Influence Factors of Strata Deformation Response Induced by Shield Tunneling in Thick Silty Clay Layer

[Objective] In thick silty clay layers, the disturbance caused by shield tunneling is affected by multiple factors such as strata conditions and construction parameters. Given the complexity of strata deformation, it is necessary to study the influence law of strata conditions and construction parameters on shield tunneling induced strata deformation. [Method] Taking a tunneling section of Suzhou Rail Transit Line 11 as an example, the stress-seepage coupling calculation of shield tunneling in saturated soil is carried out. Soil mechanical properties are calculated using the lower load surface constitutive model capable of considering pore correlation. Calculation results are analyzed and compared with the measured results. The influence of formation conditions (soil permeability coefficient) and construction parameters (face pressure, tunneling speed) on strata deformation during shield tunneling is analyzed, together with the factors sensitivity. [Result & Conclusion] Adopting the stress-seepage coupling calculation of the lower load surface constitutive model can well reproduce strata deformation response induced by shield tunneling; the increase of face pressure and tunneling speed will reduce the total ground settlement, while the greater the soil permeability coefficient, the greater the total land subsidence. The sensitivity of each influencing factor for strata deformation induced by shield tunneling is in the following order: face pressure sensitivity>soil permeability sensitivity>tunneling speed sensitivity.