The Msikaba Bridge Project continues to chalk up significant milesetones. The south pylon legs of the Msikaba Bridge were hydraulically jacked apart this month, marking an engineering milestone for the project. The 580-meter-long stay cable bridge, which will span the 198-meter-deep Msikaba Gorge, is being built in Lusikisiki in the Eastern Cape as part of the South Africa National Roads Agency‘s N2 Wild Coast project.
The CME joint venture (JV), a partnership of Concor Construction and MECSA Construction, is building the bridge. According to CME JV project director Laurence Savage, the jacking apart of the legs was opposed to bending at the bases of the cantilever legs and was done with two 150 t hydraulic jacks. According to Savage, these two legs make up the first 20 meters of the inverted Y-shaped pylon and are designed as free cantilevers with no lateral support.
The Msikaba Bridge construction process
According to Laurence Savage, the lateral support was put on the sixth lift of the pylon construction after 520 m3 of concrete had been poured to reach a height of 20 m. Two parallel sets of hydraulic jacks were constructed, and a jacking force of 1 750 kN was delivered to the two pylon legs to counteract the bending moment for the unsupported cantilever legs. To provide the needed force, the two 150 t hydraulic jacks were loaded to 90 t, producing 41 MPa of pressure. The jacking was done at 5 MPa intervals, and the structure’s deflections were monitored by dial gauges and surveying.
The punching force on the flat face of the pylon legs caused by the jack load was a critical issue, according to Savage. This also determined the size of the bearing plates attached to the interior of the legs, allowing for force dissipation across the suitable surface area. This prevented any structural damage caused by the loading of the concrete surface. Because the jacks only had a 50 mm stroke, the installations had to be precise – the 41 MPa pressure had to be attained before the jack ran out of stroke length.
The foundation plates were mounted on the pylon leg structure with 29 mm non-shrink grout, making the stroke length as short as possible. After the lateral support was properly oriented and placed, a grout biscuit was cast to fulfil two purposes. It did two things: first, it absorbed any tolerances in the installation after the original base plate installation, and second, it aided in the removal of the lateral support. Once the seventh lift was cast, and the legs were firmly linked together, breaking out the grout biscuit relieved strain in the lateral support. Savage stated that the temperature of the pylon structure and lateral support was measured to guarantee an average of 22 °C in order to prevent any unplanned variations in force owing to temperature fluctuations during the casting lift seven-building cycle.
To prevent temperature change movements and any associated changes in prop forces, the lateral support was covered in a 25 mm thick thermal blanket. A two-part mechanism was used to secure the lateral support: the locking ring on the hydraulic jack and the locking ring on the super-shore jack housing. The jacking preparation required three months of planning and study, while the setup took nine days. The actual jacking procedure took less than eight hours from start to finish.
Overview of the future structure
Once finished, four lanes of traffic and a pedestrian walkway on either side will pass beneath these legs at the bridge deck’s beginning and conclusion. The bridge will have two 128-meter-high pylons on each side of the gorge.
The bridge deck is supported by a network of 34 cable tendons extended across the pylons’ higher reaches. These cables are then routed from the tops of the pylons to anchor blocks situated 100 meters to the rear of the corresponding pylons. Each of the four anchor blocks is built of about 1 600 t of structural reinforced and mass concrete and extends 17 m into the ground – the equivalent of six storeys of a building.
The Msikaba Bridge Project which is expected to be South Africa’s longest cable-stayed bridge upon completion, will have a main span of 580m supported from a pair of 127m-tall pylons. The deck will be 194m metres above the valley floor, making it the third highest bridge in Africa, eclipsed only by the existing Bloukrans Bridge with a height of 216m and the Mtentu Bridge which, when completed, will be 223m high.
The bridge over the Msikaba Gorge near Lusikisiki in the Eastern Cape forms part of the N2 Wild Coast project being undertaken by the South African National Roads Agency Limited (Sanral).
The Msikaba bridge will require 43 000 m3 of concrete, 2 700 t of structural steel, 1 090 t of cables and 3 100 t of steel reinforcing. The balance of works contained in the contract includes construction of 1.5 km of approach roadworks on either side of the bridge.
Reported September 2018
South Africa to construct the second longest bridge in Africa
South Africa plans to construct a mega bridge dubbed Msikaba Bridge which will be the second longest bridge after Maputo-Catembe Bridge in Mozambique at a cost of a whooping US $5bn.
The South African National Roads Agency(Sanral) confirmed the reports and said the winning bid was a joint venture between South Africa’s Concor and Mota-Engil – a major international construction firm.
The Msikaba Bridge
The Msikaba Bridge, designed by Dissing and Weitling will have a tower-to- tower distance of 580 meters. Maputo-Catembe Bridge in Mozambique will be longer with a suspension span of 680 meters.
The cable-stayed bridge will also become the third highest bridge in Africa with a deck 194 meters high.This drop is exceeded only by the 216 meter high Bloukrans Bridge and the 223 meter high Mtentu Bridge, also located on the new N2 tollway bypass road.
