Padma Bridge: How Bangladesh defied the odds to achieve a technical masterstroke

The dream of connecting Bangladesh's heartland to the southwestern region by bridging the mighty Padma River had long seemed elusive but the Padma Multipurpose Bridge is about to propel that ambition to reality.

The mega structure, set to open on Jun 25, represents a landmark achievement for Bangladesh, not least because it was built with the country's own resources after a much-publicised standoff between the Awami League government and the World Bank over funding the ambitious project.

But the bridge is also a feat of engineering in light of the myriad technical challenges that had to be overcome and lays down a benchmark for other infrastructure projects in the country. In the words of Chinese Ambassador to Bangladesh Li Jiming, the project involved "13 technologies which have never been used in the world" and was "full of experiments that nobody had ever done before".

As the clock ticks down to its inauguration, Shamim Z Basunia, head of the Padma Bridge project's expert panel, looked back on the six years it took to construct arguably the country's most significant structure in an exclusive interview with bdnews24.com.

Describing the Padma as an “unusual” river due to its geological features, he believes the fact that Bangladesh was able to fund and manage such a "difficult" project by itself bodes well for future infrastructure ventures.

But the journey has been beset with numerous hurdles. The fate of the Padma Bridge was thrown into doubt in June 2012 when the World Bank cancelled a $1.2 billion credit due to alleged corruption among government officials connected to the project.

A month later, Prime Minister Sheikh Hasina famously announced that Bangladesh would mobilise its own funds to pull off the project.

Engineers of Padma Bridge Rail Link Project taking a photo after the last span was installed on Tuesday, May 4, 2021. Photo: Mahmud Zaman Ovi

At the time, Hasina was keen to know if the construction could be initiated by March or April 2013, Basunia recalled.

“I was a bit scared and said I’d be able to do it if my teacher Prof Jamilur Reza Choudhury was involved [in the project]. She then rang him up and he said he could do it. I looked at him and he said everything was ready. I realised then that we only lacked the funds.”

The construction work was divided into five parts - the main bridge, river training, the Zajira approach road and selected bridge end facilities, the Mawa approach road and selected bridge end facilities, and setting up service areas on either bank.

Hasina flagged off work on the main bridge and river training in December 2015.

A former professor of BUET, Basunia said a test of ability and courage emerged for Bangladesh as it managed the project on its own.

“River training was a huge challenge. China’s Sinohydro Corporation carried it out. Many allegations popped up against them. But we looked them up and found their global river training experience to be decent. We gave them the job after they came out on top of three companies who bid for it.”

He said it will take one more year to complete the river training work at the risky Mawa docks.

Meanwhile, coastal construction along a 14 km-area on both sides of the Padma River has been completed. Geo bags weighing 800 kg each are being used to protect the bridge.

The government spent Tk 900 billion on river training, the highest expenditure on such work globally, according to Basunia.

Enlarging on the characteristics of the Padma, he explained that heavy rainfall intensifies the river currents and causes sediments to rise higher up in comparison to other rivers. Therefore, the bridge stands 70 feet above the water surface to allow transports to move without any issues.

“In a year, sediment deposits in the river scale heights of 25-30 feet. How is a boat supposed to move then? We’ve taken steps to tackle that issue.”

As many as 40 piers have been set up under the bridge, with two additional ones on each bank. Under each pier, steel piles with a three-metre radius have been driven 122 metres deep into the river bed.

Speaking ahead of the inauguration of the 'dream bridge', Chinese Ambassador Li Jiming said each pile required 20,000-30,000 blows on average to be driven in place. Five state-of-the-art hydraulic pile hammers, including the largest one in the world, were deployed, according to him.

The full 6.15-km stretch of the Padma Bridge came into view after engineers installed the 41st and final span of the structure on Thursday, Dec 10, 2020. Photo: Mostafigur Rahman

Basunia says the piles used in the project are the thickest and deepest in the world.

“It was a huge challenge for us and took over a year to complete.”

Engineers faced issues setting piles in the Mawa end, where the water is deeper. A few changes had to be made to the design in order to deal with the issue, according to Basunia.

“From a technical standpoint, the biggest challenge was posed by the poor quality of soil in one location. It was weak and had clay. We had to either avoid the layer of clay or leave the piles three metres above it. For the latter, we needed more piles.

“We then contemplated drilling seven piles instead of six into the surface and met with several specialists, including two soil experts from Japan. Later, we went for seven piles in 22 piers.

“After setting the piles, an X-ray was needed to confirm whether there were any cracks in the welding. We did that and the quality was tested again. There was no room for error.”

The two-storey bridge is made of concrete and steel. Aicom, Spec International, ACE Consultants Ltd and North West Consultations Ltd designed it.

Basunia said that the Chinese company suggested working with steel carved into smaller plates. Everything would be done in China, including quality control.

“We went to Wuhan at the time. We were satisfied with the plates and their quality. After returning, we asked an engineer to go there. He’d stay there and oversee things there.

