General technical definitions

Abutment — a substructure that supports the end of a superstructure and retains some or all of the bridge approach fill.

Arterial road — an arterial road as defined in the Transportation Association of Canada’s Geometric Design Guide for Canadian Roads.

Auxiliary component — a component of a structural system that does not constitute part of the intended load-sharing system. Auxiliary components include expansion joints, approach slabs, railings and barriers, and deck drains.

Average daily traffic — the total volume of traffic during a given time period, in whole days, greater than one day and less than one year, divided by the number of days in that time period.

Average daily truck traffic — the total volume of truck traffic during a given time period, in whole days, greater than one day and less than one year, divided by the number of days in that time period.

Ballast wall — that part of an abutment above the bearing seats used primarily to retain approach fill and to provide a support for an approach slab and expansion joint.

Barrier — a wall, railing, or fence that serves as a vehicular, pedestrian, bicycle, or combination barrier or as a noise or privacy barrier.

Barrier wall — a barrier that has no openings and is at least 800 mm high.

Bearing — a structural device that transmits loads while facilitating translation or rotation.

Bevelled end — a culvert end cut or formed to lie in a plane inclined to the vertical.

Bicycle barrier — a barrier for confining cyclists.

Box culvert — a closed-invert culvert with a monolithic rectangular or trapezoidal cross-section.

Bridge — a structure that provides a roadway or walkway for the passage of vehicles, pedestrians, or cyclists across an obstruction, gap, or facility and is greater than 3 m in span.

Clear recovery zone — a roadside area that can be safely used by errant vehicles, is immediately adjacent to the edge of a traffic lane, and is clear of hazards.

Coated reinforcement — steel reinforcement that is used in concrete and is coated with a protective coating complying with the requirements of Section 8.

Collapse — a major change in the geometry of a structure rendering it unfit for use.

Collector — a collector road as defined in the Transportation Association of Canada’s Geometric Design Guide for Canadian Roads.

Combination barrier — a barrier that serves as a vehicular barrier and as a pedestrian or bicycle barrier.

Component — a member of a structure requiring individual design consideration.

Crossfall — the transverse slope of a roadway, sidewalk, or deck surface.

Crown —

Crown of a bridge or culvert — the highest point on a curved soffit.

Crown of a roadway — the highest point of a cross-section, formed where opposite crossfalls meet.

Culvert — a structure that forms an opening through soil.

Curb — a raised surface beside a roadway, forming a vertical or nearly vertical face that delineates the roadway edge and in some cases also channels water.

Cut-off wall — a vertical wall attached to and extending below the end of a culvert or other structure.

Deck — a component of a bridge superstructure that carries and distributes wheel loads.

Deck joint — a structural discontinuity between two components, at least one of which is a deck component, that permits relative rotation or translation between the two.

Deck slab — a solid concrete slab that carries and distributes loads to supporting members.

Deck width — the horizontal distance, measured at deck level perpendicular to the direction of travel, from face to face of sidewalks or curbs (or barrier walls if there are no curbs).

Design — the process of planning, analyzing, proportioning, drawing, and writing specifications for the Construction of a structure.

Design lane — a longitudinal strip that is a fraction of the deck width, within which a truck or lane load is placed for the purpose of design or evaluation.

Design life — a period of time, specified by an Owner, during which a structure is intended to remain in service.

Divided highway — a highway with two or more roadways separated by medians or barriers.

Downpipe — a pipe for conveying water from a deck drain to the ground or to a storm sewer.

Downspout — a short pipe extending from a deck drain to below the bridge superstructure.

Drip groove — a groove formed in a surface and intended to cause water to drop off the surface rather than run along it.

Ductility — the ability to deform without failing after yielding.

Evaluation — the process of determining load-carrying capacity.

Expressway — an expressway as defined in the Transportation Association of Canada’s Geometric Design Guide for Canadian Roads.

Factored resistance — the resistance of a component, connection, foundation, or cross-section

calculated in accordance with the requirements and assumptions of this Code, including the application of appropriate resistance factors.

Failure — a state in which rupture, severe distortion or displacement, or loss of strength has occurred as a result of the load-carrying capacity of a component or connection having been exceeded.

Falsework — a temporary structure that is used to support another structure or a part thereof, usually during a particular Construction procedure or sequence.

Fascia — the surface that forms the lateral limit of a bridge.

Fatigue — the initiation or propagation of cracks caused by the repeated application of load.

Fatigue limit state — a limit state at which the effects of fatigue on the strength or condition of a structure are considered.

Floor beam — a transverse beam spanning between longitudinal girders, trusses, or arches.

Freeway — a freeway as defined in the Transportation Association of Canada’s Geometric Design Guide for Canadian Roads.

Gabion — a wire mesh basket that is filled with stone or broken rock or concrete and forms part of a larger unit used for slope stability, erosion control, or related purposes.

Girder — a longitudinal beam resting directly on the substructure.

Guiderail — a rail system along the edge of a roadway to delineate the roadway edge and to help

Hazard — any obstacle or other feature, e.g., an embankment, sideslope, or body of water deeper than 1 m, that, without protection, is likely to cause significant injury to the occupants of a vehicle striking it.

Headwall — a transverse wall at the end of a culvert.

