详情

原文传递 USE OF SAND-SILT SEPARATIONS AND SILT DUMPS IN THE STOCKPILING OF DREDGED MATERIAL

题名：	USE OF SAND-SILT SEPARATIONS AND SILT DUMPS IN THE STOCKPILING OF DREDGED MATERIAL
作者：	Stefaan PAUWELS; Martin OCKIER; Peter NIELSEN; Willem VAN CROMBRUGGE
关键词：	SAND-SILT SEPARATIONS ; SILT DUMPS ; DREDGED MATERIAL
摘要：	Between the new and old reaches of the Gent-Bruges canal at Beernem lies 50 hectares of land. A permit has been issued for a sand borrow on this land and for stockpiling dredged sludge. Before the sludge is transferred to the borrow pit, used as a confined disposal area it is first pumped to one of the six separation dumps at the site, which have overflows to two siltclay dumps. The dumps have been designed to obtain a maximum separation of the incoming dredged sludge into a sand fraction with a grain size greater than 60 micron and a silt-clay-clay fraction with a grain size below 60 micron. Careful management of the dumps allows the sand to be left behind in the separation dump, while the silt-clay settles in the silt-clay dumps. The separation dumps are laid out on a slightly sloping bottom. Mildly turbulent flow had to be established in the separation dump. The dredged sludge is pumped as a slurry with a dry matter content of 12% to become a low-viscose mixture. The dry matter content in the slurry line was continuously monitored. The delay time in the silt-clay dumps had to be sufficiently long (at least 24 hours) to allow the sedimentation of all fines. The first results show that there is about 30 % silt-clay fraction left in the separation dumps. In the silt-clay dumps there is about 20 % sand fraction. In order to reuse the sand recovered from dredging operations a series of tests must be carried out that approve conformity with the applicable regulations. On this basis a certificate of use can be obtained. These regulations are relatively new and have not yet been applied to dredged sand. Reusing the fines silt-clay is not straightforward, not only due to the risks of a higher contamination level but also up to now, primary raw materials have been used practically exclusively for clay applications.
总页数：	Proceedings of the 30th PIANC-AIPCN Congress. Sydney Australia. 22-26 Sept. 2002. pp13
报告类型：	科技报告