Research on the Sensitivity of Factors Affecting the Stability of Slurry Shield Excavation Face and Control Parameter Optimization

Disturbance of the excavation surface caused by mud-water shield tunneling causes formation settlement. The main influencing factors are tunnel depth, mud weight, cutter opening ratio, propulsion speed, grouting pressure, soil properties (including cohesion and internal friction angle), and other engineering measures during construction. Based on the orthogonal test principle, the finite difference software FLAC3 D was used to study the global sensitivity of the influencing factors, and the tunneling parameters were also discussed. The results show that the internal friction angle has the most significant influence on the settlement index, followed by the propulsion speed, cohesion and mud weight, which are the main influencing factors. However, the influence of tunnel burial depth, cutter head opening ratio and grouting pressure on settlement is basically the same, which is a secondary influencing factor. In actual construction, the shield advancement speed and mud weight mainly control the ground settlement, while the mud weight and cutterhead opening ratio mainly affect the stability of the shield itself.