铁路大跨双薄壁矮墩连续刚构桥设计研究

Study on Design of Long-span Continuous Rigid Frame Railway Bridge with Low Double Thin-wall Pier

为确定矮墩大跨连续刚构桥较为合理的设计参数,以兴泉铁路永安沙溪特大桥主桥(90+168+90)m连续刚构为研究对象,在分析矮墩大跨连续刚构桥受力特点的基础上,运用有限元软件建模计算,研究控制刚构桥设计的刚壁墩壁厚、刚壁墩间距、承台结构型式、桩土效应及地基系数的比例系数等参数对桥墩内力及刚度的影响。分析表明:刚壁墩壁厚对墩身内力影响较为敏感,考虑桩土效应能有效改善桥墩结构的受力,据此确定了本桥合理的墩身结构尺寸及计算分析模拟方法,可为同类工程提供技术参考。

To determine the optimal design parameters of low-pier and long-span continuous rigid frame bridge,the continuous rigid frame bridge project of Shaxi extra-long bridge with a main bridge of（ 90 ＋ 168 ＋ 90） m on XingguoQuanzhou railway is taken as the engineering background. Based on the analysis of the stress characteristics of the low-pier and long-span continuous rigid frame bridge,the influence of such parameters as thickness of rigid wall pier,distance between rigid wall piers,bearing platform structure pattern,pile-soil effect and proportion coefficient of foundation coefficient which dominate the bridge design on the internal force and stiffness of pier is studied by using the finite element analysis software. The results show that the thickness of rigid wall pier has the greater influence on the internal force of pier body and to consider pile-soil effect can effectively improve the stress of pier structure. Based on the results,the reasonable structural dimension of pier body and calculation and analysis simulation method of this bridge are determined,which can provide technical reference for similar projects.