Bridge Projects Abound Throughout African Continent
Bridge-building is booming in Africa. Key projects are being unveiled or are under construction to give the region vibrant, efficient and economic transport corridors and boost the incomplete integration of their associated economies.
Botswana and Zambia are hoping to commence construction of the delayed $259-million Kazungula Bridge over the Zambezi River, a critical strategy to improve Africa’s north-south corridor, which links mineral-rich Zambia and the Democratic Republic of the Congo to Botswana and the port of Durban in South Africa.
The project is expected to provide a solution to the transport constraints between Botswana and Zambia, where an estimated 100 cargo trucks on either side of the Zambezi River take up to two weeks at the border posts before crossing.
The 930-meter-long-bridge has three construction components: a railroad bridge, one-stop border-post facilities and 10 kilometers of access roads at the Kazungula border between Zambia and Botswana. The two-lane cable-stayed bridge will be tolled.
Financing was to come from the African Development Bank, the Japan International Cooperation Agency (JICA) and the governments of Zambia and Botswana. Although JICA had pledged $149.2 million of the project’s total cost, an equivalent of 57.5%, the Japanese have since withdrawn from the undertaking after debate over the contract award, approved by the Botswana and Zambia governments.
“[JICA has] pulled out, and we shall try to engage the African Development Bank to put in more resources. Then, we shall set the new groundbreaking date, which was supposed to have taken place this month,” Zambia Works and Supply Minister Yamfwa Mukanga stated in early August.
JICA's sudden withdrawal came after differences emerged over the technical evaluation of the project bids, culminating in both governments awarding the contract to South Korea’s Daewoo Engineering and Construction. Other bidders were Japan’s Shimizu, South Africa’s Stefanutti and China’s Major Bridge Engineering Corp.
Meanwhile, on the Ivory Coast, construction is progressing on Africa's first bridge over a lagoon, a project that is expected to be completed in the first quarter of next year.
The 1.9-km Henry Konan Bedie Toll Bridge, also known as the "third bridge" over the Abidjan Ebrie lagoon, is being constructed by the Socoprim consortium partners of Bouygues Travaux Publics, the Pan African Infrastructure Development Fund, Total CI, the Ivory Coast government and the National Investment Bank. The span will connect the new 6.6-km road between the residential district of Riviera to the industrial area of Marcory, both in the capital, Abidjan.
Socoprim spokesperson Neyrand Mariana says the $292-million precast-concrete bridge will consist of a 1,500-m-long viaduct divided into 30 spans of 50 m each as well as 400 m on a dike platform, which will protrude into the lagoon on the western shore of the Anoumabo channel. “It has been designed to be rather flat, to match the surroundings, and will rest on 31 pairs of foundation piles,” says Mariana. The 2-m-dia piles are constructed as deep as 90 m below the water and rise up to 5 m above the water.
Mariana says the bridge also will have “fully corrugated concrete” on its walls for decoration. “The boundary between the corrugated concrete and smooth concrete is marked by a curved line that draws a ripple scale.”
Meanwhile, in East Africa, Uganda and Tanzania are at different stages of bridge construction to help unclog the northern and central corridors, respectively. The northern corridor links the Indian Ocean port city of Mombasa in Kenya to neighboring Uganda, Rwanda, Burundi and the Democratic Republic of the Congo. Japan’s Zenitaka Corp. holds a construction contract, awarded by the Uganda Roads Authority (URA), for the $125-million New Jinja Bridge, nicknamed the "second Nile bridge."
The new, 525-m-long cable-stayed bridge has two 80-m-high, reinforced-concrete inverted-Y pylon towers, with substructures comprising 2-m-dia piles driven 20 m deep and socketed into sound rock with reinforced-concrete caps, according to a URA project brief. The superstructure will have a cellular concrete deck, supported by a central plane of multi-strand stay cables cascading from the inverted, Y-shaped concrete pylons.
Meanwhile, in Tanzania, completion of the country’s first cable-stayed bridge project has been delayed for six months to enable a Chinese consortium to address unforeseen challenges.
Begun in 2012, the 680-m-long cable-stayed bridge in the Temeke district now is expected to be completed in July 2015. Works Ministry Permanent Secretary Mussa Iyombe stated that China Railway Jiangchang Engineering Ltd. and China Major Bridge Engineering Co. encountered technical challenges in implementing the $136-million contract.
Iyombe noted that, during the installation of pillars to support the 27.5-m-wide bridge, it took an additional five months for the contractor to reach the required sand, at a depth of 84 m. The depth was anticipated to be 64 m.
“Due to the challenges the construction firm has faced, which I regard as genuine, the government has thought it wise to grant a six-month extension. This is a big project which thousands of people depend on, but it cannot materialize unless the pillars to support the bridge are installed,” Iyombe told Tanzania media.
The bridge and 2.5 km of approach roads were designed by Arab Consulting Engineers; 60% of fiunding is by the National Social Security Fund and 40% is by the government of Tanzania. Replacing the current Kivukoni ferry, the bridge will link the central business district of the capital, Dar es Salaam, to Kigamboni ward. The span will be operated as a toll bridge for 25 years.
In West Africa, Gambia and Senegal are putting the final touches on plans for the construction of the Trans-Gambia Bridge on the Gambia River. The crossing will ease traffic flow between the northern and southern parts of Gambia and Senegal. The 942-m-long cantilevered bridge with prestressed-concrete segments is expected to reduce travel time, boost trade and improve freight movement on the so-called Gambia Road Transport Corridor, an economic and strategic link connecting Gambia and Senegal to West Africa.
