缓和曲线理论投点曲线长的直接求解公式

The Direct Solution for the Curve Length of a Theoretical Control Point on the Transition Curve

导出了隧道控制测量中缓和曲线理论投点曲线长的直接求解公式。此法避开了解高次方程，具有理论严谨、计算简捷的特点，用普通计算器即能实现。

The direct solution formula for the curve length of a theoretical control point on the transition curve is proposed,with the solution of high order equation being avoided. It can be easily used in the curve tunnel control survey to obtain the curve length of any theoretical point. This method is precise in theory and has advantage of simplicity.