Abstract: When superlarge diameter slurry shield tunneling in a subsea tunnel with a highstrength granite bedrock protruding stratum (saturated uniaxial compressive strength of 41.7~214.0 MPa), problems such as uncertain rock breaking effect, difficult driving parameters selection, abnormal damage of cutters, frequent tool replacement, and high construction risk are always encountered. Therefore, a laboratory test is conducted on shield rock breaking to analyze the advantages and disadvantages of blasting pretreatment and direct excavation. The 100 mm cutter spacing is then verified, and the control index of penetration degree is proposed under the premise of ensuring no overload. Furthermore, a shield tunneling parameter control principle of "penetration control as main, speed control as assistance, and strict cutterhead torque fluctuation control" is summarized based on the field tunneling tests, and the cutterhead rotation speed of 1.0 r/min and penetration degree of 3 mm/r when superlarge diameter shield directly tunneling through bedrock protrusion section is determined. The superlarge diameter shield successfully passed through the highstrength bedrock protruding stratum after cutting tool monitoring and management.

Key words: subsea tunnel, superlarge diameter slurry shield, bedrock protruding stratum, silt formations, tunneling method[