槽型断面梁斜拉桥塔梁墩固结区受力特性研究

为增大桥梁纵向刚度、便于转体施工,沪昆客运专线上某(32+80+112)m槽型截面独塔斜拉桥将槽型梁两边箱插入塔柱中形成塔梁墩固结体系,其构造和受力情况极为复杂.为研究该桥塔梁墩固结区域的应力分布情况,采用大型通用有限元软件ANSYS建立塔梁墩固结区局部模型并验证模型正确性.在此基础上,分析固结区域结构传力路径和应力分布规律,探讨局部设计细节对固结区应力的影响.研究表明:塔梁墩固结区内整体应力水平低于固结区范围以外截面,但在槽型梁过渡至固结区内部的交接角以及固结区内部过人洞折角等处存在应力集中现象.通过改进结构设计细节可有效缓解各处的应力集中现象.

Stress Analysis of Pier-tower-girder Fixed Region of Cable-stayed Bridge with Trough Girder

In order to increase the structural longitudinal stiffness and facilitate the swing method, the side girders of trough section of the cable-stayed bridge on the Kunming-Shanghai passenger line were inserted into the pylon so as to form the pier-tower-girder fixed region. For the (32+80+112) m single tower cable-stayed bridge, the structure and force of the fixed region are very complicated. The large general-purpose finite element software ANSYS was used to establish the pier-tower-girder fixed region model to study the stress distribution of the fixed region. The correctness of this model was verified. Based on this region model, the force transmission and stress distribution of the fixed region were investigated, and the effect of the local structural details on the fixed region stress was studied. The analysis results show that the global stress level of the fixed region is lower than the girder and tower, but there are stress concentration phenomena in the fixed region, such as the intersection point between the floor of the trough girder and upper tower, and the corner of the human tunnel in the fixed region. The degree of the stress concentration was relieved significantly by improving the structural details.