箱拱桥荷载横向分布计算的比拟板法研究

Study on the Calculation of the Transverse Load Distribution of Box Arch Based on the Quasi-slab Method

采用三维20节点等参体元分析板拱桥拱圈横向受力行为,采用实际箱拱圈与比拟板圈的纵向抗弯、抗压刚度、横向抗弯、抗扭性能相当的原则,提出箱拱桥荷载横向分布比拟计算方法.研究表明：拱圈截面内力、挠度与荷载分布无对应关系,不能通过挠度横向分布来确定荷载横向分布;按等效原则进行箱板拱荷载横向分布计算是可行的;拱圈弯矩、轴力荷载横向分布需分别计算,一般情况下比按均匀分布确定的系数大2～3倍.

A new practical method was used to calculate lateral load distribution in box-slab arch bridge through numerical analysis based on Quasi-slab method. It is concluded that the distribution patterns of internal force, deflection and carrying-load are not relatively relevant, that is to say, it is not feasible to derive the lateral load distribution from the deflection＇ s lateral distribution. It is a practical calculation method by equivalent law for box-slab arch bridge＇ s lateral load distribution. It is necessary to calculate the bending moment＇ s lateral load distribution pattern and the axial force＇s lateral load distribution pattern respectively. The distribution factor is larger, sometimes two or three times more than that by assuming arch ring carrying uniform loads.