At the time of its construction, the Stonecutters Bridge in Hong Kong was the largest stay cable bridge in the world, spanning 3,340 feet (1018m) and a total span of 5,236 feet (1,596m). CTLGroup employed 15 years of prior experience to perform qualification testing in accordance with PTI’s “Recommendations for Stay Cable Design, Testing and Installation” and to validate the watertightness of the protective coating per SETRA/CIP’s “Cable Stays – Recommendations of the French Commission on Prestressing”.
A total of eleven (11) tests were performed for this project ranging including five (5) fatigue tests, five (5) static tests and one (1) watertightness test. Testing was performed on the worlds’ largest stay cable test frame with capacities of 9,600 kips (42.6 MN).
Fatigue testing was performed with load ranges up to 115.5 ksi (796 MPa) and a stress range of 29 ksi (200 Mpa) applied over 2 million cycles. CTLGroup’s wire-break detection system was employed throughout testing, which can detect individual wire breakage via the use of multiple high-performance accelerometers. Static testing of individual stay cable assemblies was performed to assess the strength as compared to the minimum ultimate tensile strength (MUTS) to verify the design capacity. Watertightness testing was performed to assess the corrosion protection system of the stay cable system ensuring that the system retains the integrity throughout its service life. The cable was stressed axially, and a bending moment induced to prescribed levels. One end of the cable was confined and surrounded by dye water to monitor potential ingress of water while a cyclic temperature was applied to the system.
The tested samples were found to be in compliance with applicable standards, requirements and specifications. The Stonecutters bridge successfully opened for traffic in December of 2009.