NEES Overview

A 4-year project is under progress for the upgrading, development and preparation to participate in the NEES Collaboratory, of the existing 100 g-ton geotechnical centrifuge at Rensselaer Polytechnic Institute (RPI) in Troy, NY. This project was submitted in Equipment Category B (centrifuge research equipment) of Program Solicitation NSF 00-6, Network for Earthquake Engineering Simulation (NEES): Earthquake Engineering Research Equipment.

Especially important in the vision embodied in the project is the use of dense arrays of advanced sensors and of high speed cameras to provide high resolution measured model response. In conjunction with the networked data acquisition system with remote access capability, this will allow for a quantum jump in the use of the data at RPI and throughout NEES, including teleobservation, shared-used of data, test visualizations, system identification, numerical computations and development of model-based simulations. In addition, the upgraded and new equipment will allow for teleoperation/control over the Internet, which at the beginning will focus on the use of the robot by remote observers. A specific teleobservation / teleoperation pilot project is proposed with the participation of the U. of California, San Diego (UCSD). The five PIs are Profs. Dobry, Abdoun, Zeghal and Zimmie from RPI and Prof. Elgamal from UCSD; this team covers all areas of expertise needed for a successful project, ranging from centrifuge model testing and equipment development to system identification, visualization and computational simulations.

Background

Rensselaer’s centrifuge was commissioned in 1989 and started conducting physical model simulations of soil and soil-structure systems subjected to in-flight earthquake shaking in 1991. In this decade of successful operation, the facility has published results of about 360 earthquake-related model simulations, served as the basis for 12 Ph.D. theses at RPI (10 Ph.D. theses in the last five years), contributed to the research of RPI faculty and students as well as of dozens of visiting scholars and outside users from the US, Asia, Europe and Latin America, and provided data and research results to many people and organizations around the world This centrifuge earthquake research has been conducted with two existing one-dimensional in-flight shakers, which can accommodate respectively 90 kg and 400 kg payloads.

Upgrading Our Centrifuge

The next-generation earthquake engineering capability for the RPI centrifuge includes:

  1. a 2D in-flight earthquake shaker (two prototype horizontal components) and associated 2D laminar box container to allow for more realistic 2D modeling;
  2. a four degrees of freedom (4D) robot capable of performing in flight operations such as construction and excavation, pile driving, ground remediation, cone penetration, and static and cyclic loading tests without stopping the centrifuge;
  3. a networked data acquisition system with Internet Teleobservation / Teleoperation capability, to be linked to the high-speed RPI Gigabit Ethernet Backbone;
  4. two high-speed cameras and image processing software;
  5. development of a new generation of advanced and improved sensors capable of providing a better resolution of the measured model response;
  6. other equipment aimed at increasing the capability of the centrifuge to test a greater number and wider variety of earthquake engineering models.

Centrifuge Center Video