Optimum Safe Hydraulic Design of Culverts

Z. M. Al-Qaisi, Atheer; K. Al-Shukur, Abdul-Hassan; A. Al-Delewy, Abdul-Hadi

	Optimum Safe Hydraulic Design of Culverts
Journal of Engineering and Sustainable Development
Article 1, Volume 12, Issue 1, 2008, Pages 66-88
Authors
Atheer Z. M. Al-Qaisi; Abdul-Hassan K. Al-Shukur; Abdul-Hadi A. Al-Delewy
Abstract
This research aims at obtaining the "Optimum safe hydraulic design of culverts", taking into consideration the cost of excavation, bedding, material, compacted fill, hunches, protection works, and additionally involved head loss. Because of numerous shapes and materials of culverts, the wide-fame among them have been selected in this research, namely, reinforced concrete box culverts of both rectangular and squared shape, and pipe culverts of circular shape with materials of reinforced concrete, cast-iron, asbestos-cement, and ductile-steel. To be close to field conditions, discharges of (0.5, 1.0, 1.5, 2.5, 5.0, 10.0, and 15.0m3/s) have been selected to represent small, medium, and big discharges; culverts lengths of (5, 10, 15, 20, 25, 35, and 40m) have been selected to represent short, medium, and long structures. However, typical trapezoidal earthen irrigation channels have been considered to accommodate the respective culverts. To prepare the optimization model, an objective function has been formulated to cover all aforementioned costs. The optimization model involved all structural and hydraulic design constraints. The established non-linear optimization model is solved by the modified Hooke and Jeeves direct search approach. A computer program is developed to handle the aimed solution. The following categories of analyses have been considered: 1. Cost as a function of discharge (for the different selected lengths). 2. Cost as a function of length (for the different selected discharges). 3. Number of vents as a function of discharge (for the different selected lengths). 4. Number of vents as a function of length (for the different selected discharges). 5. Dimensions of the culvert as a function of discharge (for the different selected lengths). 6. Dimensions of the culvert as a function of length (for the different selected discharges). The results showed the following: 1. The computer program is efficient in giving the results. 2. The optimization process automatically excluded the pipe culverts, whereas the reinforced concrete box culverts are the optimum types for all considered discharges and lengths. 3. The discharge, rather than length, is the dominant factor controlling costs, number of vents, and dimensions of the culvert.

Statistics Article View: 81 PDF Download: 16