Multi-type and multi-size split barrel coring technology were used in the hole WFSD-1 of Wenchuan earthquake fault scientific drilling project to ensure high core recovery rate and keep the cores in original state even in very complicated formation conditions.

The technique is to use the 89-mm-wider socket tubes as drilling rods and make holes by the single-action twin-pipe drilling tools, which can ensure the perpendicularity of boreholes and the percentage recovery of concrete cores in the construction of bridge piers.