What is a String Line?

Method of chord deflection dis-tance curve setting method is a method to stake out the point position. It is to double the chord length between two adjacent points on the circular curve, and the calculated deviation from f
R
Yi. The distance between the flow stones and the distance d is measured, and the points on the curve are measured by the distance intersection method. He Ming can be calculated

Chord offset method

Right!

Method of chord deflection dis-tance curve setting method is a method to stake out the point position. It is to double the chord length between two adjacent points on the circular curve, and the calculated deviation from f
R
Yi. The distance between the flow stones and the distance d is measured, and the points on the curve are measured by the distance intersection method. He Ming can be calculated

Let d, and d meet at point 1 at ZY and 1 'and extend to 2', then at point 1 and 2 'at intersection 2. This method is sometimes used in the excavation of curved tunnels.
d,