1998 Fiscal Year Final Research Report Summary
Ultimate Seismic Behavior of Steel Bridge Pier Base-to-Footing Connections and Their Seismic Design
| Project/Area Number |
09555144
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
構造工学・地震工学
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
GOTO Yoshiaki Nagoya Institute of Technology, Professor, 工学部, 教授 (90144188)
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| Co-Investigator(Kenkyū-buntansha) |
TAJIMA Hitoshi Metropolitan Highway Corporation, Construction Department, Specification Group L, 工務部, 設計基準班長
IWAMOTO Masami Nagoya Institute of Technology, Faculty of Engineering, Lecturer, 工学部, 講師 (60232716)
OBATA Makoto Nagoya Institute of Technology, Faculty of Engineering, Associate Professor, 工学部, 助教授 (30194624)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Anchor bolt / seismic design / anchorage / steel bridge peer / component method |
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| Research Abstract |
The hysteretic behavior of pier base-to-footing connections is examined by carrying out cyclic loading tests on pier base models. Based on this result, hysteretic models for pier base, referred to as "semi-empirical model" and "simplified composite model", are proposed. The semi-empirical model consists of an analytically obtained skeleton curve and experimentally determined hysteresis loops. These hysteretic models are implemented in nonlinear dynamic analysis for steel piers. The validity of the proposed hysteretic pier base models is confirmed by the fact that the nonlinear dynamic analysis with the pier base models can simulate the actual damage patterns of piers and anchor bolts observed in the Kobe earthquake. By using the semi-empirical pier base model, we analytically investigate the effect of pier base restraint on the overall ultimate behavior of steel bridge piers under severe earthquake motions. As a result, it is observed that the strong pier base restraint increases the damage to steel piers, whilst week restraint decreases the damage to piers but increases the damage to anchor bolts. There seems to be an optimum magnitude of pier base restraint that minimizes the maximum response displacements and residual displacements. For the design purpose, we discuss a necessary pier base moment capacity where the damage to pier base will no exceed the damage to steel pier. Furthermore, we examine the applicability of the static analysis based on the Newmark's energy conservation principle as an alternative to the nonlinear dynamic analysis.
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