Seismic Shaking Table Test Of Liquid Storage Tank Considering Pile-soil Interaction

With the development of the national oil industry and the implementation of the national oil strategic reserve,the role of petroleum storage tanks is increasingly important.When oil tanks encounters earthquakes,whether it is structural damage or the resulting secondary disaster,it will pose a serious threat to human life and property.In the current tank design,the foundation is regarded as rigid and the pile-soil interaction is ignored.But the actual projects show that the pile-soil interaction has a greater impact on the tank.Based on this consideration,and the requirements of the research fund project,a series of studies on the pile-soil-tank system have been carried out,including shaking table test and numerical simulation.According to the research of scholars at home and abroad,a shaking table test was carried out for the pile-soil-tank system.The variation law of the acceleration along the height direction of the soil,the amplification effect of the structural system,and the influence of long and short period seismic waves on the shaking wave height of the stored liquid were studied.The ADINA software was used to simulate the test model.Based on this,the ADINA software was used to conduct numerical simulation analysis of the 100,000-square-ton large oil storage tank-pile-soil system.The specific research contents are as follows:1.The first phase shaking table test(Pile-soil-concentration test): the first stage shaking table test follows the similarity theory and designs the shaking table model test according to the laboratory's existing equipment.The upper tank is considered as a single-mass system and is expressed in terms of concentration.The pile uses aluminum alloy pipe piles and the soil uses local silty clay.The test results show that the ground surface acceleration of the soil is amplified.When the input acceleration peak value is small,the acceleration magnification of each point in the soil layer gradually increases along the height direction of the soil.And when the input acceleration peak increases,the acceleration magnification of each point in the soil decreases first and then increases along the height of the soil.The ground surface acceleration magnification is greater than the pile head acceleration magnification.2.Second stage shaking table test(Pile-soil-organic glass tank test): The second phase shaking table test relaxed the similarity relationship and replaced the upper concentration force with the storage tank.There are two types of tanks.The tank diameter is 0.9m and the ratio of height to diameter is 0.88 and 1.52,respectively.In order to study the effects of long-and-short-cycle seismic waves on the wave height of the reservoir,some seismic waves are added and all the seismic waves are divided into general ground motions and long-period ground motions.The test results show that the overall structure amplification effect is increased along the height of the structure.And with the increase of the ground motion input peak,the magnification of the structural system decreases.When the peak input of the ground motion is small,the acceleration of the upper tank gradually increases along the tank height.When the input peak increases,the tank wall acceleration decreases first and then increases.In all operating conditions,the maximum acceleration of the coupling between the tank and the liquid is obvious.In general ground motion,with the increase of the input acceleration peak,the shaking wave height of the stored liquid increases approximately linearly.Long-term ground motion is nonlinear.Under long-term ground motion,the shaking wave height of the reservoir is greater than that of general ground motion.So for tanks,long-term ground motion can't be ignored.Different types of tanks produce different wave heights from the liquid.The high-level tanks produce a slightly higher wave height than liquid tanks.Under long-and-short-term ground motion excitation,this law is exhibited.3.Numerical simulation analysis: The numerical simulation analysis of the tank system with H = 0.8m in the above second-stage shaking table test was performed,and the simulation and the test were mutually verified.Based on this,a 100,000-square-ton large-scale oil storage tank-pile-soil system model was built,and three-way and one-way ground motions were input for analysis.The test results show that: Compared with rigid foundations,considering the interaction between piles and soils,the base shear,overturning moment,and hydrodynamic pressure of storage tanks decrease,but the wave height increases.The soft soil layer has a significant weakening effect on horizontal ground motion and no attenuation on vertical ground motion.When the three-way ground motion is input,the base shear force of the tank,the overturning moment,the hydrodynamic pressure,the effective stress of the tank wall,the hydrodynamic pressure,and the shaking wave height of the stored liquid are all greater than when the unidirectional ground motion is input.For soil acceleration magnification,the overall change trend is the same,but the three-way ground motion input is slightly greater than the surface acceleration.