Optimum design of large span concrete filled steel tubular arch bridge based on static,stability and modal analysis

A three-dimensional finite element model was established for a large span concrete filled steel tubular (CFST) arch bridge which is currently under construction. The arch rib, the spandrel columns, the prestressed concrete box-beam, the cast-in-situ concrete plate of bridge deck, the steel box-beam and the crossbeams connecting the two pieces of arch ribs, were modeled by three-dimensional Timoshenko beam elements (3DTBE). The suspenders were modeled by three-dimensional cable elements (3DCE). Both geometric nonlinearity and prestress effect could be included in each kind of element. At the same time a second finite element model with the same geometric and material properties excepted for the sectional dimension of arch rib was set up. Static dynamic analyses were performed to determine the corresponding characteristics of the structure. The results showed that the arch rib's axial rigidity could be determined by static analysis. The stability and vibration of this system could be separated into in-plane modes, out-of-plane modes and coupled modes. The in-plane stability and dynamic characteristics are determined by the arch rib's vertical stiffness and that of out-of-plane is determined by the crossbeams' stiffness and arch rib's lateral stiffness mainly. The in-plane stiffness is much greater than that of out-of-plane for this kind of bridge . The effect of geometric nonlinearity and prestress effect on bridge behavior is insignificant.     

Design and research of gymnasium structure in Zhejiang University

INTRODUCTION The gymnasium project located in the newcampus of Zhejiang University is a symbol building(Fig.1). The requirements on the functions and theesthetics make it distinguished from a traditionalgymnasium. It is a two-story building with the firstfloor used for field competition and the second floorfor students’ basketball training. The heavy live loadsacting on the second floor and the requirement of 35m unobstructed space challenge the creativity of thestructural enginee…     

预应力钢绞线张拉程序及影响因素分析

在桥梁施工中,连续刚构施工作为一种山区首选桥型在实际应用中非常广泛。其中,预应力施工工艺又是连续刚构施工过程中很重要的一项技术应用。本文介绍了预应力钢绞线张拉程序及相关的计算方法,结合具体工程实例,进行相关技术分析。为同类工程施工提供借鉴。