05-16-2012, 09:14 AM
Earthquake response considerations of broad liquid storage tanks
Cambra, Frank J.
UCB/EERC-82/25, Earthquake Engineering Research Center, University of California, Berkeley, 1982-11, 193 pages (540/C35/1982)
This paper examines the influences of tank geometry and foundation stiffness variation on the simulated seismic structural response of a broad tank model. An empirical method for describing tank bottom plate uplift geometry is proposed which recognizes radial catenary force and foundation stiffness. Axial symmetric lift, static tilt, and dynamic shaking table tests were performed at the Univ. of California, Berkeley, Earthquake Simulator Laboratory. A structural geometric survey of a crude oil storage tank, measuring 63 ft 10 in tall by 289 ft 6 in wide, was conducted to establish a comparative base by which to evaluate the model tank eccentricities. It is concluded that the imperfections of the model tank defined by Fourier coefficients can be as much as an order of magnitude greater than those observed in the field. It is also concluded that foundation flexibility variation will significantly change the seismic response of tanks. Further, it is believed that out-of-round seismic vibration response, thought to be associated with eccentricities in tank fabrication geometry, will be less significant for large operating broad tanks resulting in lower amplitudes of asymmetric and higher order Fourier stress contribution. However, other parameters, such as uplifting, may still excite asymmetric and higher order Fourier response.
PDF 8.34 MB
Cambra, Frank J.
UCB/EERC-82/25, Earthquake Engineering Research Center, University of California, Berkeley, 1982-11, 193 pages (540/C35/1982)
This paper examines the influences of tank geometry and foundation stiffness variation on the simulated seismic structural response of a broad tank model. An empirical method for describing tank bottom plate uplift geometry is proposed which recognizes radial catenary force and foundation stiffness. Axial symmetric lift, static tilt, and dynamic shaking table tests were performed at the Univ. of California, Berkeley, Earthquake Simulator Laboratory. A structural geometric survey of a crude oil storage tank, measuring 63 ft 10 in tall by 289 ft 6 in wide, was conducted to establish a comparative base by which to evaluate the model tank eccentricities. It is concluded that the imperfections of the model tank defined by Fourier coefficients can be as much as an order of magnitude greater than those observed in the field. It is also concluded that foundation flexibility variation will significantly change the seismic response of tanks. Further, it is believed that out-of-round seismic vibration response, thought to be associated with eccentricities in tank fabrication geometry, will be less significant for large operating broad tanks resulting in lower amplitudes of asymmetric and higher order Fourier stress contribution. However, other parameters, such as uplifting, may still excite asymmetric and higher order Fourier response.
PDF 8.34 MB
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