Author(s)

A. M. Ghazali & S. H. Awedat

Abstract

A conceptual implementation of the use of prestressed concrete cylinder pipes (PCCP) as composite breakwaters for small ports is outlined in this paper. These pipes are of 4 m diameter and 7.5 meter long while weighing 73.0 metric tons and are produced by the Great Man Made River Project (GMRP) in Libya for water conveyance. The idea is to utilize such pipes in vertical alignment with a submerged rubble mound base so that they behave as composite breakwater. In order to confirm analytical stability computations for such composite breakwater, a two-dimensional physical test model was performed for various water depth and wave action conditions. Test measurements included significant and maximum wave heights, and average and peak wave periods. Model tests were documented by visualization before, during and after all test runs. Stability of the composite breakwater were determined for non-breaking wave conditions, furthermore the design criteria for this use of Prestressed Concrete Cylinder Pipes as composite breakwater is outlined. Keywords: prestressed concrete cylinder pipes, composite breakwater, nonbreaking waves, pipe sliding, pipe overturning, design criteria. 1 Introduction One of the largest civil engineering projects in the world is being executed to deliver water at a rate of about 6 million m3 per day from the south to the coastal North part of Libya and it is called the Great Man-Made River Project (GMRP). The prestressed concrete pipes utilized for this project are of massive sizes, where nonstandard and non-proven technologies have been used in the manufacturing process. This reality coupled with the stringent quality control

Keywords

prestressed concrete cylinder pipes, composite breakwater, nonbreaking waves, pipe sliding, pipe overturning, design criteria.