The first major cable-supported bridge of its kind in Bangladesh.

The US$45 million (£29 million) Shah Amanat bridge (previously known as the Third Karnaphuli bridge) is a 950m long bridge comprising three 200m extradosed main river spans, two 115m side spans and a 130m approach viaduct section spanning the Karnaphuli River in Chittagong, the second largest city in Bangladesh.

Rendel was appointed by the China Major Bridge Engineering Company (MBEC) to design the bridge, incorporating innovative design techniques and using the latest software, particularly in relation to the cable supported structure and seismic design. We completed the detailed design, supervised the critical aspects of ground investigation and had ongoing involvement on site in providing technical advice during construction.

The prestressed concrete box girder deck was constructed by the balanced cantilever technique. Seismic devices were provided at each of the four piers to transfer loads from deck into the substructure. The crossing carries two full lanes (3.65m wide) and two narrow (1.65m wide) lanes of traffic on each carriageway as well as providing access for pedestrians.

The bridge was officially opened on 8 September 2010 and was shortlisted for that year’s BCI International Project of the Year 2010 Award.

Rendel, Ingerop’s UK subsidiary, provided Management Support Consultancy services, which included value engineering design to accelerate construction, on the US $2.9 billion Padma Multipurpose Bridge Project (PMBP).

Funded by the Government of Bangladesh, PMBP is a two-level, steel truss bridge with a four-lane highway on the upper level and provisions for a single-track railway on the lower level. The upper and lower levels act compositely with a reinforced concrete deck slab. The bridge has a total length of 6.15 kilometres and a width of 22 metres at upper deck level. As well as rail and road, the bridge carries utilities including a high pressure gas pipe and telecommunication lines. The project is considered one of the most challenging construction projects in the country’s history, as in response to very challenging foundation conditions, it features driven piles over 125m long.

It is the largest bridge in the Ganges-Brahmaputra-Meghna river basin, located approximately 40 kilometres southwest of Dhaka. It connects the south-western region to the rest of Bangladesh to encourage and facilitate economic growth through the transport of people, goods, natural gas and telecommunications.

In addition to the construction of the bridge itself, there is an elaborate system of associated road constructions including two toll plazas and bridge end facilities, a 13.6 kilometre, four-lane, dual carriageway approach road, culverts, small bridges, underpasses, service roads and service areas for residential accommodation. Complex riverbank protection/training works of 14 kilometres in length were also constructed. The social and environment impacts were carefully managed via the implementation of a Resettlement Action Plan (RAP).

Rendel provided Management Support Consultancy (MSC) which included project management of the entire scheme including contractual and commercial advice; engineering and technical support and advice; budgetary and financial management; quality control and assurance; advising on dispute settlement; and the implementation of the social safeguard plans (environment, resettlement, etc.).

Rendel also managed several specific supplementary engineering studies. These included re-detailing of the main bridge precast roadway deck slabs to improve the buildability and enhance longevity; and the design and implementation of a dehumidification system through the interior of the 6.15 kilometres truss main bridge in association with Ingerop, who modelled the completed assembled truss module using 3-D CFD.

Rendel also completed the original Padma River Crossing Pre-feasibility Study in 2000.