| Name | Pont de Normandie |
|---|---|
| Who | |
| Owner | Chambre de Commerce et d'Industrie du Havre. Operated under concession from French State by SANEF subsidiary SAPN - Societe des Autoroutes Paris-Normandie |
| Design | Michel Virlogeux headed the team at SETRA - Service d'Etudes Techniques des Routes et Autoroutes with architects F Doyelle, C Lavigne |
| Design Evaluation | Six experts - Professors Lacroix, Schlaich and Walther and general inspectors Brignon, Huet and Mathieu. |
| Contractors | GIE du Pont de Normandie comprising: Bouygues, Campenon Bernard, Dumez, Grands Travaux de Marseille (GTM),
Quillery, SOGEA, Spie Batignolles CITRA. Steel Contractors: Eiffel Construction Metallique, Monberg and Thorsen with Cowi Consult. Foundation sub-contractors: Bilfinger Berger |
| Where | |
| Latitude | N 49 26' 08" |
| Longitude | E 0 16' 40 |
| When | 1989 to opening in 1995 |
| Why | Links Le Havre to Honfleur |
| Carries A29 autoroute | over River Seine |
| What | Read more..... |
| How to read the bridge | Read more..... |
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| What | |
|---|---|
| Overall type | Cable stayed 'fan' bridge |
| Width | 23.6 m with 4 lanes for traffic and 2 for pedestrians |
| Length | 2141.25 m |
| Spans | 856 m. with central steel section of 624 m and two outer concrete cantilevers of 116 m. Anchoring side spans (i.e. receiving back stay cables) at both ends are 96 m. and 6 spans at 43.5 m. The rest of the total (both ends) of 14 approach spans are 43.5 m. or less. |
| Height of tower | 202.74 m. above pile cap |
| Tower | Inverted Y shape |
| Materials | Tower: composite steel/concrete Deck: Central section: steel orthotropic box girder. Outer section concrete box. Cables: steel |
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| How to read the bridge | Read more about the book metaphor... |
|---|---|
| Chapter 1 | Suspension system |
| Paragraphs | Tower/Pylon: Each of the four legs, the vertical mast receiving the cables and the cross beams supporting the deck. Supporting cables: Each group of 23 pairs of cables either side of each pylon also incline laterally. |
| Sentences | Tower/Pylon: The legs are tapered concrete boxes of approx 10 m. by 5.473 m. Cables: Cables are 30-44 or 51 strands depending on location. |
| Words | Tower/Pylon: Cables anchored to pylon crest over about 60m. through a specially designed steel element cast into the concrete.
The cables are anchored between 2 vertical steel plates through inclined plates called 'shutter slats' - different for each pair of cables. Cables: Parallel strands 15 mm diameter and individually protected against corrosion. Wires are hot dipped galavanised and redrawn and voids between them filled with oil wax |
| Letters | Steel: Iron, carbon with other additives such as chromium etc Concrete: Cement, sand, aggregate and water Reinforced concrete: Concrete is strong in compression but weak in tension where it has to be reinforced with steel bars |
| Chapter 2 | Deck |
| Paragraphs |
Segments of the steel box girders and concrete box girders about 7.25 m.
long for appraoch spans and 2.6 m. long for main spans.
Their stream lined shape reduces wind forces.
The deck is connected rigidly to the pylons so that the main span and pylons act as a frame.
The weight of the last approach concrete span before the pyon is balanced by the concrete cantlever
part of the main span. The bridge is designed so that uplift forces occur only on the last pier before the
pylon. These forces are resisted by 4 vertical prestressing tendons anchored to the pier. |
| Sentences | Elements of the girders include two vertical webs for the concrete boxes.
The anchorages for the concrete boxes are below the deck and allow for transverse
prestressing of the deck at those points to distribute the cable forces into the deck.
The steel boxes comprise stiffened top and bottom steel plates, tapering webs and internal diapragms.
|
| Words | Individual steel plates and closed stiffeners welded to form the 'sentences'. Detailed elements of each of the anchorages including welded steel plates, tubes and pins. |
| Letters | Steel: Iron, carbon with other additives such as chromium etc Concrete: Cement, sand, aggregate and water Reinforced concrete: Concrete is strong in compression but weak in tension where it has to be reinforced with steel bars |
| Chapter 3 | Foundations |
| Paragraphs | Bearings: Piles: Bored piles |
| Sentences | Pile groups under each pier and each pylons. |
| Words | 14 individual bored piles are 2.1 m diameter and 54 m. deep. Access spans are on 4 piles 1.5 m diamter. Footings of legs of pylons connected by prestressed concrete transverse beam |
| Letters | |
| Grammar | Technically the bridge is a way of taking forces from up in the air down to the ground.
So imagine the flow of those forces through the structure.
Think of a truck standing on the bridge and how its weight is transmitted through the bridge to the ground. Read more about hanging bridges..... |
| Erection | The approach spans were launched incrementally up to the last pier before the pylon - using trapezoidal bearings (see References below for more details). The concrete parts of the side and main spans were erected by the 'balanced cantilver' method with each having specially designed tuned mass dampers to limit horizontal movements. The steel segments were lifted by from a barge, welded to the cantilever and both the stays and the corresponding back stays installed. Four sets of ropes connecting the stays help to dampen cable vibrations. |
| References | Virlogeux M, Normandie Bridge Design and Construction, Proc Instn Civ Engrs Structs & Bldgs, 1993, 99, Aug 281-302 |
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