16 December 2014
16 December 2014
QuakeWrap explains, the repaired tower is located in a congested site in Los Angeles, California, US and is one of many such towers worldwide that could benefit from this technology.
According to QuakeWrap, with the increased use of mobile communication worldwide, existing cell phone towers must be structurally upgraded to accommodate loads from additional antennas. In many cases, these towers are located in congested urban areas where zoning restrictions limit the number of towers being built, and the use of guy wires is not an acceptable option. For these types of self-supported structures, cell tower owners and carriers must find a compact strengthening system that can be used in tight spaces, and is non-disruptive to service. QuakeWrap says it provides a solution.
The first application of this technology was recently completed for Crown Castle International, which QuakeWrap describes as the largest provider of shared wireless infrastructure in the US. A 55 foot (17 metre) high cell tower located in a high seismic zone in southern California was strengthened to increase its load-carrying capacity. The monopole structure is made of a hollow spun precast concrete tube with a thickness of less than 2 inches (or 50 mm). In a technique developed by the QuakeWrap engineering team, it says the tower was modelled and analysed to determine the strengthening required at various elevations along the height of the tower. It was determined the lower two thirds of the tower required tension reinforcement; this was achieved by bonding carbon fibre reinforced polymer (CFRP) sheets saturated with epoxy resin to the surface of the tower.
QuakeWrap says the high structural performance of its fibre reinforced polymers (FRPs) combined with their low profile and flexible application made an ideal solution for the strengthening of the tower. Layers of carbon and glass fabrics, in combination with its patented PileMedic jacket strengthening system, and proprietary epoxies and resins provided a fast and economical solution as demonstrated in a video posted to QuakeWrap’s YouTube channel.