Wave Transmission and Mooring-Force Characteristics of Pipe-Tire Floating Breakwaters

摘要

Wave transmission and mooring-load features were tested for a floating breakwater created from massive cylindrical members (steel or concrete pipes, telephone poles, etc.) in a matrix of scrap truck or automobile tires. The Pipe-Tire Breakwater (PT-Breakwater) was tested at prototype scale using regular waves ranging in height from 0.15 to 1.78 meters and period from 2.6 to 8.1 seconds; water depths ranged from 2.0 to 4.6 meters. Two designs were tested--the PT-1 module, composed of steel-pipe buoyancy chambers and truck tires, and the PT-2 module, composed of telephone poles and car tires. Each design was 12.2 meters wide in the direction of wave propagation and was held together by conveyor-belt loops. Wave attenuation and mooring-force features were established based on data from 402 separate runs in which incident and transmitted wave heights were recorded, along with the tension in the seaward mooring line. Test results are compared with those of earlier experiments made on the Goodyear floating tire breakwater. The construction of these PT-Breakwater modules is outlined, along with the cost estimates for construction of components. A breakwater buoyancy test was made and the flotation requirements calculated. The influence of stiffness on the mooring system was experimentally investigated and conveyor-belt material tested to the point of failure. Design curves for determining the proper anchor requirements and breakwater size and given.