Transportation Success/Failure Report

Each student was assigned a successful structure and a failed structure. We were to research and report different aspects of each structure and present them to the class. My assigned successful structure was the Millau Viaduct Bridge in Millau, France. My assigned failed structure was the L’Ambiance Plaza in Bridgeport, Connecticut.

Transportation Success: Millau Viaduct Bridge, France

•      Official Name: Le Viaduc de Millau

•      Location: Millau-Creissels, France. It stretches across the valley of the river Tarn. It is the chosen solution for taking the A75 Motorway.

•      Designers: Michel Virlogeux and Norman Foster

•      Design of Bridge: Cable-stayed. A cable-stayed bridge is one in which the weight of the deck is supported by a number of cables running directly to one or more towers.

•      Length: 1.55 miles

•      Height: 343 meters

•      Cost: $524 million

•      Construction on the bridge started October 10, 2001

•      The bridge opened to traffic on December 17, 2004

•      https://www.youtube.com/watch?v=PbQc5QgH4Ws

The YouTube video link will show you different angles of the bridge. It is a beautiful bridge and you will certainly enjoy it!

The bridge has received many awards for their outstanding structure and architecture. Below are the listed awards.

•      Chicago Athenaeum International Architecture Award

•      International Association for Bridge and Structural Engineering Outstanding Structure Award

•      The Building Exchange Award- Best Use of Architectural or Structural Design in a Regeneration Scheme, 2^nd Place.

•      Wallpaper Design Awards- Best New Public Building

•      ECCS European Award for Steel Structures

•      D&AD Gold Award

•      Travel & Leisure Design Award for Best Infrastructure

•      Singapore Construction Excellence Award- Civil Category

This bridge was a success because it eliminated traffic congestion, became a tourist attraction, and reduced travel time for drivers. Below are some pictures of the truly beautiful bridge.

Sources:

•      "Highest, Longest : Viaduct De Millau." Highest, Longest : The Viaduct De Millau. Web. 10 Mar. 2015. http://www.abelard.org/france/viaduct-de-millau.php

•      "Viaduc De Millau." YouTube. YouTube. Web. 10 Mar. 2015. https://www.youtube.com/watch?v=PbQc5QgH4Ws.

•      "Foster Partners." Millau Viaduct. Web. 10 Mar. 2015. http://www.fosterandpartners.com/projects/millau-viaduct/

Transportation Failure: L’Ambiance Plaza, Bridgeport, Connecticut

•      Official Name: L’Ambiance Plaza

•      Location: 210 Washington Avenue Bridgeport, Connecticut

•      Building Type: High-rise Building. A high-rise building is a building greater than 75 feet in height.

•      Structural Material: Composite Structure. Composite structure is a set of interconnected elements that collaborate at runtime to achieve a purpose.

•      Foundation System: Spread or Shallow Foundation. This is a type of foundation which transfers building loads to the earth very near the surface, rather than to a subsurface layer.

•      Architectural Style: Modernism

•      Main Usage: Residential

•      Height: 205.21 ft (estimate)

•      Width: 63 ft

•      The building collapsed during construction April 23, 1987

•      Killed 28 construction workers

•      There were 16 floors above ground

•      The building was constructed using the lift-slab method. The lift slab method is a method of constructing concrete buildings by casting the floor or roof slab on top of the previous slab then raising the slab up with hydraulic jacks.  

On the day of the collapse, at approximately 1:00 pm, workers were using a 12-ton horizontal jack between the two towers. Around 1:30 pm the ironworker was installing wedges in the west building, the worker heard the first loud bang, looked up to see the concrete “cracking like ice.” The floor slab above him collapsed onto the levels below. Within 2-10 seconds both towers collapsed completely.

The exact cause of the collapse remains unknown, however there are a few theory’s that have been made. They are as follows.

Ø  First Theory: Instability of the wedges supporting the 12^th floor and roof package. –Thornton Tomasetti Engineers

·        Wedges supporting the 12^th floor and roof package at the column were unstable and started the collapse. They state that a wedge supporting the package rolled out leaving the shearhead at this level supported by a single wedge. Additional movement of the slabs may have caused the remaining wedge to roll completely out, causing the buildings to collapse.

Ø  Second Theory: Jack rod and lifting nut slipped out due to a deformation of an overloaded steel angle welded to a shear head arm channel. –National Bureau of Standards

·        The NBS concluded in their investigation that the failure began at the buildings most heavily loaded column. The testing determined that when the shearhead and lifting angles were loaded with forces nearing 80 tons, they had a tendency to twist. During the lifting process the shearheads and lifting angles were loaded close to their maximum capacity. The angles deformed under the excess of force of the three 320 ton slabs, causing the jack rod and lifting nut to slip out of the angle and hit the column.

Ø  Third Theory: Global instability caused by lateral displacement. –Failure Analysis Associates

·        FaAA consultants focused on the response of lateral loading and overall torsional instability. In the absence of lateral loading the building would be completely stable. In the presence of lateral loading, the slab could become flexible.

Below are some pictures of the collapsed building.

Sources:

•      L'Ambiance Plaza, Bridgeport | 200341 | EMPORIS." L'Ambiance Plaza, Bridgeport | 200341 | EMPORIS. Web. 10 Mar. 2015. http://www.emporis.com/buildings/200341/l-ambiance-plaza-bridgeport-ct-usa

•      Web. 11 Mar. 2015. http://failures.wikispaces.com/L'Ambiance Plaza

•      Removable Forms (Cast-In-Place)." Cast-In Place/Removable Forms. Web. 11 Mar. 2015. <http://www.cement.org/think-harder-concrete-/homes/building-systems/cast-in-place>.