Jaakko I. DietrichMikko A. InkalaVesa J. Maennistoe
p.3-8页
查看更多>>摘要：Reliable data on the condition of bridge networks are critical for successful bridge management. However, little attention has been paid to the quality of the data gathered in bridge inspections. This paper reviews the most important areas of bridge inspection that cause variation in bridge condition data and presents possible misjudgments made as a result of poor inspection data quality. The main elements of the inspection quality management system adopted in the Finnish Road Administration are presented, and the development of the quality of inspection data in 2002 and 2003 is briefly summarized. The evidence shows that the quality of inspection data has improved considerably but that the current quality level is not yet sufficient. The quality control system could be improved by increasing inspector interaction during control inspections, using an independent consultant in inspection quality measurements and inspector training, increasing the number of quality measurements, and introducing quality targets.
查看更多>>摘要：For more than 20 years, the FHWA has required that underwater inspection of bridges be performed at least every 5 years. Over that period, departments of transportation and other bridge owners have either developed in-house underwater inspection teams or hired outside consultants to perform this work. Ensuring that the inspections are conducted properly and accurately is critical. To this end, several policies and procedures can be implemented as quality control measures in an underwater inspection program. Selecting a properly trained inspection team, ensuring proper preparation before diving operations, conducting independent inspections, and looking at deterioration trends are several ways to ensure quality in underwater inspections.
查看更多>>摘要：To evaluate the effect of bonded versus unbonded condition in concrete overlay structure, a field evaluation, laboratory experiment, and 3-D finite element analysis (FEA) model were carried out. First, a field evaluation of bonded and unbonded pavement test sections in Iowa was performed. Cores were extracted from existing pavements and tested for their bond strengths with shear testing equipment. The bond strength between an overlay and the existing pavement gradually increased over time, regardless of the initial bond strength. In some cases, an insufficient bond shear strength at the interface between the concrete overlay and the existing pavement seemed to have contributed to increased distress on the overlay surface. Second, a laboratory experiment was conducted to investigate an effect of bonding in pavement structure. Concrete cylinder specimens that were one-half regular concrete and one-half polymer concrete were fabricated, and their indirect tensile strength was measured at the bonding interface. The experiment results indicated that polymer concrete samples exhibited higher indirect tensile strength than regular concrete samples at the interface. Finally, a 3-D FEA model using eight-node solid elements and a spring element was developed to quantify the bonding level. This model can simulate various bond levels from fully bonded to unbonded by a change of the stiffness of the spring element. The most appropriate spring stiffness was identified for different bonding conditions of overlaid pavements. A parametric study was conducted with spring stiffness changed to develop a matrix that can be used to quantify different levels of bonding. This matrix can help pavement engineers select the most appropriate spring stiffness for a given bonding condition and overlay thickness.
Joseph A. GuerreWilliam E. RobertAlison BradburyMichael Goodale...
p.27-34页
查看更多>>摘要：The Ministry of Transportation of Ontario (MTO), Canada, is currently implementing an asset management business framework (AMBF). The AMBF provides the ministry with an ambitious blueprint for incorporating asset management concepts into its existing business processes. A key component in the AMBF is the ability to integrate results from the ministry's existing management systems. In support of the AMBF, MTO has developed a prototype executive support system (ESS). The ESS is a what-if analysis tool that predicts network performance over time using data from the ministry's pavement and bridge management systems. It enables decision makers to evaluate the relationship between performance and budget and to view results by region, corridor, or functional class. This paper presents the analytical approach used to develop the ESS and describes how it was implemented by MTO. The ESS uses a candidate-based approach to system integration, which enables the integration of any management system capable of generating work candidates and estimating their impact on a defined set of performance measures. The ESS brings together data from these systems and performs an additional level of cross-asset economic optimizations, taking into account user-defined operating assumptions. Although much work has recently been done on the integration of pavement and bridge systems, the objective of this paper is to present a practical example implemented by MTO.
Teresa M. AdamsEmil JuniMohsin Khalid SiddiquiJames E. Dzienkowski...
p.35-43页
查看更多>>摘要：The Wisconsin Department of Transportation's (WisDOT) Bureau of Structures Data Consolidation Project brings together all bridge-related data into a single data warehouse, the Highway Structures Information System (HSIS), which includes inventory, inspection and maintenance records, and maintenance costs. With the new HSIS, WisDOT's interactive bridge inspection forms and data procedures became incompatible. This conflict presented a timely opportunity to investigate alternative data collection tools that would be practicable in the field. This paper investigates the use of alternative field data collection technologies for bridge inspectors. The participation of bridge inspectors in identifying functional requirements led to an assembly of field tools that included the tablet PC with a shoulder carrying case, a noise-canceling headset microphone, and a tethered pen. Bridge inspectors from six districts volunteered to train on the handwriting and speech recognition technologies and then to test the tools in the field. This paper presents the tool selection process, the technology choices assessed, the training of inspectors, the evaluation of the technology adoption, and the economic benefits of the new technology.
