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<p>With accelerating urbanization and increasing demand for metro transportation, shield tunneling in sandy pebble stratum faces challenges as traditional continuum methods fail to accurately simulate discrete particle behavior, necessitating a combined approach of model testing and discrete element simulations to optimize tunneling parameters and control surface deformation. This study investigates the dynamics of shield tunneling in sandy pebble stratum through an integrated approach combining laboratory-scale model tests, discrete element method (DEM) simulations, and field monitoring validation. A 1:20 scaled experimental apparatus was developed to simulate earth pressure balance (EPB) shield tunneling under 1&#xa0;g conditions. Controlled experiments systematically analyzed the effects of shield advancement speed and screw conveyor speed on surface deformation and earth pressure evolution. DEM simulations analyzed soil–cutter interactions, particle displacement, and disturbance mechanisms. Field measurements confirmed the accuracy of the model tests and DEM modeling. The results show that shield advancement speed transitions surface response from settlement to heave, while screw conveyor speed inversely modulates chamber pressure. Field monitoring revealed that post-excavation settlement accounts for 50–85% of total deformation, with influence zones confined to 0.5–1 time the tunnel diameter. DEM results quantified the impact of cutterhead rotation on torque, muck discharge efficiency, and soil disturbance, demonstrating that higher speeds enhance excavation efficiency but compromise face stability. This research advances practice al strategies for optimizing EPB shield parameters to mitigate surface displacement and ensure excavation stability.</p>

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Experimental and DEM simulation study on the disturbance of sandy pebble stratum by shield tunneling

  • 期刊论文

  • 发表日期：

    2025年3月29日

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  • Qianwei Xu,
  • Jinli Xie,
  • Weixing Wang,
  • Lianyang Zhang,
  • Yuanhai Li,
  • