双跨波纹钢拱桥力学性能的试验研究

Field Test of a Medium Size Double Span Box-type Corrugated Steel Bridge

本文研究了一座双跨13 m跨径波纹钢拱桥在静载和动载作用下的力学性能,静载测试了五种工况,动载测试了20 km/h、40 km/h、60 km/h和80 km/h四种车速。通过对截面应变、拱顶位移、动应变和内力分析,得出以下结论:双跨波纹钢拱桥的两跨会相互影响,当车辆作用于一跨时,该跨产生竖向和水平变形,水平变形会使土体挤压另一跨;测试的双跨波纹钢拱桥的轴力较大,不能被忽略,并且轴力大部分表现为拉力;路面结构层对波纹钢拱桥的整体性能有影响,发挥着类似减压板的功效,使整体受力更均匀,弯矩更小;拱顶应变在某一特定车速下达到最大值,车辆作用频率越接近结构自振频率,产生的动态响应越大;应变动力增大系数小于1。

The mechanical properties of a 13 m double-span corrugated steel arch bridge under static and dynamic loads are tested under five static load and four dynamic load conditions,including 20,40,60,and 80 km/h.The following conclusions can be drawn through the analysis of section strains,vault displacements,dynamic strains,and internal forces:(1)The two adjacent spans of the double-span corrugated steel bridge interact with each other.When a vehicle acts on one span,the span will generate vertical and horizontal deformation,and the horizontal deformation will cause the soil to squeeze the other span;(2)The axial force of the tested double-span corrugated steel arch bridge is large and cannot be ignored,and most of the axial force is tensile force.The pavement structure layer affects the overall performance of the corrugated steel arch bridge,which is similar to the decompression plate,it makes the overall stress more uniform and reduces the bending moment;(3)The vault strains do not always increase with the increase of vehicle speed,the closer the frequency is to the natural frequency of the structure,the greater the dynamic response is;(4)The dynamic increasing strain coefficientis less than 1.