NEHRP Clearinghouse

Title
A Laboratory Study of the Fluid-Structure Interaction of Submerged Tanks and Caissons in Earthquakes.
File
PB284957.pdf
Author(s)
Byrd, R. C.
Source
National Oceanic and Atmospheric Administration, Rockville, Md. Office of Sea Grant.; California State Resources Agency, Sacramento., May 1978, 167 p.
Identifying Number(s)
UCB/EERC-78/08
Abstract
An experimental study comparing the results of measurements of forces on a submerged tank model due to earthquake excitation is presented. The experimental results are compared with analytical solutions for the case where the model is submerged in water of depth equal to 2.5 times the tank height and for the case where the depth exactly equals the height. Details are presented for the design of a 1 to 100 scale model of a circular cylindrical structure which is 34 meters in height with a mass of approximately 250,000 tons. The model includes a foundation system which simulates elastic half-space soil stiffness in three degrees of freedom. The experimental results are presented in the form of inertia coefficients measured in harmonic motion at varying amplitudes and over a frequency range of 0.3 Hz to 2 Hz in prototype scale. Coefficients are presented for horizontal, vertical, rotational, and horizontal-rotational coupling. The relationship between these coefficients and the physics of the fluid-structure interaction are discussed in detail.
Keywords
Dynamic response; Ground motion; Computer programs; Earthquake engineering; Earthquakes; Offshore structures; Hydrodynamics; Equations of motion; Force; Fortran; Storage tanks; CONTAPE computer program; SUBTANK computer program; MASSCAL computer program; Pressure; Hydrodynamic forces