| In the last decade,major earthquakes have occurred at home and abroad.Bridges in strong earthquake zones were severely damaged,especially the piers,which are the main lateral forceresisting components,suffered from shear damage,bending damage,bending shear damage and tie beam damage,resulting in the overturning and collapse of the bridge.It is often difficult to repair after an earthquake.It is therefore of great importance to develop new types of replaceable energy dissipating elements and to establish a structural system that can quickly recover the function of the bridge after an earthquake.This paper proposes a new type of lowyielding corrugated steel web energy dissipating link beam for the transverse connection of a double-column pier,which can be replaced as an energy dissipating member after an earthquake.The research includes:(1)In this paper,six corrugated steel webs and three I-beams were designed and tested in low circumference iterations.The test results are as follows:The damage mode of the corrugated web steel beam specimens is flange buckling instability damage,while the I-beam is generally flange-end plate weld fracture.The former has a relatively full hysteresis curve and the energy dissipation capacity of the corrugated steel web specimen is better than that of the Ibeam specimen.Low-yield steel webs can obviously increase the ductility of the energy dissipating link beam,and low-yield steel web specimen LYCB17 has the most superior seismic performance.According to the force deformation characteristics of replaceable corrugated steel web beams,the design principles and shear strength calculation formulae for replaceable corrugated steel web beams are given in the article.The formulae can be used to obtain the theoretical values of the yield load capacity and the yield displacement angle of the replaceable beam,which can be compared with the test values to verify the feasibility and applicability of the proposed formulae.(2)In this paper,the finite element software ABAQUS is used to establish simplified numerical models for specimens CB17-1 and LYCB17 corrugated steel web link beams.The numerical analysis results were compared with the experimental results to verify the correctness of the simulation method.A further parametric analysis was carried out using factors such as web material,flange width to thickness ratio,web thickness,span to height ratio and waveform shape,which provide reasonable advice on the design of low yielding waveform steel web beams by giving suitable ranges of values for the parameters of low yielding waveform steel web beams.(3)Design of a low yielding waveform steel web energy dissipating continuous beam double column pier structural system,proposing a structural form with replaceable crossbeam after earthquake.The finite element software ABAQUS was used to establish three kinds of 3D solid finite element models of bridge piers,namely double-column piers without crossbeams(referred to as test piece DCP),double-column piers with reinforced concrete crossbeams(referred to as test piece RCB-DCP)and double-column piers with low yielding waveform steel webs and energy dissipating link beams(referred to as test piece LYCB-DCP).The numerical results obtained from the above three pier models loaded repeatedly at low circumference show that the low yielding waveform steel webs with energy dissipating link beams provide a very good seismic performance compared to the traditional two-column pier system. |
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