DISCOVER Magazine #7

Dynamics of nature

Published in category: Dredging

The changing focus of civil works construction

Johan_Pennekamp_R&D_Manager_Water_Soil_Interaction_DeltaresJohan Pennekamp
R&D Manager Water Soil Interaction,

Can dredging equipment keep up with the rapidly developing fields of eco-engineering and geotechnics? To rise to the challenge, R&D cooperation across the industry is key, says Johan Pennekamp. He is R&D Manager Water-Soil-Interaction at the Dutch applied research institute Deltares, as well as Vice President of the Central Dredging Association (CEDA) and Chair of CEDA Netherlands.

Last century’s colossal construction projects underpin the Netherlands’ infrastructure and coastal defences. Yet, these engineering wonders have also left their scars. In some cases such as Lake Markermeer, dams, dikes and reclaimed land have cut off waterways, leading to turbid waters and dramatic declines in fish and bird populations. It’s a long way from today’s focus on ‘Building with Nature’, comments Mr Pennekamp.

“From the Middle Ages, the people here in the Lowlands have been maintaining rivers and canals. But it was during the sixties and seventies that we began looking at how nature organises itself, the effects of silt agitation, rock breaking and transporting different mixture densities. That period became the roots of today’s fundamental knowledge in the Dutch and Belgian dredging industry.

“I think our prime achievement from those years has been providing the dredging industry with insight into physical dynamics. That led to a change in the technology and the process of dredging. Back then, dredging was a matter of craftsmanship, where the highly experienced dredge master listened to the pumps, read the manometers and felt it in his gut. The performance came down to experience, not necessarily something you could predict or control. Now we have a very good understanding of those dynamics and energies. That’s not only a great headstart for dredging contractor productivity and efficiency, it’s also become something we can teach. Dredging used to be an art, now it’s also a science.”

Applying fundamental dredging research, contractors can better understand the dredging process, calculate conditions and evaluate risks.

However, today’s focus is shifting from mechanical construction to eco-engineering and geotechnics. Why? Because contractors face increasing regulatory and societal demands to reduce the environmental impact of population growth and economic development.

“These fields combine dredging knowledge with natural ecological dynamics, extending toward biological and chemical processes in dredging solutions. This is where Deltares is increasing our understanding of unconventional construction materials – from soft soils to organic solutions. Chemical compositions, salinity – theseare very important factors to get the proper results with the productivity required from the dredging industry.”

As expertise in these areas increases, so too does the demand on the industry to develop new technical innovations. Mr Pennekamp believes Joint Industry Projects (JIPs) hold the future of important technology breakthroughs. He says that while the industry’s top players remain fierce competitors, when it comes to pre-competitive cooperation, they have shown pragmatic consensus.

“The Dutch and Belgians tend to join hands when they can’t reach it on their own. Whether sharing each other’s findings or financial investment in innovation, my experience is that there is very good sparring between contractors at a very high level and that is pushing successful innovation.”

As for turbid Lake Markermeer, the future looks clear with a new project starting in 2016. The ‘Marker Wadden’ project (pictured) will construct islands, marshes and mud flats from the accumulated sediment to form a unique ecosystem and boost biodiversity.

Preparing For The Deep-Sea Mining Boom

Despite the economic slowdown dampening expectations, many contractors and yards are still keeping one foot in the deep-sea mining market. Deltares is very much involved, including advising Nautilus’ seafloor operations planned at the Solwara 1 Project in the Bismarck Sea of Papua New Guinea. Johan Pennekamp: “At 2 km depths, you can’t extrapolate knowledge of a cutter suction dredger at 30 metres. You have to start with the basic knowledge of the dynamics. We still don’t know everything about the deep-sea, but having that fundamental knowledge, we were the first to give a very good estimate of the energies involved.”

Developing the delta – Bangladesh

Deltares does a lot of work in Bangladesh, sharing knowledge and models to develop infrastructure on the enormous Ganges-Brahmaputra-Meghna Delta. The river area hosts a huge population and, like the Netherlands, dredging solutions play a key role in the country’s economic development. However, in contrast with heavily developed waterways in the Netherlands, the Brahmaputra is a very dynamic braided river. To make it navigable for transport, Bangladesh is turning to Deltares to develop nature-based engineering for adaptive river training. Instead of rigid construction, the dredging solutions need to interact with the dynamics of the river.
For a look at Damen’s role in Bangladesh, see page “A supportive partner”.

Soft solutions for subsiding Jakarta?

Indonesia suffers from severe coastal erosion as well as land subsidence. Strengthening the current sea dike in Jakarta became a priority and Deltares conducted the hydraulic studies. Johan Pennekamp: “The problem from a conventional dredging standpoint is that Jakarta has no sand and transporting from West Java and South Sumatra over hundreds of kilometres is not ideal and not cheap. So the question was posed to us, what can we do with soft soils? What can we create with materials that are not traditional construction materials? That’s where better understanding and innovation can make a difference.”

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