2002 Fiscal Year Final Research Report Summary
Elasto-plastic Earthquake Response of Reinforced Concrete Structure subjected to Bi-directional Horizontal and Vertical Motion
| Project/Area Number |
12650562
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Building structures/materials
|
|---|
| Research Institution | THE UNIVERSITY OF TOKYO |
|---|
Principal Investigator |
SHIOHARA Hitoshi Graduate School of Engineering, Associate Professor, 大学院・工学系研究科, 助教授 (50272365)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MATSUMORI Taizo Graduate School of Engineering, Research Associate, 大学院・工学系研究科, 助手 (10272361)
OTANI Shunsuke Graduate School of Engineering, Professor, 大学院・工学系研究科, 教授 (30133101)
|
|---|
| Project Period (FY) |
2000 – 2002
|
| Keywords | Reinforced Concrete / Non-linear earthquake response / Restoring force characteristic model / Strain rate / Vertical motion / Maximum earthquake response / Artificial earthquake motion / Fourier phase property |
|---|
| Research Abstract |
The objective of this project is to investigate the nonlinear earthquake responce of reinforced concrete structure subjected to bidirectional horizontal motion and vertical motion by numerical study with analytical tools. The result of this project is briefly described as follows,
A. Development of restoring force model considering sfrain rate effects
The strain rate in materials consist of the reinforcad concrete structures responding to an earthquake excitation, changes in rapid rate due to random nature of the earthquake excitation. However little attention have not been paid to the effect of strain rate. The yield point of steel changes according to the strain rate and may alter the earthquake response of structures. Hence, this study developed a new constitutive model taking into account the effect of strain rate, which is available for esast-plastic earthquake response analysis by step-by-step integration of equation of motion. Using the model, earthquake response of a single-degre
… More
e-of-freedom system was calculated. From the comparison of the earthquake response, It is revealed that in most case, the earthquake response with strain rate effect considered consumes larger total amount of energy than the model neglecting the strain rate effect, while the maximum response increase or reduce depending on each case and no consistent tendency was not observed.
B. Effect of floor vibration due to vertical motion to horizontal response
Nonlinear earthquake response of multi-storied reinforced concrete buildings were carried out with flame model with non-linear spring representing the behavior of framing member and floor slab, to investigate the effect varying axial force in column due to floor slab vibration.
C. Development of simplified procedure estimating maximum story drift response in muti-storied buildings with excitation of higher viblration modes
Nonlinear frame earthquake response analyzes were carried our to investigate the maximum story drift response in mid-to-high multi-storied buildings subjected to wide spectrum of artificial base motions with different Fourier phase properties and different target maximum acceleration response spectrum curves. The major parameters correlating to the shape of the envelope curve of maximum story drift include the relation of natural period of each mode and the shape of target shape of maximum response spectrum. (a) Provided natural period of a building is shorter than the eminent period of base excitaion, the profile of the envelope curve for maximum story drift is prominent at lower stories, while (b) natural period of a building is longer, the profile of the envelope curve is prominent at higher stories. However, not only the target maximum response spectrum but also the Fourier phase properties also showed significant effects on the profile in some case. No conclusive remarks relating to the effect of the Fourier phase characteristics was drawn by this study. Less
|
