预应力矮肋T梁桥跨中横隔梁力学性能及计算方法分析

由于预应力矮肋T梁桥结构高度小,主梁抗扭刚度小,桥梁在受力时,力在桥梁上的横向分布会与普通T梁不同,横隔梁的力学性能也会发生变化。为了解预应力矮肋T梁桥跨中横隔梁的力学性能以及掌握预应力矮肋T梁桥跨中横隔梁的合理计算方法,本文通过全桥有限元分析方法、偏心压力法理论对预应力混凝土矮肋T梁桥跨中横隔梁进行受力性能分析,然后与现场试验结果进行对比分析。结果表明:横隔梁截面应力沿梁高成线性分布;有限元分析方法的计算结果与试验结果的最大误差为9.4%,最小误差为1.5%;运用偏心压力法的计算结果与试验结果的最大误差为27.7%,最小误差为10.5%;采用偏心压力法计算的中性轴位置与实际中性轴位置有偏差。可见横隔梁受力均匀,工作状态良好;全桥有限元分析方法可很好的模拟预应力矮肋T梁桥横隔梁的受力性能,理论计算的横隔梁的应力与试验结果吻合,误差小于9.4%,计算精度高,可用于实际工程设计当中;采用偏心压力法理论对预应力矮肋T梁桥的横隔梁进行内力计算是不太适用的,计算精度不高,不能真实的反应梁的实际受力情况;偏心压力法理论计算不够精确的原因是受压翼缘板的有效翼缘宽度计算不够合理。

The mechanical response of multi-tower continuous-span suspension bridge deck pavement based on whole bridge analysis

The effect of multiple span suspension structure on the mechanical response of bridge deck pavement was studied, and finite element analysis (FEM) of stress and strain of pavement according to the bridge floor system features of super-long and high flexibility was made. Meanwhile, the FEM results were compared with those of the single span suspension structure. Three-stage analytic hierarchy process (AHP) is developed to analyze the mechanical response including whole bridge analysis, partial beams section analysis and orthotropic plate analysis. The most unfavorable load position was determined by the numerical solutions acquired from each stage to study the main mechanical index of multiple span suspension structure. The FEM results showed that the mechanical response numerical solutions by using the three-stage AHP are greater than those by simplified boundary condition, and the force condition of multiple span suspension structure is worse than that of the single span suspension structure.