Page 218 - 捷運工程叢書 精進版 - 32 捷運高架橋梁結構設計與施工
P. 218
臺北市政府捷運工程局
P = Fjcosθ = 480.4×cos10
= 473.12 Ton
△ = PL/EA
=(473.12×1,000×8.45×100)/(26,936×204,000)
-4
= 7.26×10 cm
-4
帽梁長(m) 彈性縮短 ×10 cm 預拱量△(cm)
8.45 7.24 0.02035
8.55 7.34 0.02098
8.65 7.42 0.02233
8.75 7.50 0.02298
8.85 7.60 0.02300
8.95 7.68 0.02398
△
圖 9-4-11 帽梁預拱示意圖
(4) 扣除摩擦損失外之預力損失
△ f = SH+ES+CR +CR .....(Ref. to AASHTO 9.16.2.1, Total loss)
S
C
S
△ f 扣除摩擦損失外之預力總損失,kgf/ cm 2
S
2
SH 混凝土乾縮損失,kgf/cm (loss due to concrete shrinkage)
2
ES 混凝土彈性縮短損失,kgf/cm (loss due to concrete shortening)
2
CR 混凝土潛變損失,kgf/cm (loss due to creep of concrete)
C
2
CR 鋼材鬆弛縮短損失,kgf/cm (loss due to relaxation of prestreesing steel)
S
2
SH = 956-8.44RH, kgf/cm ;RH= 相對濕度百分比 = 80
2
ES = 0.5×(Es/Ecs)×fcir, kgf/ cm ;Es = 1.97×106kgf/cm 2
1.5
ECs = 0.1368W ×f' ci 0.5
CRc = 12f -7f , kgf/cm 2
cir
cds
f = 預力傳遞後由預力及梁淨重作用時,在預力鋼材重心處之混凝土應力
cir
f = 除預力梁之外之所有靜重作用時,在預力鋼材重心處之混凝土應力
cds
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