为研究温度效应对连续刚构桥空心薄壁墩受力行为的影响,以(98+5 × 185+98)m变截面预应力混凝土连续刚构桥——三水河特大桥主桥为背景,通过现场温度场测试,研究桥墩垂直温度场和水平温度场的分布规律,并以实测温度场为依据,选取对桥墩刚度影响较大的桥墩高度、顺桥向宽度和壁厚作为关键参数,分析整体均匀温度T和梯度温度△T对空心薄壁墩受力的影响.结果表明:实测桥墩垂直温度场随着墩高的变化分布差异较小,水平温度场受日光照射影响较大,桥墩夏季的梯度温度值约为冬季的2倍.墩高对桥墩温度应力的影响基本呈反比关系,顺桥向宽度对墩底温度应力的影响呈线性增长趋势,壁厚与温度应力呈反比关系.对于长联刚构桥,为减小桥墩的温度效应,建议边主墩高度不宜小于60 m,桥墩顺桥向宽度宜尽量减小,桥墩壁厚宜取80～100 cm.
Research on Temperature Field and Temperature Effect in Piers of Sanshui River Bridge
This study investigates the temperature effects on the load bearing performance of hollow thin-walled piers.The main bridge of Sanshui River Bridge,a prestressed concrete continuous rigid-frame bridge with five spans of 185 m and two spans of 98 m,was used as a case.The temperature fields were tested,and the distributions of vertical and horizontal temperature fields were analyzed.With the measured data of temperature fields,the key parameters that are closely related to the stiffness of piers,including pier height and width(along bridge length),and wall thickness,were drawn upon to analyze the effects of overall uniform temperature T and gradient temperature △T on the load bearing performance of the hollow thin-walled piers.It is shown that the measured vertical temperature fields in piers exhibit minimal variation along pier height,while the horizontal temperature fields are sensitive to solar radiation,with gradient temperatures in summer two times of those in winter.The temperature stresses in pier bottom are inversely proportional to the pier height and wall thickness,but in linear relation to the pier width.For the rigid-frame bridge with long expansion units,it is suggested to make the heights of the edge main piers no less than 60 m,and reduce the pier width(along bridge length)as much as possible,and set the pier wall thickness between 80 and 100 cm.
万方数据
维普