查看更多>>摘要：Before an optimal bridge management strategy can be determined in existing bridge management systems, there must first be a determination of the type and schedule of interventions to be performed on each element of the bridge to achieve a minimal-cost long-term steady state. Once these element-level strategies are known, they are grouped together, or bundled, to develop a management strategy for the bridge. This is currently done with a set of agency rules without regard to whether the bundle of interventions is optimal. Interventions are bundled because it is not desirable to perform interventions on the same bridge in successive years, principally because of user costs. The work discussed here uses inventory theory to bundle interventions on bridges optimally with multiple elements. Two examples are presented. Example 1 shows how a basic joint replenishment model can be used on a multielement bridge to determine optimal management strategies when interventions are bundled and a single-stage policy is used. Example 2 shows how a joint replenishment model with quantity discounts can be used to alleviate some of the problems with a basic joint replenishment model. The optimal management strategy determined in Example 2 is compared with the optimal management strategy determined when interventions are not bundled. Direction for future work is given.
Jianhua LiStephen T. MuenchJoe P. MahoneyNadarajah Sivaneswaran...
p.53-61页
查看更多>>摘要：The Highway Development and Management System (HDM-4) developed by the World Bank is a powerful pavement management software tool capable of performing technical and economic appraisals of road projects, investigating road investment programs, and analyzing road network preservation strategies. Its effectiveness is dependent on the proper calibration of its predictive models to local conditions. Although significant work has been done in calibrating and applying HDM-4 worldwide (especially in developing nations), no substantial effort has been made within the United States. This paper describes the calibration and application of HDM-4 (Version 1.3) to the Washington State Department of Transportation's (WSDOT) road network. WSDOT hopes to use HDM-4 to supplement its existing Washington State Pavement Management System (WSPMS) in long-term pavement performance and financial needs. Significant findings are that (a) HDM-4 can be used to analyze the WSDOT road network, (b) HDM-4 was successfully calibrated for the network, (c) the network requires calibration factors significantly different than HDM-4 default values, (d) software issues seem to prevent use of HDM-4 portland cement concrete pavement analysis, and (e) WSDOT can use HDM-4 to predict pavement preservation budgets quickly, select optimal preservation strategies under varying budget levels, and assist in determining the long-term effects of different funding scenarios on the road network.
查看更多>>摘要：Although the cost-effectiveness of preventive maintenance (PM) treatments for pavement is important, literature addressing this issue is limited. Even under the well-controlled FHWA long-term pavement performance (LTPP) study, incomplete data and sections exist Criteria for selecting PM treatments often conflict and have to be compromised. The multiple criteria decision-making (MCDM) method is one of numerous approaches available for resolving variations of results. The technique for order preference by similarity to ideal solution (TOPSIS), an MCDM method, was used to analyze successfully all 14 specific pavement study (SPS)-3 sites in Texas. The distress score (DS), international roughness index (IRI), and treatment costs were used as criteria to determine the cost-effectiveness of various PM treatments (thin overlay, slurry seal, crack seal, and chip seal). With TOPSIS, the cost-effectiveness of these treatments can be quantified, with variations caused by subjective judgment thus minimized. When all criteria were considered, the most and least cost-effective methods were chip seal and slurry seal, respectively. When cost was not considered, the most and least effective methods were chip seal and crack seal, respectively. The chip seals performed the best Chip seals had the most forgiving qualities of all the methods, and they yielded no reflection of the cracking that preceded the treatment applications. The evaluation based on TOPSIS provides a viable option for engineers determining the best PM treatments for pavement in need of maintenance.
查看更多>>摘要：A survey of U.S. public highway and road agencies that use chip seals as a part of their roadway maintenance program was developed and conducted to identify best practices in chip seal design and construction. A total of 72 individual responses from 42 U.S. states and 12 U.S. cities and counties were received; of those, nine respondents reported that they were getting excellent results from their chip seal programs. Those responses were grouped together and analyzed by the case study method to identify trends that lead to consistently excellent chip seal results. The study found that the successful chip seal programs had much in common. They use chip seals as a preventive maintenance tool, applying them to roads before distress levels were classified as moderate. They require their contractors to use the latest technology, and they exploit advances in material science such as the use of modified binders. And most of them use chip seals on both high- and low-volume roads.
Kelly L. SmithLeslie Titus-GloverMichael I. DarterHarold Von Quintus...
p.83-93页
查看更多>>摘要：The Arizona Department of Transportation (ADOT) has traditionally employed continuous pavement preservation as part of an overall design strategy to maintain the highest levels of service for highway users. Concerned about the effects of continual weakening of substructure material layers on preservation treatment cost and performance (i.e., more extensive and more frequent preservation activities), ADOT sponsored a study to determine the cost-effectiveness of the continuous preservation approach as compared with a reconstruction strategy. One goal of the study was to determine the break-even point for the two strategies (i.e., after how many rehabilitation treatments reconstruction becomes as cost-effective as continuous preservation). With inputs such as (a) service life estimates, (ft) best estimates of unit costs, (c) work zone-related user costs, and (d) the typical analysis period and discount rate used by ADOT, the total life-cycle costs for four alternative strategies were determined and compared for the 15 commonly occurring pavement scenarios in Arizona. The results of the analysis showed a consistent reduction in total life-cycle costs as the number of rehabilitation treatments performed between original construction and reconstruction increased from none to two. Results also showed that for nine of the 15 scenarios, total life-cycle costs associated with the third reconstruction alternative (two rehabilitations occurring prior to the first reconstruction event) were within 3% of the total life-cycle costs of the continuous preservation strategy. Hence, the break-even point occurs when two to three rehabilitation treatments are performed prior to reconstruction.
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