scholarly journals Canadian highway bridge evaluation: reliability index

1992 ◽  
Vol 19 (6) ◽  
pp. 987-991 ◽  
Author(s):  
D. E. Allen
Keyword(s):  
Reliability Index ◽  
Life Safety ◽  
Highway Bridge ◽  
Traffic Network ◽  
Structural Behaviour ◽  
Effective Manner ◽  
Bridge Evaluation ◽  
Safety Considerations ◽  
Existing Bridges ◽  
Economic Considerations

So that the limited funds available for bridge upgrading can be spent in the most effective manner, the reliability index assumed for evaluation of existing bridges requires a closer definition than that assumed for the design of new bridges. A reliability index which varies between 2.0 and 3.75 is determined for bridge evaluation in Clause 12 of CAN/CSA-S6-88 on the basis for life-safety considerations and calibration to experience. The reliability index is chosen by the evaluator as a function of structural behaviour, level of inspection and evaluation, and traffic situation for which the evaluation is made, all of which affect life safety. Economic considerations are also taken into account; the highway authority may, however, wish to increase the values of the reliability index for critical bridges whose failure seriously affects the traffic network. Key words: bridge evaluation, reliability index, life safety, economics.

A CASE FOR ADDING AN INSPECTION LEVEL RELATED TO SHM FOR BRIDGE EVALUATION

2020 ◽  
Author(s):  
Aftab Mufti ◽  
Farnaz Raeisi ◽  
Huma Khalid ◽  
Andy Horosko ◽  
Baidar Bakht
Keyword(s):  
Human Life ◽  
Highway Bridge ◽  
Load Carrying Capacity ◽  
Design Code ◽  
Optimum Load ◽  
Target Reliability Index ◽  
Bridge Evaluation ◽  
Load Carrying ◽  
Vehicle Loads ◽  
Existing Bridges

The Canadian Highway Bridge Design Code (CHBDC) uses the concept of a target reliability index for evaluating the load carrying capacity of existing bridges. This index, which is based on risk to human life, relates to three aspects of uncertainties inherent in a bridge; (a) element behaviour, (b) system behavior, and (c) inspection level, where the inspection level currently refers to only manual inspections. Citing examples of tests on many instrumented bridges, the paper proposes an additional inspection level for inspections done with the help of electronic instruments and tests under controlled vehicle loads. The paper proposes simple additions to clauses of the CHBDC, for use when determining the optimum load carrying capacities of existing bridges where structural health monitoring (SHM) information is available.

scholarly journals Load testing of Highway Bridge

2018 ◽  
Vol 196 ◽  
pp. 02020 ◽  
Author(s):  
Petra Bujňáková ◽  
Jozef Jošt ◽  
Matúš Farbák
Keyword(s):  
Static Load ◽  
Highway Bridge ◽  
Load Carrying Capacity ◽  
Load Testing ◽  
Construction Process ◽  
Structural Behaviour ◽  
Box Girder ◽  
Load Carrying ◽  
Predicted Model ◽  
The City

New segmental concrete bridge has been built near the city Žilina, aligned on European highway corridor E 50. The bridge is composed of the two separate precast prestressed box girder structure constructed by balanced cantilever method. The total length of both structures is 1042 m. The similar superstructure consists of a total of eighteen continuous spans with main spans of 60.5 m. The construction process, load carrying capacity and monitoring of the bridge has been investigated before the opening of the bridge. The paper presents verification of the structural behaviour of the bridge under static load compared to predicted model for both precast prestressed structures.

scholarly journals Comparison and calibration of numerical models from monitoring data of a reinforced concrete highway bridge

2013 ◽  
Vol 6 (1) ◽  
pp. 121-138 ◽  
Author(s):  
R. G. M. de Andrade ◽  
L. M. Trautwein ◽  
T. N. Bittencourt
Keyword(s):  
Numerical Models ◽  
Structural Behavior ◽  
Highway Bridge ◽  
Structural Behaviour ◽  
Short Term ◽  
Financial Investments ◽  
Structural Solutions ◽  
Term Monitoring ◽  
Highway System

The last four decades were important for the Brazilian highway system. Financial investments were made so it could expand and many structural solutions for bridges and viaducts were developed. In parallel, there was a significant raise of pathologies in these structures, due to lack of maintenance procedures. Thus, this paper main purpose is to create a short-term monitoring plan in order to check the structural behavior of a curved highway concrete bridge in current use. A bridge was chosen as a case study. A hierarchy of six numerical models is shown, so it can validate the bridge's structural behaviour. The acquired data from the monitoring was compared with the finest models so a calibration could be made.

Canadian highway bridge evaluation: derivation of Clause 12 of CAN/CSA-S6-88

1992 ◽  
Vol 19 (6) ◽  
pp. 1007-1016 ◽  
Author(s):  
F. Michael Bartlett ◽  
Peter G. Buckland ◽  
D. J. Laurie Kennedy
Keyword(s):  
Key Words ◽  
Highway Bridges ◽  
Highway Bridge ◽  
Dead Load ◽  
Resistance Factors ◽  
Bridge Evaluation ◽  
Load And Resistance Factors ◽  
Practical Guidelines ◽  
New Criteria

Improvements to Clause 12 of CAN/CSA Standard S6-88 "Design of highway bridges" required the transformation of basic findings into a form suitable for use by evaluators. The number of dead load categories was reduced, and the rating equation was simplified. Rating factors calculated using the new criteria were checked against past practice. Practical guidelines for material grade identification and the evaluation of deteriorated components were developed. Three examples of the application of the provisions are included. Key words: calibration, codes (standards), evaluation, highway bridges, load and resistance factors, mean load method, safety.

