Energy Consumption Mechanism And Design Method Of Prefabricated Steel Frame Pier With Energy Dissipation Shell Plates

Earthquakes are one of the most significant risk factors that should be considered during the service period of engineering structures.Although the performance-based seismic design at this stage can meet the fortification requirements of structures that cannot be shaken by large earthquakes,large residual deformation and serious damage often occur after a strong earthquake,and the result is difficult to repair or serious due to long repair time Affects the emergency response and normal use of the disaster,so the seismic design of the structure is changed from the prevention of the collapse of the structure to the restoration of the function of the structure.Bridge pier is the main load-bearing component of the bridge,and its failure will cause the complete loss of function of the bridge after the earthquake.Therefore,the bridge pier plays a vital role in the overall seismic performance of the bridge.Compared with the traditional reinforced concrete pier with disadvantages such as self-heavy weight and poor ductility,the steel pier has good strength and seismic resistance.During earthquakes,the main failure form of steel bridge piers is local buckling of the top and bottom of the piers.This paper introduces the structural recoverable function and the replaceable energy-consuming components of the structure into a steel frame bridge pier after the earthquake: external low-yield energy-consuming shell plates are placed outside the plastic hinge area of the pier to protect the main structure of the pier column,and the external energy-consuming shell plates are prone to earthquake Repair or replace.A numerical simulation method was used to compare the hysteresis curve,energy dissipation capacity,and equivalent viscous damping ratio of a fabricated steel frame bridge pier and a fabricated steel frame bridge pier with energy dissipating shell plates under horizontal reciprocating loads and constant vertical loads,stiffness and strength.Based on this,the effects of energyconsuming shell and plate parameters(such as material yield stress,installation height,and thickness)and pier parameters(such as axial compression ratio,slenderness ratio,and steel plate widththickness ratio)on the seismic performance of fabricated steel frame bridge piers are discussed.Influence and its laws,and based on the results of parameter sensitivity analysis,the fitting empirical formulas for the yield displacement of energy-consuming shell plates and the parameters of energyconsuming shell plates and pier columns are designed,and the pier columns and The geometric parameters of the energy-consuming shell plate,a functional recoverable design method based on an assembled steel frame bridge pier with an energy-consuming shell plate is established for practical engineering seismic design applications.The results show that the seismic performance of prefabricated steel frame bridge piers with energy dissipative shell plates is better than that of prefabricated steel frame piers,and the energy dissipative shell plates yield before the pier columns,which can effectively protect the main body of the pier columns from earthquake damage;The impact of material strength on seismic performance is almost negligible;the larger the installation height and thickness of the energy-consuming shell plate,the better the seismic performance of hysteretic performance,stiffness,strength,and equivalent viscous damping ratio,but the excessive installation height does not promote Effect,at the same time,the thickness of the energy consuming shell plate is too large to reduce the equivalent viscous damping ratio and affect the energy consumption capacity;as the pier column axial compression ratio,slenderness ratio and steel plate width-to-thickness ratio decrease,the bearing capacity and hysteresis curve package The seismic performance such as the enveloping area and the maximum horizontal force is also enhanced;considering the energy-consuming shell plate parameters(installation height and thickness)and pier parameters(axial compression ratio n and steel plate width-thickness ratio)and yield deformation tolerance,the correlation coefficient R between the fitting empirical formula of the 1st Opt regression of the application software and the numerical simulation data is 0.965,which has a high calculation accuracy;the pier column and the energy consumption are designed based on the numerical model and the fitting empirical formula.Couple of shell plates The parameters can be used to establish a functionally recoverable design method for an assembled steel frame bridge pier with an energy-consuming shell plate,which is beneficial to the practical engineering seismic design application.