[7]01 | Introduction Bridge Aesthetics

Introduction

1.5 TerminologyA problem that can hamper meaningful debate between designers is consistency of terminology. The following annotatedphotographs set down the terminology used throughout these guidelines and should be understood by all involved in the bridgedesign process. (Definitions sourced from RTA Structural Drafting Manual and the RTA Road Design Guide).

Superstructure – that part of the structure whichsupports traffic and includes deck, slab and girders.

Transition pier – pier separatingdifferent superstructure types.

Substructure – that part of the structure, ie piers andabutments, which supports the superstructure andwhich transfers the structural load to the foundations.

Soffit – undersurface of thebridge superstructure.

Pile cap – A reinforced concrete mass cast aroundthe head of a group of piles to ensure they acttogether and distribute the load among them.

Pile – a slender member driven into or formed inthe ground to resist loads.

Safety / throw screen – protective fenceto deter the launching of objects fromthe bridge onto the highway below.

Pier – a part of the substructure whichsupports the superstructure at the end ofthe span and which transfers loads on thesuperstructure to the foundations.

Traffic barrier

Parapet – low protective concretewall at edge of bridge deck.

Railing – on top of parapet torestrict lateral movement of traffic.

Abutment – the part of the structure whichsupports the superstructure at its extremitiesand retains earthworks.

Spill through abutment – an abutment whichallows fill to form a slope into the end spanrather than retaining it with a face wall.

Deck – bridge floor directlycarrying traffic loads.

Span – the distance between pointsof support (eg piers, abutment).

Bridge Aesthetics Introduction | 01[8]

Introduction

Haunching – increase in the depth of a continuous beam at thepoint of support to withstand the increased moment ofbending on the beam.

Plank bridges – bridges which utilise a simple concrete plankand cross support construction system.

Planks – structural units.

Parapet – (outer face). Bearing – a component which supports part of the bridge and which transmitsforces from that part to another part of the structure whilst permitting angularand/or linear movement between parts.

Pedestrian barrier – a railingplaced on edges of bridgestructure for pedestrian safety.

Pier Cap / Headstock – a componentwhich transfers loads from thesuperstructure to the piers.

Beam / Girder – load bearingmember which supports the deck.

Safety Screen.