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Flowtite GRP-pipes documents resistance to severe earthquakes

News International-French

17 Jan 2013

A newly published technical note states that Flowtite GRP-pipes holds properties making them resistant to severe earthquakes. Glass fibre reinforced plastic (GRP) pipe systems are unique in the respect that they are more flexible compared to most other high-strength materials.

The chances of survival of structures subjected to devastating seismic loads depend mostly on two factors: their flexibility and their strength. Structures that are overly stiff will develop higher stresses than more flexible structures, and are thus more easily overstressed. This holds true for both buried and above-ground structures. GRP-pipes have sufficient strength to resist the stresses generated by the severest of earthquakes. This has been demonstrated by structural analysis, and verified in case studies. Information gathered over the years reveals that Flowtite pipes perform well in earthquakes. This is because of the inherent flexibility and strength of the pipe and the capacity of the joints to absorb ground movement.

Stiffer materials like steel and concrete do not have this flexibility and are therefore vulnerable to ground accelerations and peak velocity, as well as the associated ground strains.


Case Studies
In the last couple of decades Flowtite pipes have been exposed to large earthquakes in several parts of the world, and in all cases have remained in service with little or no need for repairs, while other structures have succumbed to considerable structural damage or collapse. The following table lists such references for Flowtite pipes, subjected to earthquakes of moment magnitude greater than Magnitude 5.0.

Below: known examples of Flowtite pipes subjected to severe earthquakes. The table lists four earthquakes in Turkey, one in Chile, one in Colombia and two in New Zealand. The sewer line in Christchurch has been exposed to two major earthquakes without any damage. The others have suffered earthquakes from M5.6 up to M8.8 with no damage reported.



Seismic analysis of properly designed glass fibre reinforced plastic pipe systems demonstrate that they are less vulnerable to damage than pipes made of stiffer materials. This has been verified by several cases where Flowtite pipes have been subjected to earthquakes of moment magnitude of up to 8.8, without disruption of service.

Flowtite Technology
Flowtite Technology is a part of the Amiantit Group, one of the largest pipe manufacturers in the world. Flowtite Technology has delivered state of the art GRP pipe technology for almost 50 years, and set up more than 70 plants or production lines worldwide.
Flowtite GRP-pipes have been delivered to a large number of projects for hydropower, water supply, wastewater, irrigation and industrial applications. Some of them are among the largest of its kind in the world. Flowtite Technology with its affiliates and subsidiaries are a world wide company with presence on all soils.