设于桥梁上方的新型棚洞研究

研究目的:结合内昆线喇叭溪棚洞地形、地质条件及既有构筑物现状对棚洞的结构方案进行研究比选,优化棚洞结构型式。研究方法:通过结构计算分析棚洞结构设计的控制因素,针对控制因素对棚洞结构方案进行研究比选,确定棚洞的结构方案。研究结果:通过系统的方案研究,最终选定了独立钢筋混凝土框架与简支梁组合的结构型式。本棚洞已于2002年6月修建完成,使用情况良好。研究结论:对于喇叭溪棚洞这种多次超静定结构,混凝土收缩徐变及降温引起的温度应力对结构设计起控制作用。通过采用本棚洞设计采用的独立钢筋混凝土框架与简支梁组合的结构型式,既可以保证棚洞结构的整体稳定性,又可以大大降低温度附加应力。

Study of the New Type Shed Tunnel on the Bridge

Research purposes: According to the terrain,geological conditions and the status of the existing structures,this paper discusses the alternative option of the shed hole structure in order to optimize the structural style of shed hole. Research methods:By using structural analysis to find the control factors in the design of the shed hole structure and aiming at these control factors to compare the several different shed hole structure designments,the better designment can be confirmed. Research results:Through systemic analysis,the style that a composite structure which is composed of independent reinforced concrete framework and simply supported beam is adopted.It has been constructed by June 2002 and it has been working well. Research conclusions:The Labaxi shed hole is a statically indeterminate structure,whose structure design is controlled by shrinkage creep of the concrete and the temperature stress as the temperature decreasing.The composite structure can not only guarantee the general stability of the shed hole but also reduce the temperature stress.