斜支承箱梁的日照温度次内力研究  

Study on the secondary internal forces in skew box girders induced by sunshine temperature gradient

作　　者：张元海[1] 李乔[2] 

机构地区：[1]兰州交通大学,甘肃兰州730070 [2]西南交通大学,四川成都610031

出　　处：《土木工程学报》2008年第5期46-51,共6页China Civil Engineering Journal

基　　金：甘肃省自然科学基金(3ZS042-B25-032);兰州交通大学“青蓝”人才工程基金(QL2004-A16)

摘　　要：为了研究斜支承箱梁在非线性日照温度梯度作用下的结构性能,推导了日照温度初内力的一般公式,并针对指数曲线和折线两种温度梯度模式给出初弯矩的具体表达式,在此基础上,进一步推导了单跨斜支承箱梁和多跨斜支承连续箱梁的日照温度次内力公式。以基本公式为依据,编制相应电算程序,结合工程实例,详细分析了斜度和弯扭刚度比对单跨斜支承箱梁和多跨斜支承连续箱梁日照温度次内力的影响,绘制的大量曲线清晰显示了其影响规律。研究结果表明,无论是多跨斜支承连续箱梁还是单跨斜支承箱梁,在非线性日照温度梯度作用下都会产生很大的次弯矩和次扭矩,斜度和弯扭刚度比对次内力有显著影响。In order to investigate the mechanical behavior of skew box girders under nonlinear sunshine temperature gradient, general formulas for the primary internal forces by the sunshine temperature gradient are derived. The expression for the primary bending moment is presented according to exponential curve and broken line gradient modes. The formulas of the secondary internal forces are further derived for both single span and multiple-span continuous skew box girders. The corresponding computer code is developed. The influence of skew angle and ratio of bending and torsion stiffness on the secondary internal forces of single span and multiple-span continuous skew box girders is analyzed in detail through an example. A large number of curves clearly show the influence patterns. Large secondary bending and torque moments occur in both the multiple-span continuous and the single span skew box girders under nonlinear sunshine temperature gradient. Skew angle and the ratio of bending and torsion stiffness significantly affect the secondary internal forces of skew box girders.

关 键 词：斜交箱梁 温度效应 次内力 初内力 非线性温度梯度 斜支承 

分 类 号：U448.24[建筑科学—桥梁与隧道工程] U448.213[交通运输工程—道路与铁道工程]