Test and Analysis for Strength and Flexural Rigidity of RC Arches

• Main Authors: Li, How-Way, 李豪偉
• Other Authors: Liou Yuh-Wehn, Sheu Shyong-Maw
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/11500918248233049213

碩士 === 國立成功大學 === 建築(工程)學系 === 85 === Copyright (c) 1990, Microsoft Corp 本文研究之目的在探討具足 夠的吊筋(Hanger)的RC拱，受面內垂直載重作用下，企圖尋求其撓曲強度 與剛度的預測、環狀裂縫載重預測、抗剪強度及韌性之檢討。本文共試 驗9支RC拱足尺試體。試體包含不同的主筋配筋比、箍(吊)筋量、間距等 。試體尺寸內徑110cm、外徑150cm、拱深40cm、拱寬25cm。試驗加載方式 採集中載重一週次加載。分析時以RC理論及試驗的行為作基礎，分析RC拱 受垂直載重後的力學行為，並建立載重-位移曲線之預測模式。分析值與 試驗值的比較亦考量陳蔚文碩論試驗中部份試體。 本文獲得的結論： 1.應變以雙曲線分佈模擬，積分應力後求得撓曲強度，可合理地預測RC拱 撓曲開裂載重 、屈服載重及極限載重。 2.RC拱撓曲開裂 後有效剛度，以Mcr、Mmax、Ig、Icr及ρ為變數之經驗公式來模擬，計 算後與試驗值相近。 3.RC拱剪力筋抗 剪強度，以修正箍筋間距=Rav(απ/180)及有效拱深d代入直梁抗剪強 度計算，可合理預測。 4.RC拱的全程曲線預測，與試驗曲線大致相符。 5.RC拱拉力配筋比<0.5且壓力配筋比> 0.3時，其韌度比大於2.5。 6.箍筋角不大於6度，且箍筋量足夠時，可代替吊筋。 Copyright (c) 1990, Microsoft Corp The purpose of this paper is to study behaviors of RC arch with enough hanger under vertical load applied. There are 9 specimens of full scale RC arches ( 150 cm exterior radius, 110 cm interior radius,40 cm depth and 25 cm width )tested by vertical load of one cycle in this paper, which include differentratio of main bar. Base on the RC theory and the behavior of test process,the analytic outcomes provide : the variation of flexural rigidity ; theprediction of circular- crack load ; the sheer strength , and finally establishthe model of load-deflection curve. Parts of specimens in the W. W. Chen' spaper are considered when comparing the analytic value with the tested value. The conclusions of this paper are as follows : 1. When the strain is imitated with hyperbolic distribution and the stress is integrated, the bending strength can be predicted rationally . 2. The prediction of effective stiffness of RC arch is imitated with the experimental formulas whose variables include Mcr、 Mmax、Ig、Icr and ρ. 3. It is reasonable to modify hoop spacing =Rav(απ/180) and effective arch depth in the calculation of sheer steel against sheer. 4. All predicted load-deflection curves compared with experimental tests show reasonable results. 5. If the hoop spacing angle is less than and the hoop quantity is sufficient, the hanger can be substituted for the hoop. 6. When ρis <0.5ρb andρ' is > 0.3ρin RC arch, the ductility ratio is>2.5 .