预应力混凝土连续箱梁渡槽横向结构设计

Transverse Structure Design of Prestressed Concrete Continuous Box Girder Aqueduct

为解决预应力混凝土(PC)连续箱梁渡槽结构设计中,槽身横向受力分析不准确导致腹板、底板容易发生开裂的问题,结合南流江渡槽工程,基于框架分析法建立作用在若干个弹性支承上的PC连续箱梁渡槽横向框架力学模型,采用箱梁全截面纵向抗弯刚度计算横向框架的总支承刚度,再根据箱梁各构件的抗弯刚度进行分配,由矩阵位移法求解渡槽横向内力。研究了不同纵向位置和不均匀支承刚度对PC连续箱梁渡槽横向受力的影响,采用极限状态法建立了PC连续箱梁渡槽横向结构配筋设计方法,完成了渡槽横向结构设计。最后通过建立渡槽实体有限元模型进行对比分析,验证了弹性支承框架法对PC连续箱梁渡槽横向受力分析的适用性和准确性。

In order to solve the problem of inaccurate transverse force analysis in the structural design of prestressed concrete continuous box girder aqueduct,which leads to easy cracking of the web and bottom plate,combined with the Nanliu River Aqueduct Project,a transverse frame mechanics model of the prestressed concrete continuous box girder aqueduct acting on several elastic supports is established based on the frame analysis method.The total support stiffness of planar frame is calculated using the longitudinal flexural stiffness of the full section of box girder and then is distributed according to the flexural stiffness of each member of box girder,and the transverse internal forces of the aqueduct are solved by the matrix displacement method.The effects of different longitudinal positions and uneven support stiffness on the transverse force of prestressed concrete continuous box girder aqueduct are studied,and the design method of aqueduct transverse structure reinforcement is established based on the limit state method,so far the transverse structure design of the aqueduct is completed.The applicability and accuracy of the elastic support frame analysis method for the transverse force analysis of prestressed concrete continuous box girder aqueducts are verified by comparing the analysis with the solid finite element model.