Third Mainland closure

• Experts Canvass Bathymetric Surveys Of Facility
• Three Days Not Enough For Comprehensive Investigation – Structural Engineer
Far from promises by government that the closure of the Third Mainland Bridge would not result to hardship, commuters and motorists had hectic time adjusting to alternative routes.

For instance, a journey from Berger, which should take an hour at most, wasn’t about to end after seven hours, still at Adekunle Bus stop. This writer had to disembark the bus in order to catch an appointment at the Federal Palace hotel.

Commuters paid extra to reach different destinations after several hours on the road. For instance, those who went from Berger to Obalende/CMS
Paid N500, instead of N300.

Passengers were stranded at bus stops in places like Fadeyi, Yaba, Adekunle. Others had to trek for hours to their destinations.

Authorities had promised to deploy 200 FRSC personnel, 800 policemen and 500 Lagos Traffic Management for the three-day IMT investigation on the bridge and to ensure that traffic is well managed. Sure the men were on ground, but the challenge at hand went beyond their abilities and numbers.

The alternative routes announced were; the Ikorodu Road; Lagos-Abeokuta Expressway/Agege Motor Road, and the Gbagada Expressway.

Commuters heading to Fadeyi area of Lagos from Ketu or Ojota were advised to use the Ikorodu road. Those coming from Lagos, Abeokuta, Agege, Ogba and Ikeja were to make use of Oshodi via Mushin Ojuelegba to connect Carter Bridge into Island, while those from Ikorodu, Maryland were to make use of Funsho Williams Avenue, formerly, Western Avenue via Yaba to Oyingbo Eko Bridge into the Island.

Also, motorists from Okokomaiko, Festac, Oshodi-Apapa Expressway were to go through Ajegunle via Marina Bridge to Ijora to connect Carter Bridge to Apongbon into Lagos Island.

Alternatively, motorists from the Island would ply Eko and Carter to access the Mainland, while those in Lekki Ajah could use Epe axis, through Imota into Ikorodu.

The cost of the repairs as approved by government last May, was put at N18.874b. According to government, the Bridge opened about 30 years ago had experienced haphazard maintenance and repairs.

The once busy Third Mainland Bridge was deserted for investigations from Thursday night.

On the investigations being carried out on the bridge, a structural engineer, Dr. Adeleke Akintilo of IAA associates told The Guardian:
“I don’t know why they are shutting down the facility. What they do all the time is just on the surface. The third Mainland Bridge has two fundamental problems, which authorities are not addressing and that is why we keep having periodic shutdowns of the bridge.”

According to him, the deck, which motorists drive on has serious issues with the design, which has a cantilever structure that has been deflected.
“ The edges of the cantilever are already deflected and so what contractors do is to always put rubbers in-between the cantilevers and the substance would become so depressed. When you drive on the deck, you therefore notice vibrations. The second one, which is a general problem with all the bridges including Falomo is the dislocation of the foundation from the sandy formation.

“Our company did some repair work on the Independence Bridge. If you go to the boat club axis, there is a groin, which we designed and the reason for it is because of the dredging of sand and if you are dredging sand, it means that the (piles) foundation of the bridges will be affected. It’s like putting a nail within the wood and removing the wood. At the end, the wood would be exposed. That is why we have the dynamic effect on the bridge. If you come out of your car on top of the bridge, you feel as if it’s bouncing,” he said.

Akintilo also said there is need to carry out Bathymetric survey of the facility to know the depth of the level of sand below the water.
“If you find the level of the sand below the water, you would be able to know the extent of the piles that is floating and those wedging the sand. The deflection of the deck itself, you can’t re-correct it, except you do what is called supporting system. It like a building that is about to fall down and so you have to do appraisal.”

He emphasized that investigation being carried out must be comprehensive and must be made known to the public.

“People should be informed. If they are limiting the investigation to the deck, it means the investigation won’t be complete. If its comprehensive, it means they have to look at the foundation of the deck and if they combine the two, that could guarantee proper solution. However, the two investigations can’t be completed in three days.”

Speaking on expectations from the IMT investigation, a civil engineer at the University of Ibadan, Dr. Bamidele Fadahunsi said the result would reveal the level of stress capacity and the approach to adopt during the repair exercise.

“Now is the time to carry out in-depth investigation into the causes of riding discomfort on the bridge, especially at the joints, pier and ridge caps”

According to Dr. Festus Olutoge, a civil engineer, he said: “The closure will give unrestricted access to every part of the structure and enable experts to carry out detailed integrity tests through which parts that need intervention can be identified. It will also give them ideas of exact costs that would be required for the intervention.”