The 14# main pier of the Chongqing Qianjiang Apengjiang Railway Bridge. In this small construction area, our company invested one SR385 rotary excavator and 9 10-16 ton percussion drills to construct 36 piers with a diameter of 2800mm and a pile length of 86m~98m. Rock-socketed pile construction. In order to solve the construction of the super-long piles of the 14# and 15# main bridge piers, our company has adopted the combined construction technology of rotary excavator + percussion drilling rig after the demonstration of quality, safety and economy.