一、前言 当前国内外公路桥梁都在朝着大跨径,深基,高墩,宽桥,轻型化,机械化方向发展。应该看到,随着林业建设的方针从过去以生产木材为主,转移到培育森林资源为主的目标上来,过去林区那种单车道桥梁的结构形式已远远不能适应发展的需要,因此必须作出相应的改变。 I. Preface At present, both domestic and international highways and bridges are moving towards large span, deep foundation, high pier, wide bridge, light-weight and mechanized direction. It should be noted that as the policy of forestry construction shifted from mainly producing wood to the goal of fostering forest resources in the past, the structure of the single-lane bridge in the past was far from being able to meet the needs of development. Therefore, Must make the corresponding change.