Déshydratation naturelle et mécanisée de sédiments : étude des processus mis en jeu et applications

Abstract : Dredging operations produce large amounts of sediments with high water content, that are difficult to handle. Storage management and future reuses need to reduce the water content of sediments. Natural and mechanical dewatering of sediments meet this need. The most economic and eco-friendly method of dewatering is natural dewatering. Dewatering period can be reduced with suitable technical means such as adapted plough or scarifier for sediments, operating under defined dewatering criteria. The natural dewatering process was investigated and reproduced at the laboratory scale by performing Natural dewatering test and Shrinkage test coupled with shear measurements (vane shear testing). Nine sediments have been considered: seven dam sediments, two marine sediments and a kaolinite clay. A relationship Su = f(IP) has been established. It allows to deduce the undrained shear strength Su from only a measurement of water content. It allows to state on the right moment to put in operation the specific tools for ploughing and returning over or scarifying sediments stored. These tools can move in the sediments (adapted plough) or roll on the sediments (scarifiying roller) or roll on banks of sediment storage basin. Another way to dewater high water content sediments concerns a mechanical device. Thus a new method of continuous dewatering has been investigated using a prototype machine patented and referenced as KDS® sludge press. This type of press was not adapted for dewater sediments. Full of dewatering tests have been undertaken and performed with this prototype concerning some of sediments (see natural dewatering testing) and sandy clayey mixtures. It has been shown that KDS® press is able to dehydrate sediments including fine sandy sediments without excessive maintenance. Some adaptations and improvements of KDS® press to dewatering sediments are finally suggested.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-02292209
Contributor : Abes Star <>
Submitted on : Thursday, September 19, 2019 - 3:04:17 PM
Last modification on : Monday, September 23, 2019 - 12:19:55 PM

Identifiers

  • HAL Id : tel-02292209, version 1

Citation

Beatriz Boullosa Allariz. Déshydratation naturelle et mécanisée de sédiments : étude des processus mis en jeu et applications. Génie civil. Normandie Université, 2018. Français. ⟨NNT : 2018NORMC285⟩. ⟨tel-02292209⟩

Share

Metrics

Record views

59