Puente Mercosur

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Coordinates: 7 ° 40 ′ 29 "  N , 66 ° 9 ′ 11"  W.

Puente Mercosur
Tercer puente sobre el río Orinoco
BW
use Road bridge (later also railway bridge)
Crossing of Orinoco
construction Cable-stayed bridge
overall length 11.125 km
width 21 m
Number of openings 248
Longest span 360 m
Clear height 40 m
start of building 2006
planner Leonhardt, Andrä and Partner u. a.
location
Puente Mercosur (Venezuela)
Puente Mercosur

The Puente Mercosur is the third bridge under construction over the Orinoco ( Spanish Tercer puente sobre el río Orinoco ), as it is often called. It will cross the Orinoco near the small town of Cabruta in the state of Guárico and thereby connect the Caicara del Orinoco on the south bank and a large part of the state of Bolívar with the northern part of Venezuela . There is currently a not very efficient car ferry between Cabruta and Caicara .

Construction of the bridge began in 2006, with a construction period of around five years planned. Various problems, especially financial ones, led to a postponement of the completion date to 2016. Probably due to the bribery affair in which the Brazilian construction company and general contractor Odebrecht was involved in 2016, the deadline could not be met. A new date is currently (March 2017) not known. A newspaper reported that the Third Bridge over the Orinoco is now 20 times more expensive than the recently opened Beipanjiang Bridge in China, the tallest bridge in the world, built in just over three years.

The first bridge over the Orinoco downstream at Ciudad Bolivar standing Angostura Bridge is about 360 km away from the National Road 19, the orinoquia bridge at Ciudad Guiana is further 120 km downstream.

The project

The Puente Mercosur, known by Hugo Chávez, is intended to promote traffic within the framework of Mercosur , especially between Venezuela and Brazil , and to lead the national road 12 and possibly a railway line still to be built across the river.

As with the Puente Orinoquia, the Brazilian construction company Construtora Norberto Odebrecht , which has also been active in Venezuela for a long time, was commissioned as general contractor for the planning and construction of the project, Leonhardt, Andrä and Partner with the planning of the cable-stayed bridge and the Brazilian engineering office Figueiredo Ferraz commissioned the planning for all other bridge sections. As usual with such large projects, a number of other engineering offices were also involved.

At the construction site, the Orinoco is over 2 km wide at low tide; However, during the regular flood periods with up to 12 m higher water level, it floods the surrounding alluvial land up to a width of 15 km.

The project consists of a cable-stayed bridge as the central part of the 2,280 m long river bridge, to which 4020 m long foreland bridges and access viaducts connect in the north and 4825 m long in the south. This 11.125 km long bridge structure is connected in the north by an 11 km long road with the national road 12; in the south, a 3.25 km long road connects to the local part of the national road.

The bridge will have four lanes and the conditions for the later installation of a railway track in the lower part of the girder.

Odebrecht reported in March 2015 that the southern pylon was completed. The photos show that most of the bridge piers have also been created and parts of the superstructure are ready for later hanging or pushing in. According to the local media, this corresponds to a degree of completion of 67%.

Technical details

River bridge

The 840 m long cable-stayed bridge in the middle of the river has a central opening of 360 m and two side openings of 120 m each. It is supplemented on both sides by six bridge fields each with openings also 120 m wide, resulting in the total length of the river bridge of 2280 m.

The two 135.5 m high reinforced concrete pylons tower 82 m above the bridge deck. With their diamond shape they encompass the bridge deck, which rests on a strong crossbar made of prestressed concrete . They end in a vertical pylon head in which a prefabricated steel box with the anchoring for the stay cables is installed.

The stay cables are arranged in the longitudinal direction in the middle and as double cables. They are anchored to the pylon at intervals of 2 to 3 m and to the bridge deck at intervals of 10 m, with a 35 m window remaining between the pylon and the stay cables. The arrangement of the stay cables extends to the middle of the second side opening.

The pylons as well as all pillars of the bridge structure are founded on large bored piles that reach a depth of 90 m.

The bridge deck consists of three-span continuous girders with spans of 120 m and a steel, 9.8 m wide and 10.3 m high truss construction, in which the railway track can later be laid. The lower chord has a 5.9 m wide and 25 cm thick concrete slab on a continuous floor plate that is reinforced with longitudinal stiffeners and cross members. The upper chord consists of a 30 cm thick composite panel on a continuous, stiffened cover sheet, which cantilevers over the trusses 5.5 m on both sides and is therefore 21 m wide.

For construction, the bridge deck is delivered in 60 m long, largely prefabricated parts with push convoys on the river (which is not navigable all year round) and assembled into 360 m long and 9000 t units on the assembly areas set up in the extension of the bridge axis. These units are then pulled over the river in sections of 120 m each on the pillars and pylons until they protrude 120 m into the main opening. Then the outer stay cables are tensioned, the composite slabs are concreted and the remaining stay cables are tensioned after the concrete has hardened. Finally, the missing 120 m long and 2400 t weighing middle section is floated on pontoons, lifted to its final place with four strand jacks and connected to the bridge deck, the composite slabs are concreted on this section and the last stay cables are tensioned.

Approach bridges

The railway line is to be diverted from the bridge axis in lateral curves at both ends of the river bridge. This is why the approach bridges, each 940 m long, no longer have the large lattice girder, but a steel plate beam girder with transverse stiffening that is 19.2 m wide. On both sides of the river there will be 15 bridge fields with pillar spacing of 60 m and one field with 40 m.

Access viaducts

In the areas leading to the dry areas, viaducts with field widths of 35 m will be built - also on pile foundations : in the north 88 fields with a total length of 3080 m and in the south 111 fields with a total length of 3885 m. In each field 5 parallel, prefabricated, U-shaped prestressed concrete girders are suspended, onto which the 19.20 m wide reinforced concrete deck is attached.

Web links

Individual evidence

  1. ↑ Tercer puente sobre el Orinoco it 20 veces más caro que el más alto del mundo. Article of March 19, 2017 on El Estímulo
  2. ↑ a b Tercer Puente sobre el Río Orinoco: Odebrecht finaliza las obras de la torre sur. Note dated March 16, 2015 on the Odebrecht website
  3. ↑ a b Wolfgang Eilzer, Karl Humpf, Michael Müller, Michael Moslener: Puente Mercosur - The third bridge over the Orinoco In: Stahlbau-Nachrichten 3-2014, pp. 43–46
  4. ↑ III Ponte Rodoferroviária sobre o Rio Orinoco On the website of the Figueiredo Ferraz engineering office
  5. ↑ A list of the most important participants can be found at the end of the PDF file III Ponte Rodoferroviária sobre o Rio Orinoco (see web links)
  6. ↑ Avanza construcción del III puente sobre el Río Orinoco (+ photos) Article of October 26, 2013 on Correo del Orinoco
  7. ↑ Culmina construcción de torre principal del tercer puente del Río Orinoco: el avance es de 67%. Article dated December 13, 2014 on Noticias 24 Venezuela
  8. ↑ The information in this section is based on the article by Wolfgang Eilzer, Karl Humpf, Michael Müller, Michael Moslener: Puente Mercosur - The third bridge over the Orinoco In: Stahlbau-Nachrichten 3-2014, pp. 43–46
  9. ↑ a b The information in this section is based on the PDF file published by Odebrecht III Ponte Rodoferroviária sobre o Rio Orinoco (PDF 3.37 MB)