“The piles’ plates were the first to arrive from there. They had a 10 feet diameter. These pipes were bent and welded. The welding was mostly done by Bangladeshis but Chinese people worked on it as well.”

More than 500 Bangladeshis were among the 4,000 engineers and technicians working on the project.

As part of efforts to ensure the highest standard for all equipment of the bridge, the bridge stands on the state-of-the-art pendulum bearings, according to Basunia.

“We went to China to assess its quality. We [simulated] an earthquake after putting the capacity load on it. It moved quite a bit before returning to position. After the bearings were detached, no cracks or even scratches appeared. This was done three times.”

“Yet, we sent it to the United States for further testing.”

Basunia said such bearings have never been used before anywhere and they can withstand 9.0 magnitude earthquakes. The Padma Bridge bearings can sustain more than 10,000 tonnes, exceeding the limit of any other structure in the world.

Pointing to several instances of ferries ramming into the piers of the bridge, he said these were no cause for concern due to the quality of the construction materials.

But he questioned how ferries collided into the piers.

“There is a clear 400-feet gap between each pair of piers. The width of a ferry is about 50 feet. How can a collision still occur? If a ferry had rammed into the middle of a pier rather than on a side, it would’ve capsized. A pier is 10 times stronger than a ferry. Ferries can’t damage a pier.”

The majestic 6.15-kilometre long Padma Bridge stands out against the horizon in all its grandeur It's difficult to capture the gigantic infrastructure in one frame. Photo: Mahmud Zaman Ovi

QUALITY MATERIALS

The construction of the massive structure required almost 300,000 tonnes of rods, 250,000 tonnes of cement, 350,000 tonnes of sand, and almost 2,100 tonnes of bitumen. These were mostly procured from local sources.

Basunia claimed the cement and rod manufactured in Bangladesh are 'world-class'. “The local companies are working very smartly. They are quite capable. They only lack the proper equipment.”

Many equipment, including 192 girders brought from Luxemburg, were put to use in the erosion that occurred in 2020.

Basunia said the government utilised manpower, machines and equipment from more than 20 countries in constructing the bridge, which also required a 3,500-tonne hammer, the largest in the world, and a crane weighing 4,500 tonnes.

Stones for the concrete used in the bridge were from Bangladesh, India, Bhutan and the United Arab Emirates.

A large consignment of rods was hauled in from China while aluminium was shipped from the UAE and the United Kingdom.

A view of the Padma Bridge taken from the river on Monday, June 14, 2021. According to information from the Bridges Division, construction work on the bridge was 93 percent complete as of Jun 1. The government hopes to allow traffic across the bridge from next year if things proceed as planned. Photo: Mostafigur Rahman

MAINTENANCE

The road on the bridge is ready but the railway is still under construction. The Padma Multipurpose Bridge will be subject to regular maintenance once all the work is complete next year.

Basunia stressed the need to observe every minute details to sustain the bridge. “We’ve taken all the steps to regularly maintain the bridge. Everything will be tracked, even the rust that gathers somewhere on the steel. Details of when each component of the bridge should undergo maintenance has been laid out."

“The prime minister has already said that a separate body will be created for the bridge's maintenance. She has already set up two police stations at either end and the government will spend on that.”

BUILDING THE BRIDGE OF DREAMS

The construction of the bridge has been met with both plaudits and criticism. Basunia, a professor emeritus at the University of Asia Pacific, said he heard things like – “this bridge wants lives, seeks blood”, but nothing could stop the project.

Discussions over the 6.15-km bridge date back almost two decades. In July 2001, Hasina laid its foundation stone at the Mawa docks.

In 2004, the Japan International Cooperation Agency, or JICA, carried out utility surveys and pre-feasibility studies and advised building the bridge at Mawa-Zajira point.

During the regime of the military-backed caretaker government in 2007, another feasibility study was carried out with the assistance of the Asian Development Bank. In August that year, the Executive Committee of the National Economic Council or ECNEC approved the project with a budget of Tk 101.62 billion.

The following year, the Awami League vowed to undertake the project in their party manifesto for the national election and upon being elected, took up plans to link a railway with the roads of the bridge.

In January 2009, the cabinet committee on government purchase approved a tender to choose a company to supervise the construction of the project and later called for a tender to appoint a consultancy firm for the bridge in December.

In January 2011, the ECNEC approved a revised budget of Tk 205.07 billion.

The World Bank, ADB, JICA and IDB were supposed to fund the project. In October 2011, the World Bank complained about corruption in the project and suspended its decision to lend $1.2 billion. It finally withdrew the decision to finance the construction in June 2012.

Basunia thinks the project faced its greatest challenge when the global lender pulled out of the plan to co-finance the project.

“It was a matter of the country’s image, along with economic and political challenges. The prime minister overcame the challenges with sheer determination.”

[Writing in English by Syed Mahmud Onindo; editing by Osham-ul-Sufian Talukder and Turaj Ahmad]