预制混凝土小箱梁结构中横隔板的作用分析

on Effect of Middle Diaphragm in Precast Concrete Small-box Girder Structure

摘要:

随着预制装配技术在国内的蓬勃发展，预制混凝土小箱梁得以大范围应用。预制混凝土小箱梁中横隔板大大增加了现场施工难度、施工时间及工程造价。中横隔板的必要性有待进一步探讨。以30 m+30 m简支变连续预应力混凝土小箱梁工程实例为研究基础，采用虚拟横梁单元法，建立三维Midas Civil 有限元模型，对中横隔板对结构内力影响进行分析，结果显示设置中横隔板对小箱梁边梁活载挠度、弯矩影响不大，使小箱梁边梁腹板变厚处产生更不利剪力及对应扭矩，从而对小箱梁最小截面抗剪扭承载力验算更为不利。

Abstract:

With the rapid development of prefabrication technology in China, the precast concrete small-box girders have been widely used. The middle diaphragm in precast concrete small-box girder greatly increases the on-site construction difficulty, construction time and engineering cost. The necessity of the middle diaphragm is to be further discussed. Based on an engineering example of 30 m+30 m simple-supported variable continuous pre-stressed concrete small-box girder, the virtual beam element method is used to establish a three-dimensional Midas Civil finite element model to analyze the influence of the middle diaphragm on the internal force of the structure. The results show that the installation of the middle diaphragm has little effect on the deflection under live load and bending moment of the side beam of the small-box girder, which makes the thickening place of the side beam web of small-box girder produce the adverse shear force and corresponding torque. Therefore, it is more unfavorable to check the shear and torsion bearing capacity of the minimum section of small-box girder.