单点支承单箱多室连续梁的空间受力分析

Space Force Analysis of Single Point Bearing & Single Box Multi-Cell Continuous Beam

本文对支承条件、桥型各异的3座单箱多室连续梁桥，采用有限元平面杆系程序和有限元空间架格程序分别加以计算，结果发现单箱多室连续梁桥内外肋纵向内力的强度沿截面分布很不均匀；且由于单点支承或相邻支承条件的不同，截面横向发生的沉陷较大，其纵向内力出现重分布。梁纵向内力与通常的平面杆系计算结果有较大的出入，误差之大，若仅采用杆系程序计算结果，再提高10％的“安全”系数，一方面造成材料不必要的浪费，另一方面将导致设计不安全。

This paper calculates three single box and multi-cell continuous girder bridges with different bearing conditions and bridge types by using finite element plane member system program and finite element space beam grillage program. respectively. It is finally found that the longitudinal internal force strength of internal and external ribs in single box and multi-cell continuous girder bridges have been unevenly distributed along cross section. At the same time .because the different signal point bearing or different adjacent bearing condition. the settlement of cross section in transverse direction is larger and the longitudinal internal force is re- distributed. The longitudinal intermal force of the beams has larger different with the calculation result normal plane member system. If using the calculation results of member system program only. 10% 'safety 'coefficient should be increased . on the one hand, it will cause un-necessary material waste .on the other hand.it will lead to the unsafety of design.