Dynamic Load Tested Study On Progressive Collapse Resistance Of Fully Precast Concrete Frame Structures

With the rapid development of construction industrialization in China,precast concrete structure has attracted wide attention of the society.The fully assembled concrete structure has the advantages of convenient construction,quick installation and green protection,but the joint is the weak area of the entire structure.It is worth investigating whether the structure could maintain the integrity under the local damage caused by accidental loads such as explosion,impact,and fire,etc.On the basis of dynamic test of fully assembled concrete frame substructure,this paper analyzed its resistance to progressive collapse under dynamic load.Further,the finite element software ABAQUS was used to analyze the specimen,and the influence of the material strain rate effect on the dynamic collapse resistance test was studied.This article focuses on the following aspects:(1)A prototype structure of spatial frame was designed by using structure design software PKPM.And a full assembly specimen and a cast-in-place specimen were designed according to 1/2 scale.The specimen was a frame substructure containing three beam-column joints.The beam-column joints of the assembled test specimens were connected by bolt rods-cattle legs-angular steels.The two test specimens had the same longitudinal reinforcement.(2)The rapid removal test of two specimens was designed and completed.The results of the rapid removal test of the center column of the two specimens were analyzed,including structural information such as axial force response,displacement response,strain response of the steel bar,crack propagation,and failure mode.(3)According to the test results,the FE models with the same dimensions and boundary conditions as the specimens were established using ABAQUS/Explicit.The FE model was checked according to the test data before the structure was damaged,and the results were compared with the test results.(4)Based on the strain rate theory of reinforced concrete material,the dynamic test of rapid removal of column of frame substructure by Qian K was simulated by finer finite element method.The influence of failure time of corner column and lateral horizontal restraint stiffness on the dynamic response of the structure was studied.