简支下承式桁梁结合梁的模型试验

设计制作一个4节间下承式桁梁结合梁模型。分3个阶段10种荷载工况进行模型的力学性能试验,研究简支下承式钢桁结合梁桥的受力性能。结果表明:主桁的挠度和内力可以按平面桁架计算;桥面系中存在起控制作用的横梁,设计中应特别关注;纵梁主要受轴向拉伸和竖向弯曲作用,最大拉应力出现在每节间正中截面的下翼缘,内侧和外侧无多大区别;混凝土板的受力状态以竖向荷载作用下的弯曲为主;竖向偏载和水平偏载都不控制设计。

Model Test for Through Truss Composite Beam with Simple Support

A through truss composite beam model with 4 panels is designed and made. The mechanical property test of the model covering 3 stages under 10 load conditions is carried out to study the loading property of through truss composite beam with simple support. Test results show that the deflection and the internal force of the main truss can be calculated according to the plane truss. In design, special attention should be paid on the transverse beam in bridge deck system which plays control action. Longitudinal beam is mainly affected by axial tension and vertical bending. The maximum tensile stress appears at the bottom flange of the center section of each panel and there is little difference between inside and outside. The loading status of concrete slab is mainly from the bending acted by vertical load. Both vertical and horizontal unbalanced loading will not dominate the design.