Caracas - The Viaduct Story

Caracas - The Story of our Viaduct (click any picture to get enlargement)

This story requires a short introduction: Venezuela is located on the top of South America, between Colombia & Guyana. Caracas, the capital, sits along the coast and is the largest city.

Caracas has over 4 million inhabitants & lots of high-rises.	The airport is quite nice and is located on the coast.	The Avila mountains separate the city from the coast.

*The Avila mountains are quite high & steep; thus it's not a easy task to get from Caracas to the airport or beaches.* *The drawing on the right (from the 1950's) shows the artist's depiction of the route they chose for a new highway.* *From Caracas the road would go along the steep side of a large valley, cross that valley, go thru a series of tunnels, and finally end up at the coast.* *The distance wasn't far... only 17km (10 miles) but the obstacles made for a difficult task, especially back in the 50s.*

The diagram on the right shows a little more detail of the plan, which included a large viaduct (bridge) and a couple of tunnels. The doted line shows the old road which linked Caracas to the coast. It was hilly, windy, slow and hard to maintain. The roadwork began ...

Then the viaduct plans were finalized. At that point in time it was one of the biggest engineering challenges in the world.

From the architectural plans, the construction began... ... it was quite a big project, even by today's standards!
		The final load-bearing structure is lifted into place.

After years of work, the result was an impressive highway... only 30 minutes to the coast!
	*Venezuela was rightfully proud of this engineering marvel.*


Fast-forward to today... *The highway system has had an ever-increasing amount of traffic using it, especially heavy trucks.* *The highway have also been poorly maintained and have fallen into disrepair.*


*Also, heavy yearly rains & the encroaching barrios have caused instability in the ground which supports the highway & viaduct.*


The viaduct began to show it's age, with a 'bulge' in the middle.

The engineers studied the problem and analyzed the geographical changes...		... and they came up with a plan to give the viaduct a facelift... by lifting one end and replacing the supporting structures... all to be done while the road was in use!


In 2005, the scaffolding went up and the repair work commenced. The ground around the area was coated to keep it from sliding.


The repair plan called for the existing support to be cut and 'air lifts' to be inserted. The lifts would then to filled with air, which would lift the bridge. New supports, being built on the sides, would then be take over the load when the air bags were deflated. The repairs started off suprisingly well.

*Work was proceeding according to plan... but someone forgot to inform Mother Nature.* *We had a torrential rainfall and, as you can see by the 'slippage' chart to the right, bad things happened to the ground.* *The chart shows the 'normal slippage' (in cm per year), which is pretty bad over the long term... but after this storm the whole hillside slide about 15 cm or more, which is over a foot!*

After the storm, cracks appeared in the roadway. It was obvious that sections of the viaduct had moved quite a bit!

*The 'bulge' was even more prominent... and then the worst news arose ... the engineers found their repair work in ruins.* *There was fear of collapse so the viaduct was closed to vehicles.*

Since the viaduct was such an essential link, many people crossed by foot ... hoping to catch a bus on the other side... but soon it was totally closed.

*At first there were many jokes circulated about the situation; the picture on the right is a good example... most were aiming to put the blame on the current government.* The government gave indications that all was under control... but soon it was apparent that getting to the coast would be a PAINFUL experience... that would have to be dealt with for a long time.


The old road, just to the right of the highway on the map above, was put back into operation. After a few days of accidents, terrible traffic, and frustrated people... limitations on types of traffic during certain times of the day were put into place. Bypasses were started & alternatives were developed:

*RED ROUTE: Old road... bad condition and many limitations, especially at night (trucks only); estimated time 3-4 hours in day.* *GREEN: Old cobblestone road over the Avila Mtns... 7000 feet! 4-wheel drive required, but quite scenic; estimate 1-2 stressful hours, but daytime only.* *BLUE: Lengthy night route bypassing steep mountains; estimated time 3-5 tiring hours & no safe places to stop for a rest.*

Now you know why you haven't seen many people from Caracas and we have seen few visitors. With all the hassles (2-5 hour trip) and costs ($150-$300) it just isn't practical to travel.

Animation of the expected collapse of the viaduct. It is rumored that casinos in Las Vegas are taking bets on when it will fall. On the other hand, this is what the new viaduct is supposed to look like... ... they must not think the old viaduct will fall, as it is still in the background!