Mechanical properties and seismic performance of prefabricated thin-walled piers connected by grouted sleeves
In order to study the mechanical properties of prefabricated thin-walled piers connected by grouted sleeves and the overall seismic performance of the bridge,firstly,the damage morphology characteristics of a group of ordinary cast-in-place thin-walled piers and prefabricated thin-walled piers connected by grouted sleeves were investigated through the proposed quasi-static test,and the differences in the skeleton curves and hysteresis curves between the two types of piers were analysed by comparing and contrasting them.Then,based on ABAQUS platform and the test data of this paper,the numerical simulation of the grouted sleeve connected thin-walled piers is carried out.On this basis,a three-span continuous box girder bridge is selected as an example,the multi-scale finite element dynamic analysis model of the whole bridge is established,and 100 ground are selected for the nonlinear time-history analysis,and the differences in the time-history response of the bridge components and hysteresis curves of the bridges set up with different piers are studied.Finally,the seismic fragility curves of different members were established to analyse the damage characteristics of each member of two types of bridges.The test results show that the damage form of prefabricated thin-walled pier is bending and shear damage,the concrete in the sleeve area is intact,the plastic hinge region is transferred to above the sleeve cross-section,the overall ultimate bearing capacity is slightly increased,the hysteresis curve shape is relatively full,with good plastic deformation capacity,and the hysteresis performance of ordinary cast-in-place thin-walled piers is basically the same.The model can simulate the overall mechanical properties of prefabricated thin-walled piers.The time-history fluctuations of prefabricated thin-walled piers mainly occur in the middle period of earthquakes.The difference in maximum displacement and internal force response between the two types of bridge piers is about 5%and 10%,and the bearing response is less affected compared to the bridge pier.Prefabricated thin-walled pier bearings and blocks are easily damaged components,and abutment bearings and blocks are more easily damaged than bridge piers.Prefabricated thin-walled piers are more easily damaged than ordinary cast-in-place thin-walled piers,but the difference is small.Prefabricated bridge piers can basically achieve the design principle of equivalent cast-in-place.