预应力荷载效应的精确解析方法  

Accurate Analytical Method of Load Effect of Prestress

作　　者：孟阳君[1] 周先雁[1] 

机构地区：[1]中南林业科技大学,湖南长沙410004

出　　处：《公路交通科技》2014年第6期94-100,共7页Journal of Highway and Transportation Research and Development

基　　金：湖南省自然科学基金项目(06JJ21001)

摘　　要：针对预应力荷载效应的等效荷载法不完全适用于桥梁工程实际情况,从等效荷载法假设的不足——仅适用于索曲线近似视为二次抛物线,且曲率平缓的情况出发,根据材料力学的基本原理,不限曲率变化,从理论上详细推导了抛物线、圆曲线、直线及上述几种线形组合布置的索曲线的荷载效应计算公式。同时得到了斜率变化在满足工程精度要求,即5°范围内的简化计算公式。结合深梁曲线预应力荷载效应和箱梁0#块曲线预应力荷载效应的工程算例,采用解析法公式进行分析,并用ANSYS软件进行模拟计算。计算结果表明,两者最大误差小于5%,验证了针对上述几种线形的荷载效应计算公式是正确有效的。In view of the equivalent load method for prestressed load effect is not fully applicable to bridge engineering, from the perspective of the defect of the hypothesis of the equivalent load method which only applied to cable curve approximatively as quadratic parabola and curvature gentle. According to the basic principle of material mechanics and without limitation of curvature variation, the load effect calculation formulas of the cable curves about parabolic curve, circular curve, straight line and the several combinations of these curves are derived. Meanwhile, the simplified calculation formulas about the slope changes in the range of 5° which can meet the project accuracy requirement are also put forward. At the end, combining with the engineering examples of a deep beam with curved prestress load effect and 0# block in a prestress load effect box girder with curved prestress load, analytical method and ANSYS software are used for analysis and simulate calculation. The results show that the maximum errors of the 2 engineering examples are less than 5%, which verified that the abovementioned formulas are correct and effective.

关 键 词：桥梁工程 荷载效应 解析法 预应力 圆曲线 抛物线 直线 

分 类 号：U441.2[建筑科学—桥梁与隧道工程]