下承式钢管混凝土系杆拱桥拱脚局部应力分析

LOCAL STRESS ANALYSIS OF ARCH BRIDGE WITH LOWER SUPPORTED STEEL PIPE CONCRETE TIE

拱脚是钢管混凝土拱肋向混凝土的过渡段,局部构造复杂,是拱梁组合桥的关键部位,其受力性能对全桥承载能力和跨越能力至关重要。运用ANSYS软件建立拱脚三维空间有限元模型,计算分析了拱脚在拱肋张拉吊杆前后两种工况下应力的空间分布。根据分析结果可以得到,拱脚受力以纵向压力为主,应力分布较为均匀;局部出现小范围拉应力,且拉应力值不大。因此,在整个拱桥结构中,拱脚受力合理,满足实际工程需要。

The skewback,whose local structure is complex,is the transition from the concrete filled steel tubular arch rib to the skewback concrete. In addition,the skewback is the key part of the beam-arch combination bridge and its mechanical behavior is important for the carrying capacity and span ability of the full-bridge. The ANSYS is used to establish the three-dimensional space FEM of skewback. The Spatial distribution stress of skewback is calculated and analyzed under the conditions that before and after suspender tension. According to the analysis results,the main skewback force is longitudinal compressive stress and the stress distribution is uniform. Except the compressive stress,the tensile stress appears in the small range and the value is not large. Therefore,the skewback force is reasonable in the full- arch bridge structure and meets the practical engineering requirement.