超大直径泥水盾构在海底高强度花岗岩基岩凸起地层（饱和单轴抗压强度41.7～214.0 MPa）掘进过程中，面临破岩效果不确定、掘进参数难以选取、刀具异常损坏、换刀频率高、风险大等施工难题。为解决这些难题，首先，对爆破预处理和直接掘进2种工法的优缺点进行对比分析，并通过室内滚刀破岩试验验证刀间距为100 mm时破岩的可行性，提出滚刀不过载前提下的贯入度控制指标；
然后，结合现场掘进试验总结出“控制贯入度为主、转速为辅，严控刀盘转矩波动”的掘进参数控制原则，确定超大直径泥水盾构直接掘进通过基岩凸起段的刀盘转速为1.0 r/min，贯入度为3 mm/r； 最后，应用刀具监测及管理措施，使超大直径泥水盾构直接顺利掘进通过高强度基岩凸起地层。
When superlarge diameter slurry shield tunneling in a
subsea tunnel with a highstrength 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 superlarge diameter
shield directly tunneling through bedrock protrusion section is determined. The
superlarge diameter shield successfully passed through
the highstrength bedrock protruding stratum after
cutting tool monitoring and management.
