摘要
建立了轻型桥台自身平面内弯曲分析的双参数地基Timoshenko梁模型,简要讨论了其退化形式和适应性能.基于微分方程的初参数解,建立了双参数地基Timoshenko梁的传递矩阵法;基于Timoshenko梁单元的位移插值函数,建立了双参数地基Timoshenko梁有限元列式.通过算例分析,发现轻型桥台自身平面内弯曲存在最大弯矩位于对称中心和偏离对称中心两种情况;利用ANSYS空间有限元模型对此现象进行了验证.讨论了桥台变形和内力随桥台襟边宽度和地基不均匀的变化规律.鉴于轻型桥台自身平面内弯曲存在最大弯矩偏离对称中心且比对称中心截面弯矩大、对称中心截面弯矩是局部最小值的可能现象,建议教材《桥梁工程》和专业文献摈弃以对称中心截面弯矩作为最大值的简化设计计算方法,对计算理论进行补充和完善.地基不均匀显著影响桥台的变形和内力,简单地取最软或最硬地基参数进行桥台弯曲分析不能得到最大内力值,不是安全的设计计算方法.
The Timoshenko beam model on a two-parameter foundation is presented for the flexural analysis of light type abutment in its self-plane.Its degenerating formulations and adaptability are discussed briefly.Based on the initial parameter solutions to the differential equation,the transfer matrix method is established for the Timoshenko beam on the two-parameter foundation.Based on the interpolation functions of the Timoshenko beam element,the finite element formulation of the Timoshenko beam on the two-parameter foundation is achieved.Numerical example results demonstrate that there are two phenomena found with the maximal moment position located on and deviating from the symmetrical center.Spatial finite element analyses of ANSYS are carried out and verify the phenomena.The variation laws of deformations and internal forces of the abutment in its self-plane are investigated along the tread width and non-uniformity of foundation.Given that the maximal moment position in the self-plane of light abutment deviates from the symmetrical center,the quantity is greater than that of the symmetrical center,and the moment at the symmetrical center is a local minimum,the current simplified method and design process with the center moment as the maximal result are suggested to be abandoned in many bridge engineering literature.The relevant theories need to be improved and refined.The unevenness of the foundation affects the deformations and inner forces in light abutment.The simple operation adopting the relevant parameters of the softest or the hardest foundations fails to achieve the maximum results,which is not safe for design practices.
作者
夏桂云
刘洪
XIA Guiyun;LIU Hong(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China;Key Laboratory of Bridge Engineering Safety Control,Ministry of Education(Changsha University of Science&Technology),Changsha 410114,China)
出处
《湖南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2024年第11期167-176,共10页
Journal of Hunan University:Natural Sciences
基金
国家自然科学基金资助项目(51278072)
湖南省教育厅重点项目(22A0223)。
