文档介绍：摘 要
本文着重研究了钢管混凝土结构的力学性能及承载能力,通过对拱肋实体所作的三维有限元分析,验证了钢管混凝土拱桥中钢管对混凝土的环箍效应,证明了由于环箍效应的存在,使内填式钢管混凝土轴压承载力大大提高。在钢管混凝土拱肋断面上,钢管对内填混凝土的环箍效应具有非均匀性,在拱轴方向上环箍效应也呈现非均匀性。验证了材料的横向变形系数、混凝土标号等参数的变化将引起环箍效应的明显改变;混凝土的收缩、徐变和膨胀混凝土的应用导致钢管混凝土的环箍效应发生变化并使截面的应力发生重分布:并总结了其变化豹基本规律。
本文提出在钢管混凝土拱桥的内力计算及设计验算时,可用带有钢带的矩形混凝土截面近似代替多肢桁式钢管混凝土拱截面,并通过ALGOR93程序进行计算分析,在部分方面验证了这种近似替代的可行性,为实际工程设计中计算多肢桁式钢管混凝土拱桥提供了一种可行的计算模式。
关键词:钢管混凝土 环箍效应 有限元分析
横向变形系数 收缩 徐变 膨胀混凝土
Abstract
The paper puts great emphasis on studying the mechanical performance and the carrying capacity of concrete—filled steel tubular(CFST),verifies the cyclo-hoop effect which steel tubular has exert to the concrete in CFST throu曲the tridimensional finite element analysis of the entity of the arch rib,and proves that the cyclo·hoop effect is utilized to increase the pression CFST member carrying cyclo-hoop effect which steel tubular has exert to the concrete
shows the character of heterogeneous in the arch rib section,the same to the axial
paper verifies the change of the material poisson ration and the
concrete grade will make the cyclo—hoop effect obvious alteration,the change of the cyclo-hoop effect and the s扛ess redistribution of the section produced by the shrinking and creeping ofthe concrete and the expensive concrete on the the basal laws ofthese changes arc also summed印in the paper.
In the concrete cross section wi也steel band to replace approximatively the mufti-limb steel tubular truss section is brought up to calculate and cheek calculation in the CFST arch method has been verified partially by the procedure ALGOR93 and can he applied in actual engineering.
Keywords: Concrete-filled steel tubular(CFST) Cyclo-hoop effect Finite element analysis Poisson ration Shrinking Creeping Expensive concrete
第一章论述
自从1897年英国赛文(severn)铁路桥采用钢管混凝土桥墩,钢管混凝土结构在土木工程中的应用和研究已有一百多年的历史。上世纪初,美国在一些单层和多层房屋建筑中采用了称为“Lally Column'’的圆形钢管混凝土柱。上世纪三十年代末期,前苏联建成了跨越列宁格勒涅瓦河的101m钢管混凝土拱梁组