Third Mainland Bridge
Just about four months after Messrs Borini and Company Limited, an Italian construction firm, completed a major repair work on Africa’s longest bridge, the Third Mainland Bridge, an independent structural integrity examination conducted last December revealed grave conditions of this strategic infrastructure, but the Minister of Works, Mr. Mike Onolememen debunked it as mere rumour, Gboyega Akinsanmi writes
After a few months of road rehabilitation on the Third Mainland Bridge last year, the bridge was opened to the admiration of Lagosians who applauded the Federal Government for taking the initiative to save lives. But now, a new report on the state of Third Mainland Bridge suggests otherwise. The report simply described the bridge as “an accident waiting to happen unless the degradation is urgently arrested.” And this sparked some apprehension, especially among the regular users of this infrastructure, which is the longest of its kind on the continent of Africa.
But critics say the new report is mind-bending and revealing. They say It is indeed unbelievable because its content is not in any way different from the content of the early report, which compelled the Federal Government to contract the repair of the bridge to Messrs Boroni Prono & Company Limited in 2012.
The repair work gulped a whopping sum of N1.055 billion and lasted four months, from July 7 to November 6.
According to the new report made available to THISDAY, about 1,318 foundation piles of the bridge “have suffered concrete degradation and appreciable loss of concrete materials”.
The findings of the underwater investigation by a concrete engineering firm, NSD Divers & Engineers indeed revealed so much.
The report of the investigation with photographic evidence conducted in collaboration with the Head of the Yonsei Concrete Structural Engineering Laboratory, Prof. J.H.J. Kim, has been forwarded to the Senate by Olugbenga Ashafa , a Senator representing Lagos East at the National Assembly.
The report also gave details of the method used in the conduct of the underwater inspections, which it said, were carried out with the latest tools available in the industry. The report said the residual thickness of the caissons checked, integrity of the reinforced concrete in-fill tested and corrosion of the embedded steel reinforcements thoroughly investigated and inspected between December 3 and 4, 2012.
The report further said the scope of the inspection covered soil erosion and buildup at the pile or lagoon bed interfaces, all of which “shows grave conditions of concrete degradation and concrete materials in about 1,318 piles. There was also concrete degradation and appreciable loss of concrete material in 46 foundation piles. There was extensive reinforcement bars deterioration in about eight piles.”
In the report: “There was extensive damage of confining steel caissons and progressive concrete spalling in 24 piles. There was also progressive caisson deterioration in 1,318 foundation piles. The bridge is an accident waiting to happen unless the degradations are urgently arrested to avert grave situations on Africa’s longest bridge.”
To be sure, the photographs presented as proofs of the deterioration of the Third Mainland Bridge show corroding steel reinforcement and concrete degradation at Pile 2 of Coping No. 46; the barnacle Infested and damaged cassion of the piles on Coping No. 6; spread of marine growths on infill concrete of coping No. 18; complete degradation of infill concrete of pile No 1 of Coping No 55 and progressive deterioration of foundation pile at Coping No 55.
More of the photographs show exposed reinforcement bars in the concrete infill of coping No 19; extensive deterioration and a hollow space in the steel cassion of coping No. 19; measurement of the depth of depletion of concrete infill (100mm) as Coping No. 55; deteriorated concrete infill and corroding steel reinforcement bar on coping No 55; and cavity in the concrete infill through a hole in the steel cassion of coping No. 64.
Other photographs show deteriorating concrete infill section after the steel cassion has depleted on Coping No. 64; interconnected cavities in the concrete infill of Coping No. 68; and a deeper cavity perforated through the steel cassion of Coping No 68.
All these proofs were the reasons Senator Ashafa co-sponsored a motion with 54 other lawmakers that recently requested that a fresh structural integrity test should be conducted to determine the strength of the bridge.
The motion asked the Federal Government to conduct an investigation “to ascertain the actual state of the bridge.
Yes, before now, Governor Babatunde Fashola (SAN) had directed the state’s Commissioner for Transportation, Mr. Kayode Opeifa to write the Federal Government on the grave conditions of the bridge notwithstanding a major repair work recently carried out on the infrastructure.
But the Federal Government termed the new outcry over the state of the bridge a party politics. In a report it issued after Ashafa’s motion, the federal government simply dismissed with a wave of hand the outcry over the state of the Third Mainland Bridge, which is adjudged the busiest in West Africa, saying that the bridge “is not going to collapse soon.”
