前言 在增建第二线时,线间距的计算是一项很繁琐的工作。以往多系采用“结合角图法”和“三角分析法”进行计算。前者精度太低,后者在圆曲线部分精度高,而在缓和曲线部分存在着误差。当既有曲线与设计左线(或右线)的切线互相不平行,或者两曲线的相互位置错动很大,例如既有曲线的第一缓和曲线与左线(或右线)曲线的第二缓和曲线对应时,这两 Preface When adding a second line, the calculation of line spacing is a tedious task. In the past, many departments used the “combined angle map method” and “triangular analysis method” for calculation. The former is too low in accuracy, while the latter is highly accurate in the circular curve, while there is an error in the easing curve. When the existing curve is not parallel to the tangent of the left line (or the right line) of the design, or the mutual positions of the two curves are greatly different, for example, the first curve of the existing curve and the curve of the left The two moderate curves correspond to these two