by Jerome a Paris
Sat Jan 28th, 2006 at 08:11:28 AM EST
This week's bridge blogging is interestingly situated at the interesection of engineering and politics.
Viaducto n°1, located in Venezuela on the highway between Caracas and its port and airport (see map below) deserves a post on its technical merits, as it was the first bridge on the planet built using precast prestressed concrete - and it was designed by the grand master of concrete, Eugène Freyssinet, with Jean Muller (both French engineers).
But the story today about that bridge is that it has been closed for fear that it might collapse, creating havoc in Caracas as it has cut off the city from both its airport and its port. With the World Social Forum taking in place in Caracas this week, the spotlight shines embarrassingly on this bridge.
Caracas is located a few kilometers away from the coast, on the other side of a pretty high mountain range. The highway from the city to the coast, where both the port and the airport are located, is vital for the city, as most imports (massive in a country that exports mostly oil) come on it.
(from this site)
Viaducto n°1 is located above a narrow gorge (now suspected to be a geological fault)
(from this site)
Whether because of geological movements, water infiltrations, or the consequences (on water or rock movement) or the uncontrolled construction of shantytowns around it, the bridge has begun to bend in the 80s. Muller suggested to replace it if the bend went over 50cm; it was 115cm early this year when a pile finally collapsed and the bridge finally closed.
As Le Monde reports, this closure could cost Venezuela as much as 1% of GDP growth this year, as trucks have the use the old mountain road (that now goes across shantytowns all the way), delays mount and prices go up. The half hour trip from the city to the airport takes 5 to 7 hours instead of the usual half-hour, and creates serious dirturbance of trade and life in the city.
It is a sad tale of procrastination and corruption in a country that has often been flush with oil money and has just as often wasted it. A contract to replace the bridge was signed in the 90s, and then cancelled (at high cost) for unclear reasons, and nothing has happened since then. Chavez is to blame for doing nothing in his 7 years in power, but his predecessors did little either. But infrastructure investment often appears as a waste of money, or at least as not obviously necessary spending in the short term, and gets postponed for the sake of political expediency.
This is a striking example, and one that the World Social Forum might want to ponder. Infrastructure investment is essential, and the main danger is not greedy companies or markets, it's bad governments.
Previous Bridge Blogging (by PeWi, unless indicated otherwise):
Thomas Viaduct (by Jerome a Paris (Dec. 28)
Calatrava's Twisted Mind (by DoDo (Dec. 1)
parallel lines(Oct. 27)
Galloping Gertie(Oct. 19)
animal bridges(Oct. 13)
transporter bridge in Middlesbrough (Sept. 29)
Lyonel Feininger edition(Sept. 22)
Activities on Brooklyn Bridge (Sept 15th)
Bridge of Alcántara (Sept 8th)
Tyne Swing Bridge(Sept 1st)
Muengstener Bruecke (Aug 25th)
Mostar Bridge (Aug 18th)