Efek Tegangan Geser Dasar yang Terjadi pada Lapisan Pelindung Terhadap Karakteristik Kemiringan Dasar Saluran

• Main Authors: Cahyono Ikhsan, Adam Pamudji Raharjo, Djoko Legono, Bambang Agus Kironoto
• Format: Article
• Language: English
• Published: Institut Teknologi Bandung 2016-12-01
• Series: Jurnal Teknik Sipil
• Subjects: Shear stress; base slope; armour layer; grainsize
• Online Access: http://journals.itb.ac.id/index.php/jts/article/view/3582/1821
• ISSN: 0853-2982; 2549-2659

Armouring is one of the development processes of armour layer on the base of a river, started from the movement of the transported base sediment of eroded surface reaching to stabile base layer condition or equilibrium, where there is no more transported base sediment. Armour layer is a type of gravel with almost uniform composition of granule gradation in surface base position which hampers the sediment moving above it. This research was carried out at the Hydraulic Laboratory of PS-IT UGM, using the main infrastructure of sediment recirculacy flume on the wall made from plexiglass in 10.00 m length, 0.60 m width, and 0.45 m height. The base slopes were 1%, 1.4%, 1.8%, 2.2%, and 2.6%. The flow debit was constant at 25 l/s, 30 l/s, 40 l/s and 45 l/s capacities. The material consisted of sand and gravel which was evenly mixed within 5 different variations of grainsize. At each running, there were two phases of eroded surface and equilibrium. The instruments used during the running were digital current meter, point gauge, sediment traps. Within the eroded surface process, the armour layer structure looked standing out in the base surface due to the granule critical shear stress of armour that was larger than the base shear stress, thus the armour layer was the structure of sediment granule with larger critical shear stress than bed shear stress.