Study On Seismic Bearing Capacity Analysis Of Brick Masonry Spandrel-Substructure

Masonry structure still exists for a long time in the process of urbanization in China Due to its own limitations of Material properties,poor seismic performance cause so heavy damage in previous earthquakes.It has been proved that the seismic performance,ductility and energy dissipation of the failure mode of masonry structure spandrels are better than other failure modes,and the researches in this field are abundant.However,the theoretical study on the calculation of seismic bearing capacity of the masonry structure spandrels is still insufficient.Therefore,with the theoretical analysis and numerical simulation,this paper focuses on the design method of seismic bearing capacity of spandrels.This study is based on the reasonable failure mode of masonry structure spandrels,analysis of different failure modes of spandrels under reasonable failure mode by ABAQUS finite element simulation.In order to provide the basis for the calculation of seismic bearing capacity of different failure modes of spandrelsThe main contents are as follows:(1)In the finite element simulation,a model consistent with the test conditions is established,by comparing the simulation results with the test results,the correctness of the finite element modeling is verified.At the same time,the seismic performance of masonry specimens under different failure modes is analyzed;(2)In view of the reasonable failure mode of the masonry spandrels,the influence of different factors on the different failure modes of masonry spandrels is analyzed by the finite element simulation,and through the parameter deduction to analysis the influence of the different stiffness ratio and the different span-height ratio on the peak load of masonry structure spandrels.(3)The corresponding calculation formulas of seismic bearing capacity are put forward for bending failure and shear failure of the spandrels,and verify it according to relevant tests and literatures.The results show that:(1)it is feasible to use finite element simulation for different failure modes of the masonry spandrels,and through the analysis of the seismic performance of the spandrel-substructure specimens under different failure modes,it is verified again that the failure mode of masonry structure spandrels is reasonable;(2)the stiffness ratio between spandrel and piers,the span-depth ratio of spandrels,the axial force of spandrels and the vertical force of piers have certain influence on different failure modes of masonry spandrels.Especially the axial force of spandrels,when the relative stiffness ratio ?=1.0,the span-height ratio ?<1.0,with the increase of axial force,the bending sign of the spandrels is less obvious,and the failure mode is shear failure;when??1.0 with the increase of axial force,the failure of spandrels tends to change from bending to shear failure,when the span-height ratio is large,the smaller the axial force is,the bending failure of spandrels will occur;(3)The equivalent tensile strength caused by block interlocking should be considered in the calculation of flexural seismic bearing capacity of the masonry structure spandrels,and the favorable influence of the axial force on the bearing capacity is taken into account.The stiffness ratio and span-height ratio have a great influence on the shear seismic bearing capacity,which should be considered in the bearing capacity calculation.According to the different failure modes of spandrels,the calculation formula of the seismic bearing capacity is put forward,and the rationality of the formula is verified by experiments and literatures.