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Research reveals microscopic effects of cutting soil, rock

2021-04-13 PENNY THOMAS, INTENT COMMUNICATIONS
research, dredging, 3D modelling, cutting, WODA, microscopic detail, numerical data

13042021 Xiuhan Chen credit TU Delft // chen_xiuhan.jpg (545 K)

Caption: Dr. ir. Xiuhan Chen said his research shows the microscopic effects of cutting “as if we are one of the soil grains”. Photo Credit: TU Delft

A 3D dynamic numerical model to examine the microscopic behaviour of soil, rock and water during cutting and dredging processes was the focus of a PhD thesis successfully defended by Dr. ir. Xiuhan Chen.

The doctor of Offshore and Dredging engineering at Delft University of Technology in the Netherlands told CEDA Industry News that the five-year project has culminated in a 3D dynamic numerical model, where cutting physics, whether of sand, cohesive soil or rock, can be observed at a microscopic level “as if we are one of the soil grains”. Such research has been carried out in the deep-sea mining industry, explained Chen, but has received less attention in the dredging industry.

The work is important, he asserted, to optimise the design and power consumption during dredging operations. “We need to understand how rock will behave to improve the design” of the cutting process required. “This had never been done specific to dredging. Only for drilling and that is different,” he said.

Chen’s research, which drew in expertise from across the industry, is based on theoretical analysis combined with practical experiment results to “make the data real”. He will now use his research to generate a database from which more accurate information can be applied to dredging works. For example, Chen explained, if a dredging company wanted to understand the force and power consumption of dredging certain rock, they can check the database for an answer.

Commenting on Chen’s 1 April presentation – Numerical Modelling for Underwater Excavation Process – Dr.ir. Sape Miedema, also of Delft University of Technology, praised Chen’s thesis and highlighted his active participation in various dredging industry fora.  

Chen is actively involved in CEDA and WODA (World Organization of Dredging Associations). Amongst others, he is General Secretary of the WODA Technical Orientation Committee (TOC) set up in 2019 during WODCONXXII in Shanghai. Consisting of members from each WODA organisation – EADA, CEDA, and WEDA – TOC’s role is to identify topics of common interest which could be developed into WODA Technical Reports or Technical Guidance Documents. 

Chen volunteered for the role of General Secretary of the first WODA working group on Reservoir Dredging (ResDred WG) – http://woda.org/reservoir-dredging/  – which has approximately 60 members. The ResDred WG is now working on guidelines for reservoir dredging – important work due to the build up of sediments in such bodies of water, and an industry first as such guidelines have “never been created before”. Chen fulfils the same role for the EADA ResDred WG.