Study On Explosion Response Of Prefabricated Reinforced Concrete Structures Connected By Grouting Sleeve

With the rapid development of urbanization and the development requirements of building industrialization,our government has vigorously promoted the application of prefabricated buildings in recent years.Grouting sleeve splicing is the main connection form in prefabricated structural members.Its connection characteristics may cause potential safety hazards at the connection parts.Once the connection part of a prefabricated structure is damaged,the building may partially or global collapse.Recently,explosion accidents frequently occur due to terrorist attacks,improper use and disposal flammable and explosive chemicals and gas in production and life.The strong blast wave caused serious damage in the joints of prefabricated structural members and the whole structure.At present,the study on the performance of prefabricated structures mainly focuses on the seismic evaluation of the connection parts.There are relatively few studies on the antiknock performance.This paper uses the finite element analysis software ANSYS/LS-DYNA to analyze the explosive response and failure patt ern of prefabricated reinforced concrete shear wall connected by grouting sleeve and prefabricated frame-shear wall connected by grouting sleeve.The main research results and work are as follows:(1)The material constitutive and corresponding algorithm w ere selected.The finite element model of reinforcing concrete slab under explosive impact load was established.The simulation results were compared with the experimental results under the same conditions,which verified the effectiveness of the finite el ement modeling method and the selection of relevant parameters.(2)The finite element models of cast-in-place reinforced concrete shear wall and prefabricated reinforced concrete shear wall connected by grouting sleeve was established.The simulation of the grouting sleeve and the contact of grouting layer interface was introduced.Based on the comparative analysis of the dynamic responses and failure modes of two kinds of shear walls under the explosive impact lo ad,the antiknock performance of prefabricated reinforced concrete shear wall connected by grouting sleeve was evaluated.At the same time,the parameters that affected the antiknock performance of the prefabricated reinforced concrete shear wall connected by grouting sleeve were analyzed.The results show that increasing the thickness of the wall,moving the explosive away from the mid-position of the prefabricated reinforced concrete shear wall,increasing the compressive strength of the concrete and adopting the fixed support restraints at the end of the wall can reduce the peak displacement in the middle of the prefabricated reinforced concrete shear wall and improves its antiknock performance.(3)The finite element model of two-story cast-in-place frame shear wall and prefabricated frame-shear wall connected by grouting sleeve were established.The dynamic response and failure process when the explosive was placed in the center of the first-layer frame,the center of the second-layer frame,0.5 m from the front wall of the shear wall center and 0.5 m from the right column center from the column surface were analyzed and compared.The antiknock performance of prefabricated frame-shear wall connected by grouting sleeve was evaluated.According to the simulation analysis in this thesis,the antiknock performance of prefabricated reinforced concrete shear wall connected by grouting sleeve is poor.After the contact of grouting layer interface is broken under the blast load,the concrete of grouting layer is easy to failure and its reinforcement is eas y to yield fracture.The stress wave in the component can't be effectively transmitted.Brittle failure is easy to occur in the grouting layer area.The prefabricated frame-shear wall connected by grouting sleeve has poor integrality.The blast load is easy to gather in the weak part of the structure,which makes the deformation of the structure concentrated deformation and easy to cause local concentrated serious damage of the structure.