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Questions and Answers
What is the definition of a bridge according to AASHTO LRFD Bridge Design Specifications?
What is the definition of a bridge according to AASHTO LRFD Bridge Design Specifications?
What is the design life of a bridge according to AASHTO LRFD Bridge Design Specifications?
What is the design life of a bridge according to AASHTO LRFD Bridge Design Specifications?
What is the purpose of an evaluation according to AASHTO LRFD Bridge Design Specifications?
What is the purpose of an evaluation according to AASHTO LRFD Bridge Design Specifications?
What is the property of a component or connection that allows inelastic response according to AASHTO LRFD Bridge Design Specifications?
What is the property of a component or connection that allows inelastic response according to AASHTO LRFD Bridge Design Specifications?
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Who is responsible for the design of a bridge according to AASHTO LRFD Bridge Design Specifications?
Who is responsible for the design of a bridge according to AASHTO LRFD Bridge Design Specifications?
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What type of events have return periods in excess of the design life of a bridge according to AASHTO LRFD Bridge Design Specifications?
What type of events have return periods in excess of the design life of a bridge according to AASHTO LRFD Bridge Design Specifications?
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What is the nominal resistance of a component, as indicated by the contract documents and permissible stresses?
What is the nominal resistance of a component, as indicated by the contract documents and permissible stresses?
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What is the Load and Resistance Factor Design (LRFD) methodology?
What is the Load and Resistance Factor Design (LRFD) methodology?
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What is a movable bridge?
What is a movable bridge?
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What is the purpose of a load modifier?
What is the purpose of a load modifier?
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What is a multiple-load-path structure?
What is a multiple-load-path structure?
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What is the service life of a bridge?
What is the service life of a bridge?
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Study Notes
AASHTO LRFD Bridge Design Specifications
- AASHTO LRFD Bridge Design Specifications are published by the American Association of State Highway and Transportation Officials.
- The 4th Edition was published in 2007 and uses SI units.
Definitions
- Bridge: a structure with an opening of at least 6100 mm that forms part of a highway or is located over or under a highway.
- Collapse: a major change in the geometry of the bridge rendering it unfit for use.
- Component: a discrete element of the bridge or a combination of elements requiring individual design consideration.
- Design: the proportioning and detailing of the components and connections of a bridge.
- Design Life: the period of time on which the statistical derivation of transient loads is based, which is 75 years for these specifications.
Key Concepts
- Ductility: the property of a component or connection that allows inelastic response.
- Engineer: the person responsible for the design of the bridge and/or review of design-related field submittals.
- Evaluation: the determination of the load-carrying capacity of an existing bridge.
- Extreme Event Limit States: limit states relating to events such as earthquakes, ice load, and vehicle and vessel collision, with return periods in excess of the design life of the bridge.
- Factored Load: the nominal loads multiplied by the appropriate load factors specified for the load combination under consideration.
- Factored Resistance: the nominal resistance multiplied by a resistance factor.
Bridge Types
- Fixed Bridge: a bridge with a fixed vehicular or navigational clearance.
- Movable Bridge: a bridge with a variable vehicular or navigational clearance.
- Multiple-Load-Path Structure: a structure capable of supporting the specified loads following loss of a main load-carrying component or connection.
Load and Resistance Factor Design (LRFD)
- LRFD: a reliability-based design methodology in which force effects caused by factored loads are not permitted to exceed the factored resistance of the components.
- Load Factor: a statistically-based multiplier applied to force effects accounting primarily for the variability of loads, the lack of accuracy in analysis, and the probability of simultaneous occurrence of different loads.
- Load Modifier: a factor accounting for ductility, redundancy, and the operational importance of the bridge.
Other Concepts
- Model: an idealization of a structure for the purpose of analysis.
- Owner: the person or agency having jurisdiction over the bridge.
- Regular Service: the condition excluding the presence of special permit vehicles, wind exceeding 90 km/h, and extreme events, including scour.
- Rehabilitation: a process in which the resistance of the bridge is either restored or increased.
- Resistance Factor: a statistically-based multiplier applied to nominal resistance accounting primarily for variability of material properties, structural dimensions, and workmanship, and uncertainty in the prediction of resistance.
- Service Life: the period of time that the bridge is expected to be in operation.
- Service Limit States: limit states relating to stress, deformation, and cracking under regular operating conditions.
- Strength Limit States: limit states relating to the maximum load-carrying capacity of the bridge.
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Description
Test your knowledge of the American Association of State Highway and Transportation Officials' (AASHTO) LRFD Bridge Design Specifications, 4th Edition, 2007. This quiz covers the definitions and concepts outlined in the specifications, focusing on bridge design and construction. Get ready to put your skills to the test!