短語詞組短語spiral easement curve 螺旋緩和曲線;螺旋型緩和曲線spiral curveclothoid curve 螺旋曲線spiral transition curve 緩和曲線;螺旋型緩和曲線Spiral -curve cut 活旋切法spiral easement curve west bank 螺旋緩和曲線part of spiral curve 部分回旋線incomplete spiral curve 不完全緩和曲線nth spiral curve n 次回旋線spiral curve location [測]緩和曲線測設(shè) 返回 spiral curve