卵型曲线等距线的弦距法放样

Equidistance lines of spawn-liked curve chord-distance method for construction location

山区高等级公路中经常出现各种形式的曲线组合 ,其中卵形曲线最为复杂 .当道路中心线采用卵形曲线时 ,道路边线即卵形曲线的等距线却不是卵形曲线 ,给施工放样带来一定的困难 ,通过计算卵形曲线的弓高 ,采用弦距法放样道路边线 。

Compound curve is often used in high classes road of mountain terrian desigh,the most complex situatio of which is opawn liked curve.When the centre line of road is spiral curve,the edge lines(equidistance lines of centre line) are not spiral curves,which makes it difficult for construction location.If chord distance method is employed to solve the problem through calculating the height of segment,it will be accurate and convenient.