Highway — a common and public thoroughfare, e.g., a road, street, avenue, parkway, driveway, square, place, bridge, culvert, viaduct, or trestle, designed and intended for, or used by the general public for, the passage of pedestrians, cyclists, animals, or vehicles.

Highway class — the class of highway determined in accordance with the volume of vehicular and truck traffic (see Clause 1.4.2.2).

Highway classification — a category of highway, i.e., freeway, arterial road, collector road, or local road, that is used in establishing criteria for the geometric design of bridges.

Interface shear — shear at and in the plane of an interface between

(a) dissimilar elements or materials, e.g., a deck slab and a beam, or a web and a flange; or (b) concrete cast at different times.

Lane — a traffic lane.

Limit states — those conditions beyond which a structure or component ceases to meet the criteria for which it was designed.

Load effect — any effect on or response of a structural component due to loads, forces, imposed deformations, or volumetric changes.

Load factor — a factor applied to loads to take into account variability of loads, lack of precision in analysis for load effects, and reduced probability of loads from different sources acting simultaneously.

Local road — a local road as defined in the Transportation Association of Canada’s Geometric Design Guide for Canadian Roads.

Longitudinal — the lengthwise direction. For bridges, this is normally the direction of traffic flow on the deck and of the main span. For culverts, it is normally the direction of the culvert axis.

Long-span bridge — a bridge with an individual span longer than 150 m.

Median — a raised or marked area that separates the roadways of a divided highway.

Member — an element or assembly of elements within a structure that performs an identifiable function and can require individual design consideration.

Multiple-load-path structure — a system of components in which the failure of any primary component or connection will not cause the structure to collapse.

Open-type abutment — an abutment in front of which is a slope extending downward from a point on the abutment face that is just below the superstructure.

Orthotropic deck — a deck that is orthogonally anisotropic. Normally this is a deck made of steel plate stiffened with open or closed steel ribs welded to the underside of the steel plate.

Pedestrian barrier — a barrier that is intended to confine pedestrians.

Pedestrian bridge — a bridge that provides a walkway primarily for the passage of pedestrians.

Pier — a substructure used to transfer superstructure loads from the spans it supports to the foundation.

Primary component — a component of a structural system that performs an essential role in load transfer and, on becoming ineffective, will substantially reduce the load-carrying capacity of the system or cause the collapse of a single-load-path structure.

Rehabilitation — a modification, alteration, or improvement of the condition of a structure or bridge subsystem that is designed to correct deficiencies in order to achieve a particular design life and live load level.

Reliability index or safety index — a numerical measure of the reliability of structures or components.

Resistance factor — a factor applied to the unfactored resistance of a component or material at the ultimate limit state to take into account the variability of material properties and dimensions, quality of work, type of failure, and uncertainty in the prediction of the resistance.

Return period — the average period in years between the occurrence of an event (e.g., a flood) and the next occurrence of an event of the same type.

Roadway — that part of a highway that is intended for or can be used by vehicles, including traffic lanes, shoulders, and other adjacent areas such as those provided for clearance, pedestrians, or bicycles, if these areas are not separated by a barrier, by a guiderail, or by a curb that is at least 150 mm high.

Secondary component — a component of a structural system that does not have an essential role in load transfer and whose removal from the structure would result in at most a minor redistribution of load effects to adjacent components.

Serviceability limit state — the limit state at which the effects of vibration, permanent deformation, and cracking on the usability or condition of a structure are considered.

Sidewalk — a pedestrian walkway located beside a roadway.

Single-load-path structure — a structure in which the failure of any primary component or connection will cause the structure to collapse.

Skew angle — the angle by which a bridge differs from a right-angled crossing. Normally, this is the angle between the longitudinal centreline of the bridge and a line perpendicular to the centreline of the bearings.

Span — the following distances:

(a) the horizontal distance between the centrelines of adjacent piers or abutments;

(b) where bearings are provided, the horizontal distance between bearing centrelines;

(c) for rigid frames, including box culverts, the clear opening width; and (d) a distance specified as a span in another Section of this Code.

Spread footing — a footing that transfers structure loads directly to the underlying soil, rock, or engineered fill.

Stress range — the algebraic difference between the maximum and minimum stress at the fatigue limit state where tension and compression are of opposite sign.

Stringer — a longitudinal element supporting the deck and spanning between floor beams.

Substructure — that part of a bridge, including abutments and piers, that supports the superstructure.

Superstructure — that part of a bridge that spans water, a roadway, a railway, or another obstruction and is supported by the substructure.

Temporary structure — a structure with a design life of less than five years.

Traffic lane — a part of a roadway designated for the movement of a single file of vehicles.

Transverse — in a plane that is perpendicular to the longitudinal direction.

Ultimate limit state — a limit state that involves failure (including rupture, fracture, overturning, sliding, and other instability).

Unfactored resistance — the resistance of a component or connection based on specified material properties and nominal dimensions and calculated in accordance with this Code.

Utilities — transmission and distribution lines, pipes, cables, and other associated equipment used for public services including, but not limited to, electric power transmission and distribution, lighting, heating, gas, oil, water, sewage, cable television, telephone, and telegraph facilities.

Vehicle — a motor vehicle, motor-assisted bicycle, trailer, traction engine, car, truck, farm tractor, road-building machine, or any device drawn or propelled by power other than that of the driver or operator, but not including the cars or engines of electric, diesel, or steam railways.

Yield strength — the specified or established minimum yield strength of a material.