预应力装配式鱼腹梁内支撑的刚度分析  

Analysis on Stiffness of Inner Support for Pre-stressed Assembled Fish-bellied Beam

作　　者：刘发前[1] 卢永成[1] 

机构地区：[1]上海市政工程设计研究总院(集团)有限公司,上海市200092

出　　处：《城市道桥与防洪》2016年第2期154-156,168,共4页Urban Roads Bridges & Flood Control

基　　金：上海市青年科技启明星课题(2014B类)(14QB1404100)

摘　　要：预应力装配式鱼腹梁内支撑系统由于其＂敞开式＂的布置方式,施工作业面大,速度快。同时,由于该类支撑可循环利用,建筑垃圾少,具有很大发展潜力。然而,很多方面仍需进一步研究。结合南京绕城公路地道工程,对预应力装配式鱼腹梁内支撑的刚度进行专项分析,并给出合理建议值。以往经验表明,支撑每延米刚度可达40~50 MN/m,且没有施加预加力。研究表明,这仅在基坑宽度不大时尚可满足。当基坑跨度较大时,支撑刚度线性降低而承载力不变,为增加支撑刚度必须增加型钢数量,经济性很差。最后,提出设计中应采用考虑预应力影响的＂表观刚度＂,可更好地平衡考虑支撑刚度和强度。工程实践表明,并将之应用于南京绕城公路地道设计中,获得良好效果。The construction operation side of the inner support system of pre-stressed assembled fish-bellied beam is large and its speed is fast because of its open layout mode. At the same time, the construction waste of this support is a few by reason of its cyclic utilization. This kind of support has the great development potentiality. However, there are many aspects to be further studied. Combined with the Nanjing Ring Road Tunnel Project, the article specially analyzes the stiffness of the inner support for the pre-stressed assembled fish-bellied beam, and gives the reasonable proposed value. The relative experience shows that the stiffness to support every linear meter can be 40~50 MN/m without the applied pre-stressing force. The study shows that it can be satisfied when the foundation pit is not large. The stiffness linearity of support reduces, but the bearing capacity is not changed when the span of foundation pit is larger. In order to increase the stiffness of support, it must be to increase the quantity of structural steel, but the economy is poor. The article puts forward to use and consider the pre-stressing influence of 'apparent stiffness', which can better balance the stiffness and intensity of support. The engineering practice shows that it has good effect and can be used in the design of the ring road tunnel of Nanjing.

关 键 词：基坑 鱼腹梁 围护结构 刚度 

分 类 号：TU47[建筑科学—结构工程]