根据宝成、成昆、川黔等既有线改造的具体情况,对行车速度、二线位置、设计坡度及建设方法等问题提出了一些看法及设计中应注意的问题。

Based on the par ticular si tuatio ns o n the reform o f the existing Bao-Cheng, Cheng- Kun and Chua n-Qian Rai lway s, the a uthor proposes sev eral opinions concerned wi th the running speed, po si tio n of No. Ⅱ rai lw ay line, desig n g radient , const ruction method, etc. The problems w hich sho uld be taken inte a ttention are also pro posed.