the movements in four shoe upper closures: Standard Closure, Lace Replacement, Y Wrap, and Tri Strap. Ground contact time, peak eccentric rate of force development (RFD), peak concentric GRF, peak concentric COM power, eccentric work, concentric work, and movement completion time were measured. Tri Strap saw improvements in four of seven biomechanical variables during CMJ and LSJ and one variable during TDS. Lace Replacement delivered improvements in one performance measure during CMJ, LSJ, and AP, and two variables in TDS. Y Wrap improved performance in three performance measures during LSJ and impaired performance in two measures during CMJ and three measures during AP. Tri Strap provided the most consistent performance improvements across all movements. This study allowed for the mechanical properties of the shoe lower to remain consistent across designs to examine if an alternative shoe upper closure could enhance performance. Our results indicate that increased proprioception and/or mechanical properties due to the alternative closures, especially Tri Strap, improves athlete performance, which concludes that the design of the shoe upper is an essential consideration in shoe design.


Author(s):  
Liting Lyu ◽  
Yadong Chu ◽  
Sufang Zhang ◽  
Yue Zhang ◽  
Qitian Huang ◽  
...  

Conversion of lignocellulosic biomass into lipids and related chemicals has attracted much attention in the past two decades, and the oleaginous yeast Rhodosporidiumtoruloides has been widely used in this area. While R. toruloides species naturally have physiological advantages in terms of substrate utilization, lipid accumulation, and inhibitor resistance, reduced lipid production and cell growth are noticed when biomass hydrolysates are used as feedstocks. To improve the robustness of R. toruloides, here, we devised engineered strains by overexpressing genes responsible for phenolic compound degradation. Specifically, gene expression cassettes of the manganese peroxidase gene (MNP) and versatile peroxidase gene (VP) were constructed and integrated into the genome of R. toruloides NP11. A series of engineered strains were evaluated for lipid production in the presence of typical phenolic inhibitors. The results showed that R. toruloides strains with proper expression of MNP or VP indeed grew faster in the presence of vanillin and 5-hydroxymethylfurfural than the parental strain. When cultivated in concentrated mode biomass hydrolysates, the strain VP18 had improved performance as the cell mass and lipid content increased by 30% and 25%, respectively. This study provides more robust oleaginous yeast strains for microbial lipid production from lignocellulosic biomass, and similar efforts may be used to devise more advanced lipid producers.


2010 ◽  
pp. 1488-1505
Author(s):  
Michael B. Knight ◽  
D. Scott Hunsinger

Research over the past few decades has identified that organizations have been faced with social/ economic pressure to utilize information technology and to facilitate communication via technological modes. These technology drive communications, under media richness theory, have been found to impact group cohesion and performance. The communications that are dependent on media richness are affected by individual user characteristics. Further group impacted by technology driven communication often experience varying levels of individual member agreeability, which further affect cohesion and performance. The individual users who participate in group projects must communicate, and ultimately can have different performance and cohesion outcomes based on the mode of communication used. This study identifies significant differences between groups, using specific media to communicate cohesion, the change in cohesion, agreeability and performance. Over the past few decades, organizations have faced increased pressure to utilize information technology (IT) to expand markets, to support increased communication between constituents, to streamline organizational decision making, and to improve employee productivity. Unfortunately, the results are contradictory as to the success IT has had in helping organizations achieve these goals. On one hand, several studies have reported beneficial returns on investment with the aforementioned implementation of information technology (Bourquard, 2004; Chienting, Jen-Hwa Hu, & Hsinchun, 2004; Dehning & Richardson, 2002; Hinton & Kaye, 1996; McGrath & Schneider, 2000; Violino, 1998; Willcocks & Lester, 1991). On the other hand, research also seems to suggest that technology can sink an organization when IT is not in alignment with the strategic goals of the organization (Arlotto & Oakes, 2003; Hinton & Kaye, 1996; PITAC, 1999; Violino, 1998; Willcocks & Lester, 1991). Adding to this dilemma, the marketplace has been turning to global expansion, becoming more demographically diverse, and relying more on the use of workgroups and teams (Stough, Eom, & Buckenmyer, 2000). These work teams historically have performed in homogenous settings and have met primarily face-to-face (FTF). These teams typically used little technology to interact. Lawler, Mohrman, & Ledford (1992) found that organizations that use teams more often have a positive outcome in decision making, employee trust and employee tenure. Considering the advances in communication media over the past twenty years, information technology has become a part of the everyday operations of most businesses. The requirement of the employee to use this technology has become essential to organizational success. With the organizational dependence on the employee to use information technology, plus the increased use of teams in the workplace, organizations may fail to provide workers with the support and training needed to develop cohesive groups resulting in improved performance and member satisfaction (Sarbaugh-Thompson & Feldman, 1998; Yoo, 2001). Several studies have concluded that teams that communicate successfully have had positive team performance (Rice, 1979; Tuckman, 1997; Zaccaro & Lowe, 1988). However, the independent variables considered in the aforementioned research vary greatly and seem to show inconsistency in identifying indicators that could be used to help with the implementation of technology that supports team performance. This study looks at face to face (FTF) and virtual teams, the personality trait of agreeability and the impact of specific communication technology on cohesion and performance. We use the media richness theory to facilitate our literature review and to guide the development of our hypotheses.


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