Study on the Seismic Performance of Different Combinations of Rubber Bearings for Continuous Beam Bridges

Table 2

Physical parameters of bearings.

Bearings	NRB-1	NRB-2	LRB-1	LRB-2	HDRB-1	HDRB-2
Height of bearings (mm)	96	112	154	234	137	187
Total thickness of rubber layer (mm)	67	82	76	125	70	110
Vertical bearing force (kN)	1258	2701	1417	3510	1360	3489
Vertical stiffness, (kN/m)	689183	1168633	806791	1382812	875000	1427000
Preyield stiffness, (kN/m)	—	—	7225	12810	4690	7510
Postyield stiffness, (kN/m)	—	—	1133	1930	1340	2150
Equivalent stiffness, (kN/m)	1700	2720	1700	2720	1700	2720
Yield force, (kN)	25	—	106	190	53	133
Shear modulus, (MPa)	1.0	1.0	1.0	1.0	1.0	1.0
Damping ratio, (%)	—	—	19.1	16.7	12	12
Limiting displacement (mm)	90	150	227	376	210	330