Earthquake Drains in Brunswick County, NC
Did you know Brunswick County, NC is in an earthquake zone?
Neither did we, until we started our latest Assisted Living project there in late 2019. Coding in that area requires special soil liquefaction mitigation. Liquefaction is a common problem in earthquake-prone areas where soils lose strength due to the ground motion and behave like a viscous liquid, damaging overlying structures. The earthquake drain ground improvement method minimizes bearing capacity failures and settlement during and immediately after a seismic event. It mitigates liquefaction by limiting excess pore pressures generated during seismic events to levels less than those that could trigger liquefaction.
Installed in March and engineered by Keller, our earthquake drains were installed by vibrating the insertion mandrel during penetration and removal. Typically, the insertion mandrel consists of a heavy-gauge steel pipe with three equally spaced fins to transfer vibrations to the adjacent soil.
The 3 inch diameter drain core is tightly wrapped with geotextile filter fabric (selected for its filtration properties), allowing free access of pore water into the drain. The geotextile wrap is very durable and able to withstand the handling and abrasion that occurs during installation.
These drains are a great example of an engineering solution that prevents long-term catastrophic stability issues and helps maintain the safety of a building. At CCC we are always learning new ways to build better products for our clients!