单拱面预应力混凝土系杆拱桥极限承载力分析

ANALYSIS OF THE ULTMATE LOAD OF ON-PLANE PRESTRESSED CONCRETE BOX GIRDER TIED ARCH BRIDGE

本文将系杆拱桥的拱肋离散为空间圆弧梁单元，基于拖带圆柱坐标推导格林应变张量，用平截面假定及三次插值函数描述圆弧梁单元位移模式，采用加权残值配点法消除剪力和薄膜力闭锁；现吊杆为二力杆单元。对于多室箱形梁系杆离散为梁段单元，考虑箱形梁翘曲、畸变、横向弯曲等。基于连续介质力学U．L．列式法建立系杆拱桥的平衡方程并考虑材料的非线性。根据分析模型编制了相应的计算程序，计算结果与实验结果一致，同时分析了单拱面系杆拱桥极限承载力的影响因素，并计算了一座实桥的极限承载力。

Arch structure is discretized into space curved beam elements. The initial and deformed configuration are described by the cylindrical co-ordinate system. The Green strain tensor is formed. The displacement components of the curved element are interpolated using cubic polynomials. It is assumed the plane section of the curved beams remains Plane during deformation, but not necessarily perpendicular to the neutral axis The membrane locking and shear locking are eliminated by the Method of Weighted Residuals. Thin-walled multicell box girder is discretized into space beam elements. The displacement field of the beam elements is constructed, based on the assumption of plane section and Cartesian co-ordinate system. Bending, torsion, torsion warping, cross-section distortion distortional warping and shear lag effect of the box girder are taken into account in the present analysis. A computer Program has been written. Good agreement between the computed results and the experiment results is achieved. The ultimate load of an engineering case is obtained.