Soil-structure-water interaction page

Centrifuge Modeling of Soil-Structure-Water Interaction in Buried Reservoirs

Researchers: Brian Morales (MS, 2020) & James Heins (MS, 2021)

Abstract:

Buried water storage reservoirs are the primary source of water in many cities along the western coast of the U.S. These structures play the critical role of providing water for post-earthquake damage mitigation and conveying potable water to the affected areas. Current design methods for underground reservoirs rely on simplified assumptions that are not properly validated or directly applicable. The purpose of this experimental research program is to improve the earthquake resiliency of cities that rely on underground water reservoirs by investigating the seismic response of these structures through multiple phases of centrifuge experiments. Phase I of the experiments consisted of five centrifuge tests that isolated and investigated the hydrodynamic response of a water reservoirs subjected to wide range of earthquake motions. Phase II will consist of several centrifuge tests that will add the complexity of surrounding soil to investigate the effects of all the components of the soil-structure-water system. Preliminary results of Phase I experiments show that the hydrodynamic pressure response is proportional to the peak ground acceleration and at resonant sloshing, pressures developed are significant even long after the motion has ceased (in some instances up to 5 minutes). Results from both phases of experiments will be used to calibrate numerical models and guide future design requirements.

       

SSWI centrifuge test design
Figure 1: Phase II centrifuge test in flexible shear beam container depicting approximate instrumentation locations
Input motion to the shake table mounted on the centrifuge bucket
Figure 2: Top: Input motion, Bottom: Pressure response at base of the tank during resonant sloshing

 

References:

  1. Morales, B., Sawamura, Y., Ziotopoulou, K., Hashash, Y. M. A., and Alkhatib, K. (2021). Centrifuge Modeling of Hydrodynamic Loads in Water Storage Tanks. San Fernando Earthquake Conference – 50 Years of Lifeline Engineering, ASCE-UCLA, Los Angeles, California, February 7-10. Abstract submitted