Earthquake drains are manufactured, high flow capacity vertical drains that are used to mitigate liquefaction in earthquake zones.
- Reduce liquefaction potential
During installation, the mandrel holding the earthquake drains is vibrated during insertion and removal. The mandrel is typically composed of heavy-gauge steel pipe with three equal fins that are used to transfer vibrations to soil surrounding it. Due to the vibrations, granular soils are densified. This serves to help in the liquefaction mitigation process.
The drain core of the earthquake drains is a 75mm pipe and is wrapped in geotextile fabric that was selected for its filtration abilities and its durability to endure the handling and abrasion of the installation process. While this is a typical design, there are several cores and fabric types that can be used to fit a variety of drainage problems and soil types. This construction allows ground water unlimited access into the drain, while stopping the piping of fines from adjacent soils.
Mitigating liquefaction using earthquake drains is important for situations such as support of embankments, reduction of lateral spreading, containment of densified ground, support of floor slabs, and reducing seismic deformations of pile groups. Earthquake drains can be combined with other ground improvement techniques to provide a complete solution to your site.