钢箱-预应力混凝土组合梁负弯矩区结构性能试验研究  

Experimental study of the structural behavior of the negative bending zone of steel box-prestressed concrete composite beams

作　　者：周安[1] 戴航[2] 刘其伟[2] 

机构地区：[1]合肥工业大学,安徽合肥230009 [2]东南大学,江苏南京210096

出　　处：《土木工程学报》2009年第12期69-75,共7页China Civil Engineering Journal

基　　金：江苏省交通厅资助项目(03y031)

摘　　要：进行5根简支组合梁负弯矩作用下的静力试验,钢梁为开口钢箱梁,混凝土翼板内配置有黏结预应力钢绞线。试验表明:体内预应力能有效控制连续组合梁负弯矩段的抗裂性;钢箱梁底板沿宽度方向应力应变分布明显不均;在完全剪力连接条件下,考虑混凝土翼板贡献的换算截面剪应力分布的计算值与实测值基本吻合。推导给出考虑预应力度、混凝土收缩及钢纤维影响的组合梁负弯矩区混凝土开裂弯矩计算公式。针对预应力混凝土组合梁负弯矩段在正常使用阶段开裂受到控制,提出考虑混凝土贡献的组合梁挠度计算的变刚度法,使荷载-挠度的计算曲线与试验曲线全程逼近。Five simply supported composite beams,composed of open section steel box girder and prestressed concrete flange with bonded steel strands,were tested under negative moments with static load conditions. The experimental result indicates that the prestressing in a continuous beam can effectively inhibit the initiation and development of cracks in the negative moment zone. The stress and strain distributions in the flange of the steel box girder were not uniform. Under the condition of pure shear connection,the calculated shear stress distribution,with effect of the concrete flange taken into account,agreed well with the test results. A method is presented for calculation of concrete cracking moment in the negative moment zone,in which the effects of prestressing,the shrinkage of concrete and steel fiber were considered. Considering the contribution of concrete and the fact that the concrete cracks are highly restricted in the negative moment zone in normal working stage,a variable stiffness method for calculation of the deflection of composite beam members was proposed. The calculated load-deflection curves were in good agreement with the test results.

关 键 词：钢-混凝土组合梁 预应力 结构性能 试验研究 

分 类 号：TU398.9[建筑科学—结构工程]