 |
English
|
正體中文
|
简体中文
|
Items with full text/Total items : 62819/95882 (66%)
Visitors : 4006879
Online Users : 545
|
|
|
Loading...
|
Please use this identifier to cite or link to this item:
https://tkuir.lib.tku.edu.tw/dspace/handle/987654321/34536
|
| Title: | 鋼筋混凝土梁柱交會區內不連續梁主筋彎鉤配置細節之研究 |
| Other Titles: | Anchorage effects of discontinuity reinforced bar in bean-column joints |
| Authors: | 黃峻賢;Huang, Jun-xian |
| Contributors: | 淡江大學土木工程學系碩士班
廖國偉;Liao, Kuo-wei |
| Keywords: | 梁柱接頭;圍束核心;梁端塑鉸;位移載重;beam-column connection;confined core;beam plastic hinges;displacement control |
| Date: | 2009 |
| Issue Date: | 2010-01-11 05:21:31 (UTC+8) |
| Abstract: | 本研究主要探討鋼筋混凝土韌性抗彎構架中，梁主筋於梁柱接頭無法連續時，90°標準彎鈎錨定方向對梁柱接頭耐震行為之影響。根據現行ACI 318-08第21.7.5.1節及土木401-96第15.6.4.1節規定，“受拉鋼筋之90°彎鈎應置於柱或梁構材之圍束核心 ( confined core ) 中”，因此一般認定當受拉梁主筋必須於梁柱接頭中結束時，錨定用之90°彎鉤應朝向交會區中心，另外依據由梁柱交會區受剪力之壓拉桿模型也發現，在交會區受剪極限狀態下，梁主筋之90°彎鈎朝向交會區中心比朝向交會區外側，可提供交會區較佳之圍束作用。本研究共進行八組實尺寸梁柱接頭 ( 五組內柱梁柱接頭及三組外柱梁柱接頭 ) 試驗，試體之梁柱交會區剪力強度分別ACI 318-08規範與軟化壓拉桿模型建議之強度設計，對梁端施加反覆逐漸增大之位移載重進行試驗，探討梁下層主筋在梁柱接頭不連續時，其90°彎鈎往梁柱交會區核心外部錨定對梁柱接頭強度及韌性與梁端塑鉸發展之影響。
試驗結果顯示，在八組試體中，三組試體因梁主筋發生非設計允許之錨定破壞，而提前結束試驗，其餘五組試體均為試體梁於梁柱接頭處產生梁端塑鉸之破壞。此五組試體具有相同之正、負彎矩拉力鋼筋比，其彎矩強度的發展並無明顯差異，此顯示試體梁主筋90°彎鈎錨定於交會區核心外，未發現試體整體強度發展較差之現象，研判此結果與梁柱交會區剪力強度需求不高有關；但從梁柱交會區裂縫之觀察及交會區剪力變形的比較可發現梁主筋90°彎鈎往梁柱交會區外部錨定者，其交會區裂縫生成較多且交會區剪力變形較為明顯。另外統計八組試體中十三支試體梁之正、負彎矩勁度發現，若以梁彎矩包絡線在0.5 %變形內之平均勁度定義為梁之起始撓曲勁度，此勁度約僅佔梁矩形全斷面彈性勁度之22 %至32 %之間，同時由分析中也顯示，此勁度與梁拉力鋼筋比約呈線性關係。利用本研究有限之研究成果，本文也提出一梁構件於梁端產生塑鉸機構三線性簡化分析模型。
The objective of this study is to investigate the influence of the discontinuous beam flexural reinforcements, in the area of beam-column joint, on the seismic performance. According to the ACI 318-08 and Taiwan’s Concrete Engineering Design Specification and Commentary (401-96) provisions, “the 90-degree hook shall be located within the confined core of a column or of a boundary element”, indicating that 90-degree anchoring hooks should be directed to the joint core if the beam flexural bars have to be ended in this region. Also, based on the strut and tie model, when the 90-degree hooks is arranged within the core region, the confinement effect will be better with the consideration of shear force limit state, and thus have better performance. In this study, we conduct eight full size experiments (five of them are interior beam-column connections and three of them are exterior beam-column connection) to investigate the influence of the location of the 90-degree hooks’ on the performance of beam-column joints. The shear strength of the specimens are designed based on the recommendation of the ACI 318-08 code and the strut and tie model. The method of displacement control is used during each test.
Three tests fail to reach the design target due to the early anchor damaged, on the other hand, plastic hinges are found in the end of beam which is in the vicinity of the beam-column joint in the remaining five tests. Note that the development moment strengths of these five tests are close with identical positive and negative flexural reinforcement ratio, indicating that there is no apparent effect due to the different location of 90-degree hooks. The shear force requirement in the joint area is not very high could be the reason. Tests also show that more cracks and shear deformation are found in the beam-column joint area, in which the 90-degree hooks is directed to outside region of joint. In the end, we calculate the initial flexural stiffness of each beam by offset 0.5% deformation. From the calculated results, the initial stiffness is about 22-32% of the elastic stiffness. We also found that the initial stiffness is linear with the reinforcement ratio. This study also proposed a simplified tri-linear model to predict the plastic hinge mechanism in the beam area nearby the joint. |
| Appears in Collections: | [Graduate Institute & Department of Civil Engineering] Thesis
|
All items in 機構典藏 are protected by copyright, with all rights reserved.
|
