空间系杆拱桥吊杆张拉控制分析

Control Analysis of the Tension in Suspenders of a Spatial Tied-arch Bridge

针对空间系杆拱桥吊杆张拉控制问题提出倒装法和影响矩阵法两种计算方法 .倒装法采用逆序法计算结构的阶段内力 ,利用温度应力模拟吊杆张拉力 ,并用间隙单元精确模拟了结构脱离支撑的过程 .影响矩阵法以每根吊杆应该施加的初始张拉力为基本未知值 ,根据吊杆的张拉顺序利用有限元软件Ansys求出单位力作用下的吊杆内力矩阵 ,建立典型方程 ,通过简单的回代方法求出每根吊杆张拉控制力 ,从而使得最终吊杆的预张拉力达到规定的设计值 .这两种方法计算简便易行 ,两者计算结果一致 ,精确可靠 。

Tow methods,flip-chip method and influence matri x method,were proposed to calculate the suspender tension in a spatial tied-arch bridge.In the flip-chip method,the athwart order is adopted to calculate the subsection internal force of the structure,the temperature stress is utilized to simulate the stretching force in the suspen-der,and the gap element is adopted to accurately simulate the deviation process of the structure from the support.In the influence matrix method,according to the sequence of suspender tensions,firstly,the initial pre-stress in each suspender is considered as an unknown variable;next,the internal tension matrix is obtained by using Ansys for the finite element analysis;then,the typical equations were established;finally,the tension of each suspender is calculated by the simple iteration method,thus ensuring the pre-stress of the suspender achieves the design value.Both of the two simple practical methods are of accurate and consistent calculation results,which provides good reference for the construction of similar bridges.