A Human Factors Guide for Aviation Maintenance

1993 ◽  
Vol 37 (1) ◽  
pp. 30-33 ◽  
Author(s):  
James F. Parker
Keyword(s):  
Human Factors ◽  
Federal Aviation Administration ◽  
Job Design ◽  
User Preferences ◽  
Aviation Maintenance ◽  
Air Carrier ◽  
Safety Considerations ◽  
Maintenance Personnel ◽  
Economic Considerations ◽  
Selection Of

Safety considerations require that air carrier maintenance be of the highest quality and essentially error-free. Economic considerations require that maintenance activities be as efficient as possible. Success in meeting both safety and economic goals depends on the performance of those working in the aviation maintenance community. A human factors guide can be of value in supporting and enhancing the performance of aviation maintenance personnel. One end product of the Federal Aviation Administration (FAA) program on “Human Factors in Aviation Maintenance” is a guidebook presenting human factors information oriented specifically toward the air carrier maintenance workforce. The Human Factors Guide presents established principles of job design and work. Coverage is broad and includes a variety of topics considered important in determining maintenance effectiveness and in the control of maintenance error. The preparation of the Human Factors Guide was done in a manner to ensure that needs of users were addressed. Size and format were selected in terms of user preferences. Information obtained through a series of FAA-sponsored human factors meetings plus that gained from a survey of maintenance personnel guided both the selection of topics and the presentation of materials.

Production and Characterization of Biocoal for Coal-Fired Boilers

2014 ◽  
Author(s):  
Jaisen Mody ◽  
Roman Saveliev ◽  
Ezra Bar-Ziv ◽  
Miron Perelman
Keyword(s):  
Elevated Temperatures ◽  
Hybrid Poplar ◽  
Powder River Basin ◽  
Biomass Feedstock ◽  
Plant Site ◽  
Safety Considerations ◽  
Powder River Basin Coal ◽  
Economic Considerations ◽  
Firing Tests

As part of PGE-EBC-MTU collaboration of the testing program to fire up to 100% of biocoal in the 600 MW Boardman boiler we produced samples from the seven biomass feedstock: Arundo Donax (AD), wheat waste, corn waste, woody hybrid poplar, and bark from hybrid poplar, woody pine, and bark from pine. The idea was to produce a few thousand tons of biocoal from woody and bark poplar for a 100% firing tests and from the other types to produce a 1000 tons of biocoal from each material that will be co-fired up to 10% with Powder River Basin coal. Biocoal is produced by a torrefaction which is a thermal process carried out in absence of oxygen. We have produced biocoal samples from the above biomass feedstock in two pilot facilities, one in Israel and another in Michigan. The torrefaction process comprises the following steps: (1) shredding and soil separation, (2) drying, (3) torrefaction, and (4) compaction to produce biocoal briquettes. Biocoal briquettes are essential for logistics, safety, operational, and economic considerations. The briquettes must be durable, water resistant and can be pulverized in common coal mills. The briquettes that we produced did indeed conform to these properties. A real operational challenge was working with absence of oxygen which essential for the torrefaction process as well as for safety considerations because the entire process occurs at elevated temperatures which biocoal can burn. A 30,000 t/year torrefaction facility has been constructed at the Boardman Plant site to produce biocoal required for the firing tests.

Research on Assessment Methods of Load-Bearing Capacity of Existing Bridges

2010 ◽  
Vol 29-32 ◽  
pp. 1339-1343
Author(s):  
Guo Jun Liu ◽  
Yong Qing Yang ◽  
Fan Guo
Keyword(s):  
Bearing Capacity ◽  
Assessment Methods ◽  
People’S Republic Of China ◽  
Highway Bridge ◽  
People's Republic Of China ◽  
Bridge Inspection ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Republic Of China ◽  
Existing Bridges

This paper makes an in-depth research on Assessment Methods of Load-bearing Capacity of Highway Bridge (Ministry of Communications of The People’s Republic of China, 1988) and makes a conclusion on assessment methods. Combined with current bridge inspection technology, it points out the limitations and shortcomings of the methods, and proposes the direction of assessment of existing bridge load-bearing capacity.

Permit Vehicle Routing Using Reliability-Based Evaluation Procedures

2000 ◽  
Vol 1696 (1) ◽  
pp. 150-157 ◽  
Author(s):  
Joan R. Casas
Keyword(s):  
Vehicle Routing ◽  
Reliability Index ◽  
Traffic Load ◽  
Evaluation Procedure ◽  
Material Strength ◽  
Limit States ◽  
Critical Limit ◽  
Highway Network ◽  
Definition Of ◽  
Existing Bridges

The works carried out within the framework of the development of an automatic system for permit vehicle routing on the Spanish National Highway network are described. The focus is on the methodology adopted for analysis of the old existing bridges. Because information about bridge properties (geometry, material strength) and design live load is unknown, the evaluation procedure combines the information provided by in situ measurements and inspection with a reliability-based evaluation. The reliability index for the most critical limit states derived from the maximum effects due to actual traffic on the bridge is adopted as the comparison value to define a passage criterion. Any permit crossing the bridge alone or with traffic restrictions leading to a lower reliability index will not be allowed on the bridge. The actual traffic load is obtained from existing traffic records using a model of traffic flow. The method is applied to 10 bridges fully representative of the old and nondocumented bridges most often encountered on Spanish highways. The final result is definition of the standard permits as presented in Eurocode 1 that are allowed on the bridge. From the most unfavorable permit, a criterion is derived concerning the actual vehicle permits.

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