遵照英明领袖华主席指示,各条战线都要“弄清楚自己战线的具体的工作路线,具体的方针、政策和方法。并且在实践中不断地加以改进和完善。使各条战线的工作沿着毛主席的革命路线更快地前进”。我们从总结自己实践经验入手,试图弄清混凝土桥梁标准设计的发展方针等问题,借以指导自己的工作。标准设计集中反映了一个国家的科技水平和当前的方针政策,是贯彻执行方针政策的有力工具。桥梁是铁路的一个重要组成部分,常常占整个线路造价的百分之15～20。其中,跨度8米到80米中小跨度桥梁又占桥梁总数的百 Following instructions from Chairman Hua, wise head, all fronts must “make clear their own concrete work routes, specific guidelines, policies and methods for their frontlines and constantly improve and perfect them in practice so that work on all fronts can be carried out along Chairman Mao’s revolutionary line moved faster. ” We start from summing up our own practical experience, trying to clarify the standard design of concrete bridges development guidelines and other issues, in order to guide their own work. Standard design reflects a country’s level of science and technology and the current guidelines and policies, is a powerful tool to implement the principles and policies. Bridges are an important part of railways and often make up 15-20% of the entire line. Among them, the span of 8 meters to 80 meters of small and medium-span bridges account for the total number of bridges