双线铁路箱梁施工过程中端块的受力分析

Mechanical Analysis of End Block of a Double-track Railway Box Girder During Construction

研究目的:为了满足施工中预应力钢筋张拉及锚固的需要,箱梁端部在构造上较为复杂。而在预应力筋初张拉、终张拉、落梁以及二期恒载作用下,对于各个阶段端块的受力及其变化状况尚需进一步分析与探讨。研究方法:结合某客运专线双线桥预应力混凝土简支整体箱梁的施工,对于其施工过程中端块的受力进行了分析计算和讨论。按实体块单元的有限元计算理论,建立全梁整体分析的三维空间有限元模型,从计算结果中提取出端块部分的受力情况进行比较和分析。研究结果:通过在不同阶段施工荷载作用下端块的受力计算,给出端块内外侧截面的受力情况,进而对双线铁路整体箱梁的端部在设计及施工中应注意的问题进行了探讨。

Research purposes：In order to satisfy with the pretension and anchorage of prestress, the structure of end section of box beam is always complex. The mechanical properties of end section of box beam need further study at the stages of primary and final pretension, beam erection and secondary dead load action. Research methods： According to construction of a double lines railway bridge with simple supported PC box beam, the mechanical properties of end section are analyzed and researched during construction. Using solid element method, three dimensions model of finite element of whole box beam is set up. The mechanical properties of end section is compared and analyzed. ReSearch resuits： According to different load conditions at construction stage, the mechanical properties of internal and external sides of end section are presented. The noticed problems of design and construction of end section of box beam for double lines railway bridges are investigated.