考慮滑移和剪切變形的單箱雙室組合箱梁剪力滯效應(yīng)

周世軍+江瑤+吳云丹+宋剛+陳晨

摘要：為準確分析單箱雙室組合箱梁的剪力滯效應(yīng)，考慮鋼混凝土的界面滑移效應(yīng)和鋼腹板的剪切變形，針對頂?shù)装搴鸵戆宥x不同的剪力滯翹曲位移函數(shù)，基于能量變分法推導(dǎo)出單箱雙室組合箱梁剪滯效應(yīng)的控制微分方程及其閉合解。以單箱雙室組合箱梁算例為基礎(chǔ)，利用該方法分析其剪力滯效應(yīng)的規(guī)律，結(jié)果表明：在同時考慮滑移和剪切變形時，組合箱梁的撓度比初等梁理論解大，且其撓度隨界面滑移剛度的增大而減小；組合箱梁在均布荷載作用下，滑移量與荷載值近似成正比關(guān)系；在相同條件下，鋼箱梁底板的剪力滯效應(yīng)較混凝土頂板顯著。

關(guān)鍵詞：組合箱梁；剪力滯；滑移；剪切變形；單箱雙室

中圖分類號：TU441文獻標志碼：A文章編號：16744764（2017）03002008

Abstract：The effect of slip of the steelconcrete interface and shear deformation of the steel webs were considered to accurately analyze the shear lag effect of the doublecell composite box girder. The different shear lag warping displacement functions for the top and bottom plates are defined. Based on energy method， the control differential equation and the closedform solution for the doublecell composite box girder are derived. As an example， the shear lag effect of a single box doublecell composite box girder is analyzed by using proposed method. The results show that the deflection of the composite box girder when considering the slip and the shear deformation is obviously larger than that obtained by the elementary beam solution， and which will decrease with the increase of interface slip stiffness. The slip value is approximately proportional to load heavy. The effect of shear lag on bottom steels lab of the box girder is more significant than that on top concrete slab.

Keywords：composite box girder； shear lag； slip； shear deformation； doublecell box girder

鋼混凝土組合箱梁因其自重輕、抗扭剛度大、結(jié)構(gòu)延性高、適應(yīng)現(xiàn)代化施工方法等優(yōu)點在各類橋梁上部結(jié)構(gòu)中得到了廣泛應(yīng)用[1]。然而，根據(jù)眾多學(xué)者的研究發(fā)現(xiàn)，由于箱梁頂?shù)装宓募羟凶冃?，這類結(jié)構(gòu)的彎曲正應(yīng)力沿梁寬方向分布不均勻，在腹板處最大，遠離腹板逐漸減小，即“剪力滯后現(xiàn)象”。在結(jié)構(gòu)設(shè)計時，如果忽略剪力滯的影響，將會低估箱梁的撓度和應(yīng)力，導(dǎo)致結(jié)構(gòu)不安全。目前，針對剪力滯常用的分析方法有能量變分法、比擬桿法、有限單元法和有限條法等[24]。

組合箱梁是由剪力連接件將鋼箱梁和混凝土頂板緊密組合在一起共同受力，以充分發(fā)揮兩種材料性能的結(jié)構(gòu)形式。……