AbstractIn August 1993 Baggermaatschappij Boshalis was awarded a contract for the construction of a breakwater (1400 m parallel to the coast) and four rock groynes (180 m each) in Malaysia. The award was based on the company's alternative design, which was to use 11 and 20 t concrete armour units (tetrapods) totaling 115 000 m3 of concrete and 2.1 x 106 t of rock with sizes from 50 mm to 9.0 t. The quantities of the various rock grades chosen in the alternative design were optimized to suit the assumed production possibilities of rock block sizes from sources in the area. After award of the contract, a new quarry only 8.0 km from the construction site was opened, the nearest existing quarry being 38 km away. The new quarry started deliveries on 1 April 1994 and completed them on 17 April 1995.A case history of the quarry is presented, emphasizing the economic importance of the rock fragmentation and the logistics common to most dedicated armourstone quarry operations. It describes the tender stage, the choice of quarry location and the choice of the various specified rock gradings made during the breakwater design process. The blasting procedures used to obtain the required gradings and quantities are discussed. The particular features and problems associated with opening and operating a dedicated armourstone quarry — for example, the selection plant, the stockpiling procedures, shipping and materials quality control procedures — are amplified upon.
Planning water use and quality control in a river basin / Planification de l'utilisation de l'eau et le contrôle de qualité dans un bassin versant fluvial