NEES Laboratory Facilities

Each of NEES's 15 shared laboratory facilities enables researchers to explore a different aspect of the complex way that soils and structures behave as a result of earthquakes and tsunamis. The laboratories fall into five general categories: shake tables, tsunami wave basin, geotechnical centrifuges, field experimentation and monitoring, and large-scale laboratory experimentation.

Shake Table Facilities

Three of the NEES laboratories provide large platforms that can be shaken dynamically by computer-controlled actuators. Test structures, such as scale models of building or bridge components, are built on the table and outfitted with sensors to measure movement and strain. When the table is shaken, it reproduces realistic earthquake ground motions that create strong forces on the test structures. There are three facilities of this type, located at University of Nevada at Reno, University of California at San Diego, and University of Buffalo - SUNY.


Tsunami Wave Basin Facilities:

Oregon State University is home to the NEES Tsunami Wave Basin. This consists of a large, precisely constructed water basin where scale models of shorelines and coastal structures can be positioned. A powerful wave generator can create single waves or varying patterns of repeating waves, allowing investigators to explore the complex effects of tsunamis and storm surge waves on coastlines. Researchers can also use the basin without the wave generator to study how tsunamis are created by underwater landslides or volcanic eruptions.


Geotechnical Centrifuge Facilities:

Researchers use a geotechnical centrifuge to study soil-related issues associated with bridge and building foundations, embankments, slopes, shorelines, retaining walls, and tunnels. A small-scale model of a specific site is constructed in a container. For example, this could be a bridge on a hillside next to a river. The container with the model is attached to a large arm that rotates the container at high speeds. As the container is spun around, an increased "gravitational" acceleration is applied (this increase in "gravity" is needed in order to compensate for the reduced scale of the model). Two centrifuge facilities have been developed, one at the University of California at Davis and the other at Rensselaer Polytechnic Institute.

Field Experimentation and Monitoring Facilities

Three sites provide mobile or field-installed test equipment so researchers can study the behavior of building structures and soils during actual or simulated earthquakes.

Mobile field equipment at University of Texas at Austin generates earthquake-like vibrations by shaking the ground with powerful mechanical devices mounted to heavy trucks. The facility at University of California at Los Angeles has mobile shakers that apply vibrations directly to buildings, bridges, and other structures. The University of California at Santa Barbara maintains two permanent field laboratories, each consisting of a concrete test structure (building model), small shakers mounted on the structure, and sensors installed on the ground throughout the site.

Large-scale Laboratory Experimentation Facilities

Large indoor testing facilities allow researchers to apply dynamic earthquake forces on large models of building structures, bridges, and other infrastructure. Steel test frames or rigid concrete walls and floors with computer-controlled actuators are used to apply large forces, similar to those exerted during earthquakes. Five such facilities are located at University of Minnesota, University of Colorado at Boulder, University of Illinois at Urbana-Champaign, Lehigh University, and University of California at Berkeley . The sixth, at Cornell University, also includes a large split-box container that can be used to test the impact of large ground movements on buried pipelines.