The Modular Geometry of Precast Concrete for Highway Drainage Channel

Abstract

This research is based on the phenomenon of failure of masonry drainage channels, especially in locations with
steep to very steep slopes. Observing the flow behavior and mechanical properties of the masonry, it is possible due to the
erosion of the bottom to the foot of the channel so that the masonry collapsed and/or due to side soil pressured which caused
the masonry failure. It could be overcome by replacing the masonry with precast concrete. The obstacle of precast concrete
implementation in low cost projects is involvement of heavy equipment when erecting precast concrete for drainage channel
(e.g. U-Ditch) which is available on the market. This research aims to design the geometry and dimensions of precast
components for open channel of drainage with limitations: component weight (kg/component) is limited so that it could be
lifted by man power and is able to flow a design discharge ≥ 0.5 m3/s at 1.5 m /s. Channel was divided into 4 components,
namely: foundation (F), bed (B, type I and II), wall (W), and channel cap (C) with 6 cm of thickness, 1:10 (H:V) of wall
slope channel, and 75 cm of each component length. Each component weighs no more than 50 kg, so could be carried out
without heavy equipment when constructed. The weights of each component are 39.8 kg, 45.36 kg, 28.8 kg, 37.8 kg, and
21.45 kg for foundation, bed type I, bed type II, wall, and channel cap.