桁架箱梁斜拉桥结构力学性能研究

发布时间：2018-05-01 06:00

本文选题：桁架箱梁斜拉桥 + 静力性能　；参考：《天津大学》2014年博士论文

【摘要】：由于铁路桥梁所受的静荷载和动荷载都很大,因此常常采用组合结构桥梁的形式。随着国家铁路网的逐步完善,以往提出的各种组合结构桥梁(如钢-混凝土组合、梁-拱组合等)被越来越多地应用于铁路桥梁中,但是仍然不能满足铁路桥梁建设的需求。因此,提出新的组合结构桥梁形式,并对其力学性能进行分析,具有十分重要的理论意义和工程应用价值。本文主要内容如下：(1)在原有桁架箱梁斜拉桥的基础上,结合铁路荷载特点,对桁架箱梁和斜拉索进行改进,形成桁架箱-刚性拉杆斜拉桥结构,该结构斜拉索采用预应力混凝土刚性拉杆,桁架箱梁采用钢管混凝土腹杆和预应力混凝土翼缘板箱梁。(2)分析了桁架箱梁-刚性拉杆斜拉桥与桁架箱梁-柔性拉索斜拉桥在列车荷载作用下的受力性能和变形。结果表明,桁架箱梁-刚性拉杆斜拉桥箱梁的位移和应力均较小；给出了箱梁构造参数和刚性拉杆截面尺寸对箱梁受力性能的影响规律。(3)分析了拉索形式和腹杆中是否填充混凝土对桁架箱梁斜拉桥动力特性的影响。结果表明,桁架箱梁-刚性拉杆斜拉桥抗振动性能优于桁架箱梁-柔性拉索斜拉桥,腹杆中填充混凝土能够改善桁架箱梁斜拉桥的动力特性；给出了箱梁构造参数和刚性拉杆截面尺寸对结构动力特性的影响规律。(4)分析了桁架箱梁-刚性拉杆斜拉桥与桁架箱梁-柔性拉索斜拉桥的抗震性能,以及腹杆中填充混凝土对结构抗震性能的影响。结果表明,桁架箱梁-刚性拉杆斜拉桥位移响应较小；腹杆中填充混凝土可以改善结构的抗震性能。(5)针对桁架箱梁-刚性拉杆斜拉桥特点,基于能量原理推导了考虑刚性拉杆扭转变形的桥塔侧向弹性稳定系数的理论公式。利用有限元法和修正的弹性支承法对一算例桥塔侧向稳定系数进行了计算,本文推导公式的计算结果与其吻合较好,验证了本文理论公式的正确性。(6)利用本文推导的桥塔侧向弹性稳定系数理论公式,对辐射式、竖琴式和扇形三种索面类型斜拉桥拉杆倾角对桥塔侧向弹性稳定性的影响进行了分析,得到了拉杆倾角对不同索面斜拉桥桥塔侧向稳定性的影响规律。结果表明,竖琴式索面刚性拉杆斜拉桥的桥塔稳定系数较高,受拉索倾角的影响较小。因此,建议刚性拉杆斜拉桥索面类型采用竖琴式。
[Abstract]:Because railway bridges are subjected to large static and dynamic loads, composite structure bridges are often adopted. With the gradual improvement of the national railway network, various kinds of composite structure bridges (such as steel-concrete combination, beam-arch combination, etc.) have been used more and more in railway bridges, but they still can not meet the needs of railway bridge construction. Therefore, it is of great theoretical significance and engineering application value to put forward a new form of composite structure bridge and analyze its mechanical properties. The main contents of this paper are as follows: (1) on the basis of the original truss box girder cable-stayed bridge and combined with the characteristics of railway load, the truss box girder and cable-stayed cable are improved to form the truss box-rigid stayed bar cable-stayed bridge structure. The cable of this structure adopts prestressed concrete rigid tension rod, The behavior and deformation of truss box girders with concrete filled steel tube web and prestressed concrete flange slab box girder are analyzed under the train load. The truss box girder rigid stayed cable cable-stayed bridge and truss box girder flexible stayed cable cable-stayed bridge under train load are analyzed. The results show that the displacement and stress of box girder of truss box gird-rigid stayed cable-stayed bridge are small. The influence of box girder structural parameters and section size of rigid strut on the mechanical behavior of box girder is given. The influence of cable form and whether the web bar is filled with concrete on the dynamic characteristics of truss box girder cable-stayed bridge is analyzed. The results show that the vibration resistance of truss box girder rigid stayed cable-stayed bridge is better than that of truss box girder flexible cable stayed bridge. The dynamic characteristics of truss box girder cable-stayed bridge can be improved by filling concrete in web bar. The influence of box girder structural parameters and section size of rigid stayed rod on the dynamic characteristics of the structure is given. (4) the seismic behavior of truss box girder rigid stayed cable-stayed bridge and truss box girder flexible cable stayed bridge is analyzed. And the effect of filled concrete on seismic performance of the structure. The results show that the displacement response of truss box girder-rigid stayed cable-stayed bridge is small, and the concrete filled with web bar can improve the seismic performance of the structure. Based on the energy principle, the theoretical formula of lateral elastic stability coefficient of bridge tower considering torsional deformation of rigid rod is derived. The lateral stability coefficient of a bridge tower is calculated by using the finite element method and the modified elastic support method. The correctness of the theoretical formula of this paper is verified. (6) using the theoretical formula of lateral elastic stability coefficient of bridge tower derived in this paper, In this paper, the influence of bar inclination angle on the lateral elastic stability of the tower of cable-stayed bridge with three types of cable plane is analyzed, and the influence law of the inclination angle of tension bar on the lateral stability of tower of cable-stayed bridge with different cable plane is obtained. The results show that the stability coefficient of the bridge tower is higher and the influence of cable inclination is small. Therefore, it is suggested that the type of cable surface of rigid stayed-bar cable-stayed bridge should be harp type.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U441;U448.27

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