Research On Seismic Performance And Simplified Analysis Method Of Semi-underground Reservoir Structures

As a special underground structure,the liquid storage tank may have various seismic damages under the action of earthquakes,including damage to auxiliary structures in the tank,erosion damage,local instability,material damage,and wall damage,etc.,and once it has occurred Disasters will cause great harm to people’s lives and property safety.Due to the particularity of its location and structure,scholars from various countries have seldom studied its response to earthquakes.Therefore,it is of great significance to analyze the seismic performance of the reservoir.In this paper,combined with engineering practice,the finite element analysis software FINAL was used to analyze the seismic response of a four-and-a-half-story underground reinforced concrete reservoir.The main research contents were as follows:(1)The calculation model was established,and the calculation model was established with FINAL finite element software according to the actual size of the pool.Used suitable elements to simulate the pool wall and the beams and columns in it,adopted appropriate methods to deal with variable cross-section pool walls,deal with issues such as steel reinforcement according to certain methods,and adopted appropriate material constitutives according to engineering data.(2)The complicated boundary conditions of the structure were processed,and then the liquefaction judgment of the foundation soil and the calculation of the negative friction force of the pile group foundation were carried out respectively.The surrounding soil below the ground of the reservoir and the pile group foundation below the bottom plate were treated with membrane elements.The foundation reaction coefficients of the side plates and the floor were calculated through calculations,and the horizontal foundation reaction coefficients and tangential foundation reaction coefficients of the membrane elements were given..(3)Multi-condition analysis,based on the finite element model,considered dynamic water pressure,dynamic earth pressure,inertial force,hydrostatic pressure,static soil pressure,dead weight,equipment load,and measures for empty water and full water under Level 1 ground motions,and Level 2 Multi-condition analysis was carried out in different directions of +x,-x,+y,-y full of water under ground motion,and the maximum shear stress of the structure,the tensile stress of steel bar and the maximum compressive stress of concrete under Level 1 earthquake were obtained,and the difference was found The most dangerous position of the structure under working conditions.For Level 2 ground motions,the ultimate state design method was used to check the seismic performance of the structure’s failure mode,and analyzed the most unfavorable seismic response results corresponding to each working condition.(4)A simplified finite element model of the structure was established,and the model was calculated using the quasi-static method and the time history analysis method under the same boundary conditions and loading conditions under the condition of meeting the calculation accuracy requirements,and the calculation results of the two analysis methods were obtained.A correction factor of 1.37 was proposed so that the calculation results of the two seismic methods could be converted.The correction factor was used to convert the calculation results of the quasi-static seismic degree method to the calculation results of the simplified time history analysis method.Revised the results of the calculations of the two methods,and maked use of the advantages of the two methods to analyze the seismic performance of the structure,and provided ideas for the seismic performance analysis of underground pools in our country.