Aseismatic Research Of Large Unanchored Oil Storage Tanks

Seismic design of large and super large storage tanks is an important part of tank design. In different countries, the codes are different from each in design calculation methods and formulas. Sometimes the tank accident happens, which seriously affects the normal production of tank farm and leads to the huge insecurity. China is more than an earthquake country and facing a new earthquake activity height. As most of the tank farms locate in the relatively frequent seismic activity area, to ensure the safety operation of these tanks during service is much important. So an in-depth study on the seismic dynamic response of large oil large storage tank with double-deck floating roof is of great significance and value.The major theoretical calculation models for large vertical cylindrical storage tanks are summarized. Using them to calculate the seismic behavior of 150000 square tank respectively. Comparing the calculation results to find out the advantages and limitations of each calculation model. Compare the existing codes of tank seismic design being used in China, the United States, Japan, and Europe; summarize the differences among them and conclude the calculation approaches for the seismic design of storage tank in each code.Experimental model of 150000 square tank designed by the similar rule of structures‘ dynamic behavior is used to do a variety of seismic tests under different working conditions and its seismic response law is obtained by data acquisition. Using the FE software ADINA to build the finite element numerical model that is similar to the test model, the numerical calculation of seismic dynamic response is done under the same condition with test model. Finally, the validity of the finite element model is verified through comparing the results of numerical calculation with the test results.Using the FE software ADINA, frequency of fluid-solid coupling of 150000 square tank is calculated and the inherent characteristic of liquid and liquid-solid coupling are analyzed. Under six different conditions, the tank bottom lift-off, liquid sloshing wave height, the stress and strain of tank wall, the acceleration and dynamic hydraulic pressure distribution of tank wall are all calculated and analyzed. The dynamic response rules of large storage tank under different level and different earthquake magnitude are found out, which can provide powerful basis and reference for the seismic design of tank.