Investigation on ultimate behavior of rubber bearings and their seismic verification method considering the interaction of piers and a superstructure under bi-directional seismic excitations

2014 Fiscal Year Final Research Report

• Project/Area Number: 25820207
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Structural engineering/Earthquake engineering/Maintenance management engineering
• Research Institution: Nagoya Institute of Technology
• Principal Investigator: EBISAWA Takemasa 名古屋工業大学, 工学(系)研究科(研究院), 助教 (90332709)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 耐震構造 / 積層ゴム支承 / 破断試験 / 振動台実験 / 連続高架橋

Outline of Final Research Achievements

During the bi-directional shake table test, the rubber bearings installed in a scaled 2-span elevated-girder bridge model exhibited rotational deformations and the variation of axial forces that are ignored in the current seismic design. Due to these axial forces and rotational deformations, the local stress and local strains in the rubber bearings may exceed the allowable limits specified by the current design code. Then, bi-directional cyclic loading test was conducted on rubber bearings by newly developed loading system. By making use of the test data obtained from the above tests, a FE model with a nonlinear elastic constitutive relation was presented. This model appropriately expresses the shear deformation of the bearings. However, there is still a room to improve the model by considering the hysteretic behavior caused by the tensile stresses. Finally, it was observed by the shear rupture test that the load carrying capacity of the bearings decreases under tensile axial force.

Free Research Field

構造工学