Stay Cables

Over the last 30 years, Freyssinet’s Stay Cables have been recognized as the most reliable, durable, robust and technically advanced system available in the world. The current state-of-the-art Freyssinet HD Stay Cable System is the culmination of years of testing, research and development; complimented with the practical expertise achieved through the installation of Freyssinet cable stays on well over 100 cable stayed structures including many of the most prestigious and impressive projects built during this period. Its basic principle of independent strands within a given stay cable offers many advantages:

• The installation & tensioning of each strand individually
• Individual protection against corrosion
• The possibility of individual removal & replacement
• Installation with lightweight and extremely efficient equipment
• No practical limit on stay cable capacity or length

Freyssinet’s HD stay cable has been, and is in, a perpetual state of refinement and improvement. Perhaps the most obvious advantage is with Freyssinet’s patented ISOTENSION process used to install, tension and adjust stay cables.

The Freyssinet HD Anchorage is the most compact stay cable system and it performs all required functions within the anchorage assembly:

• It provides corrosion protection to the unsheathed ends of strands using a patented “stuffing box” and refined waterproofing details
• Unparalleled axial fatigue resistance (2 mio cycles with 300 MPa amplitude and 45% UTS upper load) due to Freyssinet’s fatigue resistant wedges
• Unparalleled resistance to bending fatigue at the anchorages through the use of Freyssinet’s patented “bending filter/ stuffing box” that limits the bending stress that may be transferred to each individual strand
• It simplifies end anchorage designs as smaller openings and reduced access area is required
• It enables easy initial installation, cable force adjustments and load monitoring.

All Freyssinet components have been intensely tested and exceed all the performance criteria according to the latest PTI & CIP industry standards.

For very aggressive environments or for use with multi-tube saddles, Freyssinet recommends the use of the patented COHEStrAND®—a specialized galvanized or a 7 wire galfanized steel strand with a bonded HDPE extruded sheath to allow to transfer the force through the sheath.

To ensure aerodynamic stability, Freyssinet has developed a number of patented devices such as internal elastometric & hydraulic dampers, internal radial dampers and pendular external dampers. For some exceptional cases, where dampers are insufficient, cross ties are installed to control stay cable vibrations due to parametric excitation or other sources beyond the control of ordinary damping devices. Freyssinet also provides double helical ribs on the exterior of all its standard stay cable sheaths. These external helical ribs were developed by Freyssinet for the Normandy Bridge to inhibit development of rain/wind induced vibrations which can create violent, large-scale amplitude cable movements under relatively benign weather conditions. Such external ribs are now routinely required on newly designed structures.

References:

• Go to the Projects section to review the full references list.