NHI Course 130055 - Day 1 Test
Questions and Correct Answers.
Deck - Answer Distributes the traffic loads to the superstructure.
Elements include wearing surface, bridge railing, sidewalk, median(?), & expansion joint.
Superstructure - Answer Spans a feature and distributes load to the supporting members.
Elements include girder, floor beam, stringer, truss, arch, spandrel columns, cables, cross girder,
and pin & hanger assemblies.
Substructure - Answer Transfers load from the superstructure to the foundation material.
Elements include columns, piles, walls, abutments, wing walls, and pier caps.
Flexible culvert - Answer Uses the surrounding earth to provide stiffness needed to resist
loads
(General) Culvert - Answer Elements: barrel (top, bottom, sides), head wall, and wing wall.
Function of Deck - Answer Support live load
Provides run off for precipitation
Function of Wearing Surface - Answer Protects top surface of deck
Provides smooth riding surface
Function of Deck Joints - Answer Allows for bridge expansion/contraction due to
temperature fluctuations
Allows for end rotation due to LL deflections
Smooth transition between bridge and approach
Protect underlying bearings & elements from moisture & debris
Function of Drainage - Answer Allows roadway precipitation to exit away from bridge
elements
Function of Roadway Appurtenances - Answer Minimize hazards for traffic on highways and
waterways (i.e. Signs to guide motorists/pedestrians, Lights to enable users to see at night or
regulate traffic, Barriers to prevent vehicles from falling off bridge and smoothly redirect errant
vehicles back to their paths)
, Function of Superstructure Elements - Answer Support deck and transfer loads from deck to
bearings and substructure (i.e. stringers transmit loads from deck to floorbeam and floorbeam
transmits loads to longitudinal girders, trusses, arches, etc.)
Function of Substructure Elements - Answer Support superstructure
Transmit loads from deck/super into ground
Function of Bearings - Answer Transmit loads from super to sub
Permit longitudinal expansion/contraction
Allow rotation caused by dead & live load deflection
Function of Culvert Elements - Answer Transmit flow of water from one side to the other
Headwalls stabilize culvert
Wingwalls stabilize roadway & guide water through/away from culvert
Components vs. Elements - Answer Components: Deck, Super, Sub
Elements: Bearings, Pier Cap, Stringers, Girders, etc.
2 Categories of Bridge Loading - Answer Permanent: dead loads
Transient: live loads and other changing loads
4 Types of Applied Forces - Answer Axial
Bending Moment
Shear Force
Torsional Force
Axial Force - Answer A force which acts through the longitudinal axis of a member
Bending Moment - Answer A combination of tension & compression forces developed when
an external load is applied transversely to a bridge member, causing it to bend
Positive bending = smiley face shape
Negative bending = frowning face shape
Shear Force - Answer The equal but opposite transverse forces which tend to slide one
section of a member past the adjacent section
Questions and Correct Answers.
Deck - Answer Distributes the traffic loads to the superstructure.
Elements include wearing surface, bridge railing, sidewalk, median(?), & expansion joint.
Superstructure - Answer Spans a feature and distributes load to the supporting members.
Elements include girder, floor beam, stringer, truss, arch, spandrel columns, cables, cross girder,
and pin & hanger assemblies.
Substructure - Answer Transfers load from the superstructure to the foundation material.
Elements include columns, piles, walls, abutments, wing walls, and pier caps.
Flexible culvert - Answer Uses the surrounding earth to provide stiffness needed to resist
loads
(General) Culvert - Answer Elements: barrel (top, bottom, sides), head wall, and wing wall.
Function of Deck - Answer Support live load
Provides run off for precipitation
Function of Wearing Surface - Answer Protects top surface of deck
Provides smooth riding surface
Function of Deck Joints - Answer Allows for bridge expansion/contraction due to
temperature fluctuations
Allows for end rotation due to LL deflections
Smooth transition between bridge and approach
Protect underlying bearings & elements from moisture & debris
Function of Drainage - Answer Allows roadway precipitation to exit away from bridge
elements
Function of Roadway Appurtenances - Answer Minimize hazards for traffic on highways and
waterways (i.e. Signs to guide motorists/pedestrians, Lights to enable users to see at night or
regulate traffic, Barriers to prevent vehicles from falling off bridge and smoothly redirect errant
vehicles back to their paths)
, Function of Superstructure Elements - Answer Support deck and transfer loads from deck to
bearings and substructure (i.e. stringers transmit loads from deck to floorbeam and floorbeam
transmits loads to longitudinal girders, trusses, arches, etc.)
Function of Substructure Elements - Answer Support superstructure
Transmit loads from deck/super into ground
Function of Bearings - Answer Transmit loads from super to sub
Permit longitudinal expansion/contraction
Allow rotation caused by dead & live load deflection
Function of Culvert Elements - Answer Transmit flow of water from one side to the other
Headwalls stabilize culvert
Wingwalls stabilize roadway & guide water through/away from culvert
Components vs. Elements - Answer Components: Deck, Super, Sub
Elements: Bearings, Pier Cap, Stringers, Girders, etc.
2 Categories of Bridge Loading - Answer Permanent: dead loads
Transient: live loads and other changing loads
4 Types of Applied Forces - Answer Axial
Bending Moment
Shear Force
Torsional Force
Axial Force - Answer A force which acts through the longitudinal axis of a member
Bending Moment - Answer A combination of tension & compression forces developed when
an external load is applied transversely to a bridge member, causing it to bend
Positive bending = smiley face shape
Negative bending = frowning face shape
Shear Force - Answer The equal but opposite transverse forces which tend to slide one
section of a member past the adjacent section
