Dynamic Response Of Water Storage Box Structure Under Explosive Ground Motion

Compared with the natural earthquake,the explosive earthquake has the characteristics of large acceleration amplitude and short duration.The liquid storage structure is related to the storage security of strategic resources,which has attracted much attention in the national defense engineering construction.It is of great significance to improve the protection ability of the liquid storage structure by considering the influence of strong shock and ground motion on the dynamic response of the weapon explosion.In this paper,a model test of a ground type liquid storage box structure is carried out by using an explosion shock and vibration simulation platform.The dynamic response of the liquid storage structure under different water levels is studied,and the effects of ground vibration intensity and water level on the acceleration,strain and hydrodynamic pressure of the structure are analyzed.In addition,the vibration mode of the wall panel of the liquid storage structure is discussed with the theoretical method,the structural strain and hydrodynamic pressure are calculated,and the corresponding comparative analysis is made with the experimental results.Finally,the results of isolation tests are compared with those of non-isolation tests and the responses of structures before and after isolation under explosive ground motion are studied by using numerical simulation software.The main contents of this paper are as follows:(1)The explosion shock vibration model test of box structure in anhydrous state is carried out to study the acceleration and strain response at different structural positions under loading at different drop weight heights.The analysis results showed that the peak values of the acceleration and strain response of the structure increased with the increase of loading amplitude.Under the same loading,the response peak of the structure amplifies along the vertical wall height from bottom to top.(2)The strain response of structural panels under explosive ground motion can be calculated accurately by using the combined plate mode and segmental precision method.The strain response of the side panel is greatest at the middle position of the top,which is the weak position of the structure.(3)By carrying out tests on different water level conditions of the box structure,the variation law of water level change on the dynamic characteristics and dynamic response of the structure is obtained.The natural frequency of the structure decreases when the water level increases.With the increase of water storage level,the acceleration,strain and hydrodynamic pressure response of the structure are amplified more obviously due to the increase of loading strength.(4)Through the theoretical calculation of the dynamic water pressure of the structure,it is found that the dynamic water pressure of the structure wall is mainly composed of impulse pressure.Meanwhile,based on the dynamic water pressure results of the theory and test,the dynamic water pressure coefficient in the specification is modified,which is convenient to solve the dynamic water pressure of the liquid storage structure under the action of explosion and ground vibration.(5)Isolation tests are carried out on liquid storage structures without water and with water.Comparing the test results before and after isolation,it is found that the peak values of acceleration and strain response of the structure are reduced by isolation.When water is stored in the tank,the weakening effect of isolation on structural response is more obvious.The results of numerical simulation show that there is an optimal thickness of the isolation layer,and the rubber sheet has the best isolation effect at this thickness.