Integrated Damping Study Of Large Scale Vertical Tank Under Near-fault Earthquake

With the rapid economic growth, China’s demand for energy is growing strongly inrecent years. Petroleum is one of the important one. Large petroleum storage tank is theimportant facility to establish national strategic oil reserve base. Large vertical tank becauseof its flammable and explosive storage media, large volume, and the complex dynamicresponse, anti-seismic and seismic isolation design studies in the tank design is particularlyimportant. This article is based on the isolation damping technology domestic and foreign andthe research of seismic response of the tank, carried out the following tasks on the basis ofprevious studies:(1) Described the characteristics of near-fault ground motions, such as rich in largeimpulse, high intensity and large ground displacement. Large vertical storage tanks due totheir own large natural period of vibration, easily resonance with longer period large impulsepredominant near-fault earthquake, particularly prone to great shaking wave height, so thatthe storage tank will happen “block top” and “deflated top” phenomenon.(2) Discussed the basic structure, operating principles and basic characteristics of someisolation base especially the variable curvature friction pendulum isolation bearing.Researched hysteretic behavior of variable curvature friction pendulum isolation bearings, andgiven the restoring force equation of variable curvature friction pendulum isolation bearing.Compared performances of different types of isolation tanks under different earthquake, andtheoretical and experimental results were compared to verify the feasibility of the theoreticalanalysis.(3)Put different isolation tanks under different near-fault earthquakes, comparativeanalysis performances of different isolation tank in large impulse near-fault earthquake to picka kind of isolation tank which is suitable for the region where vulnerable to large impulsenear-fault earthquake.(4)Put shake control devices and variable curvature friction pendulum isolation bearingsused in large vertical tank together to form an integrated damping system. Study response oflarge vertical storage tank with integrated damping system in the near-fault earthquake, andcompared with non-isolation tank and with traditional rubber bearing isolation tank. Thecomparison results showed that. The sloshing control device can reduce the sloshing waveheight of the tank under the near-fault seismic excitation. The responses of the tanks withintegrated damping system are all very small, compared with the non-seismic isolation tanks to prove the validation of sloshing control device.(5)Studied the effect of parameters of the integrated damping system to damping effectunder the near-fault earthquake excitation. And appropriate design parameters of integrateddamping system in regions where are prone to happen near-fault earthquake. The frictionsurface geometric parameters “b” selected as1.7to2.3meters is more suitable; the geometricparameters of the friction surface “d” chosen to be2.3to2.9meters is more appropriate;friction coefficient of friction surface prefer0.03to0.07is more appropriate; damping ratio ofsloshing device should not be greater than0.12; tank aspect ratio should be chosen smallerthan1.0.