Sanral added that the N2 Wild Coast road project will be a major job creator in an area with an extremely high unemployment rate. Sanral’s direct job creation forecast is 1.8 million man-days or 8,000 Full Time Equivalent (FTE) jobs over the construction period of four to five years.
The concrete structure will have a deck 22.8 meters wide with walkways on both edges and is expected to use some 2,700 tons of structural steel and 2,500 tons of cables. Construction is due to start in February 2019 and will last for 33 months, with initial planning proceedings set to begin in October 2018,according to Sanral.
Sanral awards Msikaba megabridge contract to Concor Mota-Engil JV
The South African National Roads Agency Limited (Sanral) has awarded the ConcorMota-Engil joint venture (JV) a contract to construct the second of two mega bridge as part of the N2 Wild Coast project.
The US $114.6m bridge project will be erected near Lusikisiki over the Msikaba gorge. The project is expected to commence its construction works in February 2019. However, once the project kicks start it is scheduled for completion in 33 months.
The contractor Concor Mota-Engil is a JV between civil engineering company known as Concor and international construction firm by the name Mota-Engil.
The bridge will comprise 28 000 m3 of concrete, 2 700 t of structural steel and 2 500 t of cables.
The height of the deck will be about 195 m above the valley floor, making it the third-highest bridge in Africa. The height of the piers will be 127m and the length of the main span will be 580 m, making it the longest main span constructed by cable-stay method in Africa.
Also read: SANRAL embarks on a public awareness initiative in the Eastern Cape
Meanwhile, construction on the nearby Mtentu river bridge started in January. The US $113.2m tender for that bridge was awarded to a JV between Aveng Grinaker-LTA and European construction firm Strabag in August 2018.
In line with the Government’s commitment to transform the public sector, The South African National Roads Agency Ltd (SANRAL) was established in April 1998 by an Act of Parliament as an independent statutory company operating along commercial lines and at arm’s length from Government. The purpose of the company, which is registered in terms of the Companies Act with the Minister of Transport as the sole shareholder is to maintain and develop South Africa’s expanding national road network (currently 21,403 km) and to manage assets with a depreciated replacement value of US $16.5m (excluding land).
Since the advent of democracy in South Africa, Government has sought to realign its public expenditure and the financing of public services to redress the imbalances of the past.
SANRAL harnesses more than 600 person years of core skills and experience in road development and management within a highly motivated, professional and passionate team of people operating out of its Tshwane (Pretoria) head office and four regional offices located in Tshwane (Pretoria), Cape Town, Pietermaritzburg and Port Elizabeth.
Reported in September 2021
Msikaba bridge construction project is now underway
Msikaba bridge construction project is now underway in the Eastern Cape province of South Africa. According to President Cyril Ramaphosa, the project is set to create 36 000 jobs and produce R4 billion in income for local companies.
The 580-meter-long Msikaba bridge construction project, which 127-meter-high pylons will support, is anticipated to be completed by the end of 2025 or early 2026.
Ramaphosa stated his satisfaction that the project was handled by a black South African contractor. The tender for the bridge’s construction was handed down in 2017 by the South African National Roads Agency (SANRAL).
The Msikaba bridge construction project, which will be built near the Eastern Cape’s rural town of Lusikisiki, is anticipated to create 36 000 jobs and contribute R4 billion to local businesses.
Already, R120 million has been spent in small, local businesses. President Cyril Ramaphosa announced this on Thursday during a visit to the bridge’s under-construction foundation in Lusikisiki.
The cable-stayed bridge should be completed by the end of 2025 or early 2026.
It was developed as part of the N2 Wild Coast Road project, which intended to increase investment and growth, establish new economic sectors, and strengthen its connectivity between rural and urban regions.
When addressing near the site, Ramaphosa stated that the project would generate between 21 000 and 28 000 indirect jobs during construction and 8 000 direct full-time jobs once completed.
The project has resulted in 28 000 indirect jobs being produced. Considering another 8 000 jobs generated during the project’s lifetime, a substantial number of jobs have been created overall.
The president also claimed that the salary cost would be R720 million. This is with both expert and unskilled workers already on board.
Work on the bridge’s foundation began in May of 2020.
According to Ramaphosa, the bulk of the workers would be trained on the job. Locals put up 62% of the 330-person crew on the bridge build. The principal contractor employed 156 workers, while local subcontractors hired 173.
According to Ramaphosa, 600 engineers and support staff will assure a fantastic conclusion during the building process.
Two 127-meter-tall pylons will support the 580-meter-long bridge.
The bridge’s deck, according to sources, would be 194 metres above the valley floor. This would make it Africa’s third-highest bridge, trailing only the current Bloukrans Bridge at 216 metres and the Mtentu Bridge, which will reach 223 metres when completed.
Reported July 2020
Construction of South Africa’s longest cable-stayed bridge in good progress
Construction of South Africa’s longest cable-stayed bridge ‘Msikaba bridge’ is in good progress. This is after construction works were temporarily halted due to the COVID-19 (Coronavirus) pandemic which led to a nationwide lockdown.
Workers on the project are strictly observing social distancing and all the regulations put in place to ensure the safety of workers; Concor Infrastructure and Mota Engil construction a joint venture tasked on the project confirmed.