V型墩连续刚构桥0号块空间应力分析及优化设计  

Analysis on Spatial Stress and Optimal Design of Block No.0 of Continuous Rigid Frame Bridge with V-shaped Piers

作　　者：张飞[1] 黄福云[2] 王燕 ZHANG Fei;HUANG Fu-yun;WANG Yan(School of Engineering,Fujian Jiangxia University,Fuzhou Fujian 350108,China;School of Civil Engineering,Fuzhou University,Fuzhou Fujian 350116,China)

机构地区：[1]福建江夏学院工程学院,福建福州350108 [2]福州大学土木工程学院,福建福州350116

出　　处：《公路交通科技》2019年第11期59-67,共9页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51578161);福建省教育厅中青年教师科研项目(JAT170614;JT180571)

摘　　要：V型墩连续刚构桥0号块由于其特殊的结构构造和复杂的边界条件,该区域的空间应力状态复杂,设计中常采用杆系模型对其进行力学分析,误差较大。为此,以某V型墩连续刚构桥0号块为研究对象,对其空间应力和结构优化进行分析。采用光弹性应力法试验和数值分析相结合的方法,建立0号块的实体模型。从三向正应力和边界切向正应力的角度揭示其在施工最大悬臂阶段和运营阶段的应力分布特征,绘制关键位置的切片边界应力分布曲线。结果表明:试验值和有限元值相吻合,主梁结构以压应力为主,满足全预应力混凝土结构的设计要求;横隔板人孔周边有横桥向的拉应力集中,箱梁顶板和底板与横隔板折线过渡处有顺桥向的压应力集中;V撑与竖墩的固结区是结构的应力危险区域,建议在此区域加强防裂钢筋配置或采用钢纤维混凝土。最后,为了优化V型墩刚构桥的受力特点,提出了增加竖墩高度的优化措施,使其表现出柔性墩特性。随着竖墩高度的增加,V撑各截面的应力梯度递减,截面上应力分布趋于均匀。当其高度大于墩顶梁高的5倍时,V墩各截面的应力梯度小于0.6,受力合理,安全储备大,适应运营阶段由于后期混凝土收缩和徐变、升降温等引起的主梁纵向水平位移的效果更好。Because of the special structure and the complex boundary condition of the block No.0 of continuous rigid frame bridge with V-shaped piers,the spatial stress state of this area is rather complex.However,the beam-column elements model is usually adopted for mechanical analysis in design which induced large error.Therefore,taking the block No.0 of a continuous rigid frame bridge with V-shaped piers as the research object,its spatial stress and structural optimization are analyzed.A solid model of block No.0 is established by using the methods of photoelastic stress experiment and numerical analysis.The stress distribution characteristics of the block No.0 in the longest cantilevered stage and operational stage are revealed in view of tri-directional normal stress and boundary tangential normal stress,and the curve of the stress distribution of slice boundary at key position are drawn.The result shows that(1)the experimental values are consistent with the finite element analysis values,the compressive stress is dominant in main girder structure,which meets the design requirements of fully prestressed concrete structure;(2)the tensile stress concentration appears around the hole of the diaphragm in bridge transverse direction,while the compressive stress concentration appears at the joints between the top/bottom plates of the box girder and the diaphragm in bridge longitudinal direction;(3)the consolidation zone between the V-shaped bracing and the vertical pier is the most dangerous area of the structure,where the structural measurements of increasing the reinforcement or using steel fiber reinforced concrete are proposed.At last,to optimize the mechanical characteristics of the bridge,the optimization measure for increasing the height of the vertical pier is put forward to present the property of e flexible pier.As the height of the pier increases,the stress gradient of each section of the V-shaped bracing decreases,and the distribution of cross-section stress tends to be uniform.When the height of the pier is grea

关 键 词：桥梁工程 空间应力 优化设计 光弹性试验 数值分析 V型墩 

分 类 号：U442[建筑科学—桥梁与隧道工程]