KRCD pile execution chart necessary to analyze the system and get bearing capacity feedback. After reviewing the pile load test results, a socket length based on the drilling speed was defined in correspondence with the drilling logs from the test piles. Further piling works were controlled by dynamic pile tests to verify the bearing capacity. The model used to analyze the dynamic testing was calibrated by the static load tests executed at the beginning of the project. Conclusion The KRCD method applied with double rotary heads allowed the most sensitive drilling in difficult soil conditions for the Oslo S project. Because both rotary heads worked independently, the drill bit could be positioned inside the casing to avoid Oslo S, with developing cut and cover and top down tunnels behind backflow facility's filter press (yellow rectangles) and water pump and mixing stations (lower left). DEEP FOUNDATIONS * NOV/DEC 2020 * 19