Elephant's foot phenomenon in liquid storage tanks

Conference · Sat Jan 01 04:00:00 UTC 1983 · Am. Soc. Mech. Eng., Pressure Vessels Piping Div., (Tech. Rep.) PVP; (United States)

OSTI ID:5452241

Chen, C Q

This paper presents a method for analyzing the seismic response of a flat bottomed cylindrical liquid storage tank to vertical earthquake excitation. Here, vertical earthquake acceleration is considered to correspond to an increase in the density of a stored liquid. Taking into account the vertical and horizontal earthquake loads, hydrostatic pressure, and considering restrictive moment and shear forces at shell-bottom welded joint, the author has calculated circumferential and longitudinal stresses. These are combined to more accurately approximate the stresses at the base shell course. The calculated result closely conforms to the actual damage, termed ''elephant's foot,'' observed in the fuel storage tanks damaged in the Tangshan earthquake. This result shows that the ''elephant's foot'' phenomenon is not caused by buckling of the tank shell due to longitudinal compressive stresses resulting from horizontal earthquake acceleration, but rather by the combined stresses in the base shell course of the storage tank exceeding the yield strength of the shell course material. The effect due to vertical earthquake load is more than the effect from the horizontal load. Finally, some earthquake resistant methods to prevent the ''elephant's foot'' phenomenon are suggested by the author.

• Research Organization: Pipeline and Design and Research Institute, Petroleum Ministry, Langfang
• OSTI ID: 5452241
• Report Number(s): CONF-830607-
• Conference Information: Journal Name: Am. Soc. Mech. Eng., Pressure Vessels Piping Div., (Tech. Rep.) PVP; (United States) Journal Volume: PVP-VOL.77
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
024000* -- Petroleum-- Storage-- (-1989)
CONFIGURATION
CONTAINERS
CYLINDRICAL CONFIGURATION
DENSITY
EARTHQUAKES
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUELS
HYDROSTATICS
LIQUIDS
LOADING
MATERIALS HANDLING
MECHANICAL PROPERTIES
PETROLEUM
PHYSICAL PROPERTIES
SEISMIC EFFECTS
SEISMIC EVENTS
SHEAR
SHELLS
STORAGE FACILITIES
STRESSES
TANKS
YIELD STRENGTH