Director of Highway Design in the Federal Ministry of Works, Mr. Aniete Effiong explained the steps the Federal Government had taken to ensure that the bridge is protected and kept in an acceptable service state. “It is a very important infrastructure and forms a vital artery of the network of federal highways in Lagos metropolis. The bridge is 11.8 kilometres and was constructed in two sections,” he says.
According to the director, the first section, from Lagos Island to Ebute Metta (Adeniji Adele Interchange–Adekunle Interchange), which has a box girder arrangement cantilevered from the pier to the mid-span, was completed in 1979 by PGH, a consortium made up of Messrs Borini Prono, Messrs Girola and Messrs Hiconi. The second section from Ebute Metta to Oworonshoki, which was later completed in 1990 by Messrs Julius Berger Nigeria Plc, is a multi-span structure.
But Ashafa insists there must be further investigation. He expressed dismay at an attempt to politicise the issue. He said he simply drew attention of the lawmakers to the new report and demanded for a further investigation to determine the bridge’s structural integrity. He maintained, it arose from incessant complaints of shifting and unusual vibrations on the bridge by commuters plying the bridge for quite some time, even after the Federal Government had carried out repair works on the bridge.
He said the report, an outcome of underwater surveys, showed that the underwater metal casing, housing the concrete piles on which the bridge stands, “have rusted and accounts for the vibration experience in some portions of the bridge. This led to the closure of the bridge for repairs between July 7 and October 30, 2012.”
He said, last December, the consultant made a research into the reasons for continued vibration of the bridge as complaint by the commuters who ply it. He thereafter conducted underwater examination of the structures holding the bridge and reported damages to the structure which puts lives at risk.
Citing what led to the collapse of the bridge over Mississippi River at Minneapolis in the United States on August 1, 2007 and Sungsu Bridge in South Korea on October 21, 1994, Ashafa said the bridge’s collapse could lead “to a huge loss of lives and worsen the traffic situation in Lagos.”
For now, the Federal Government has debunked fears of the collapse of Third Mainland Bridge and has reiterated its commitment to taking proactive measures to ensure that the bridge is kept in an acceptable service condition.
Minister of Works, Mike Onolememen made the disclosure in Abuja while reacting to media reports on the alleged near-collapse of the bridge.
He said the speculations are based on mere perceptions, as they have not been justified by any civil engineering test, adding that the ministry is progressing in ensuring routine maintenance.
He disclosed that the defects in the eight expansion joints of the bridge were spotted, repaired and replaced since last year.
Onolememen admitted that serious steel casing corrosion is noticeable on the bridge but maintained that the steel casing has no structural correlation to the pile-bearing capacity, as it serves only as form works to the piles.
He advised the general public to ignore the alarms, as the Third Mainland Bridge is not in any way defective. He said he himself still drove on the bridge twice last week on different days, and asked “Lagosians to continue using the bridge.”
He maintained that the structural integrity of the bridge was not in any doubt, considering that further tests by reputable engineering companies have confirmed the adequacy of pile concrete quality.
“Based on their advice, the ministry is ensuring continuous routine maintenance works,” he added.
Also, the Council for the Registration of Engineering in Nigeria (COREN) shared a different view from the consultant that conducted an independent investigation on the bridge. The council’s Chief Inspector (Ikeja Inspectorate), Mr. Ayo Fanimokun faulted the consultant’s report on the ground that he did not inform the council of his intention and mission during the period he came into the country for the inspection.
Fanimokun explained that it was a global best practice for any expatriate consultant to declare its mission to the engineering regulatory institution in a country he is invited to do certain jobs. “It is not done anywhere in the world. The consultant ought to have notified COREN of his intention and mission in Nigeria so that we too can supervise and get a copy of such report. This is the process globally,” He stated.
Likewise, President of the Nigerian Institution of Civil Engineers (NICE), Mr. Amos Omopeloye shared the same view. He also assured Nigerians of the bridge’s structural integrity contrary to the consultant’s report. He said, “ If we say the bridge is functioning and it happens otherwise, we are indicting ourselves. Those who said the bridge is not safe are not sure of their findings. They are not professionals.
“We have our professional integrity to protect. There is nothing wrong with the bridge. We were there for two weeks carrying out tests and inspection. Nigerian engineers are capable, we cannot lie to the public. We are not the one that wants to kill the people. If the consultant wants to practise in Nigeria, he must go through a process and that process is to register with COREN.”
On Monday, THISDAY contacted Kim, the South Korean consultant, by email to obtain his position on the matter, but at the press time, Kim has not replied the mail. The email to Kim simply sought to know details of how he carried out the investigation; whether he informed the country’s engineering regulatory body about his intention; and how he arrived at his findings among others.