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Experimental Study on Seismic Performance of Laminated-Rubber Bearings as Structural Fuses
Department of Bridge Engineering, Tongji UniversityNailiang Xiang
The 7th Kwang-Hua Forum on Innovations and Implementations
in Earthquake Engineering Research9-11 December 2016, Shanghai, China
Introduction1
Quasi-static testing2
Shake-table testing3
Conclusions4
1 Introduction
Introduction
Ø Support length in longitudinal direction
Ø Concrete shear keys in transverse direction
Ø Without any connection except friction
Ø Directly placed between the superstructure and the substructure
Typical installation details of laminated-rubber bearings in China
Introduction
Sliding of laminated rubber
bearings
Concrete shear keys failure
Expansion joints damage
Ø 2008 Wenchuan earthquake
Ø Small to medium-span bridges
Ø Damage investigation
Ø Typical earthquake damages
Introduction
Bridge span collapse due to inadequate pier-girder support
length
Detail A Detail B
Introduction
Sliding of laminated rubber
bearings
Excessive girder displacements
Damage of shear keys, abutments, expansion joints due to pounding
Minor damage of substructures
Excessive pier-girder relative displacements
Bridge span collapse due to
inadequate support length
Typical Damage Process of Highway Bridges in Wenchuan Earthquake
2 Quasi-static testing
9
Quasi-static testing
Vertical Loading ArmTop Steel Plate
Bearing Specimen
Displacement Gage
Bottom Steel PlateHorizontal Loading Arm
Rollers
Testing apparatus Testing setup
Cyclic loading protocol Testing process
10
Quasi-static testing
Monotonic force-displacement curves Cyclic force-displacement curves
11
Quasi-static testing
Effect of normal pressure and loading velocity on the friction coefficients of bearings
3 Shake-table testing
13
Shake-table testing
Setup of a quarter-scale bridge model Installation of laminated-rubber bearings
A Northridge earthquake wave A response spectrum-compatible artificial wave
14
Shake-table testing
Hysteretic force-displacement curves of laminated-rubber bearings subjected to Northridge wave
15
Shake-table testing
Hysteretic force-displacement curves of laminated-rubber bearings subjected to artificial wave
16
Shake-table testing
Peak measured strains in longitudinal steel bars in piers
4 Conclusions
18
Conclusions
1
4
2
3
The coefficient of friction is inversely related to normal pressure, while positively related to velocity;
The sliding of laminated-rubber bearings can act as fuses, dissipating large amounts of earthquake energy and providing an isolated response for substructures;
Design strategy considering the sliding of laminated-rubber bearings is simple and cost-effective, compared with some conventional isolation bearings;
Future research will mainly focus on the calibration of the proposed design strategy.
Thanks for your attention!
Department of Bridge Engineering, Tongji UniversityNailiang Xiang
The 7th Kwang-Hua Forum on Innovations and Implementations
in Earthquake Engineering Research9-11 December 2016, Shanghai, China
