基于材料强度的无背索斜拉桥极限跨径研究  

Research on Ultimate Span of Cable-Stayed Bridge Without Back Cable Based on Material Strength

作　　者：葛欢 林丽霞[1] GE Huan;LIN Lixia(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070

出　　处：《结构工程师》2023年第4期19-25,共7页Structural Engineers

摘　　要：基于平均索法和索膜法二者的等效原则分别推导了斜拉索对主梁产生的轴力解析式,考虑斜塔倾角和斜拉索自重的影响,得到了无背索斜拉桥极限跨径表达式。对无背索斜拉桥在竖向荷载作用下的极限跨径进行了研究,得到了自重作用下的极限跨径上限,并对主梁截面面积、索距比、高跨比以及恒活载比等影响极限跨径的因素进行了分析。结果表明:极限跨径的大小与斜塔倾角、塔高、索距比以及荷载情况有关;可以通过减小恒载、增加索距比以及减小高跨比等措施来增大极限跨径。平均索法与索膜法计算轴力的结果均与有限元结果相吻合,索膜法作为一种偏于安全的轴力计算方法,可用于无背索斜拉桥轴力的近似计算。Based on the equivalent principle of average-cable method and cable-membrane method,the analytical expressions of axial force caused by cable on main girder are derived,and the ultimate span expression of cable-stayed bridge without back cable is obtained considering the influence of tower inclination angle and cable self-weight.The ultimate span of cable-stayed bridge without back cable under vertical load is studied and the upper limit of ultimate span under self-weight is obtained.Factors affecting the ultimate span,such as sectional area of main girder,cable spacing ratio,height-span ratio and live load ratio,are analyzed.The results show that the ultimate span is related to the inclination angle,tower height,cable spacing ratio and load.The ultimate span can be increased by reducing self-weight,increasing cable spacing ratio and decreasing height-span ratio.The results of the average cable method and the cable membrane method are in good agreement with the finite element results.As a conservative method of axial force calculation,cable membrane method can be used for the approximate calculation of axial force of cable-stayed bridges without back cables.

关 键 词：无背索斜拉桥 理论分析 极限跨径 平均索法 索膜法 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]