Research On The Application Of Connecting Wall To Seismic Reinforcement Of Existing Structures

With the improvement of seismic fortification standards and the implementation of the Regulations on the Seismic Management of Construction Projects,Seismic reinforcement of existing structures has become the mainstream direction at present.Energy dissipation and shock absorption technology has excellent shock absorption effect,and energy consumption dissipates most of the energy input from earthquakes,which is a superior reinforcement method.In order to study how to apply energy dissipation and damping technology in existing structures to improve the seismic performance of the original structure and improve the energy dissipation capacity of the structure,in this thesis,aiming at the most widely used wall connection damper,this thesis proposes to connect the damper connecting wall with the existing frame substructure by two methods: planting reinforcement connection and prefabricated steel plate bolt connection,and studies the influence and reinforcement application of connecting walls with different connection methods on the frame substructure.The main work and conclusions are:(1)The connecting wall reinforcement connection and prefabricated steel plate bolt connection are proposed,and the design process of the planting bar connection,the parameter design of the prefabricated connection component and the construction steps of the two connection methods are briefly introduced.(2)Based on the finite element software ABAQUS,a cluster of RC empty frame model and reinforcement model were established,and the hysteresis curve,skeleton curve and failure morphology of the RC empty frame finite element model and the experimental results were compared.The simulation results are in good agreement with the experimental results,and the modeling methods and parameter settings are correct and reasonable.The cohesion model was used to simulate the structural adhesive in the reinforcement structure,and the load-displacement curve of the reinforcement model and the test results were compared to verify the accuracy of the cohesion parameters.(3)Based on the verified RC empty frame model and reinforcement model,the influence of connecting walls with different connection methods on the seismic performance of the frame substructure is studied.The maximum bearing capacity of the planting bar connection and the prefabricated bolted connection is only 10.32% and 1.22% different from the cast-in-place connection,indicating that the two proposed connection methods are firm and reliable.Compared with the damage cloud,stress cloud and seismic performance of the model,the reinforcement connection changed the stress performance of the model,and entered the yield state and limit state at the earliest.The seismic performance of steel plate bolted connections is basically the same as that of cast-in-place connections.Change the layout position of the connecting wall and the size of the connecting wall,and change the order and position of the plastic hinge at the beam end.When designing reinforcement,it is necessary to consider the influence of the location and size of the connection wall arrangement.(4)Park-Ang dual-parameter damage model was used to study the damage influence of connecting walls with different connection methods on components.The degree of damage and the actual damage evolution process of different components will be different depending on the connection method.The damage degree of the frame beam is greater than that of the frame column,and the frame beam completely fails and fails at L2.The L2 section can be used as the main control section to reflect the overall damage of the component.The failure forms of beam and column members are bending failures.The damage index calculated by the Park-Ang model has a good correspondence with the damage state,indicating that the Park-Ang model can accurately evaluate the actual damage state of the component.Based on the damage analysis results and finite element simulation results,carbon fiber cloth was used to reinforce the beam and column members.After reinforcement,the ultimate bearing capacity and stiffness of the model are greatly improved.Four-sided surround reinforcement improves performance over three-sided adhesive reinforcement.The position of the plastic hinge at the beam end is transferred to the unreinforced section in the middle of the span,and the force of the component with the pasted carbon fiber cloth has a certain hysteresis,and it mainly participates in the energy consumption of the structure in the late loading stage.It is recommended that in the actual engineering reinforcement application,the connecting wall is reinforced with carbon fiber cloth when the beam and column base are connected by reinforcement.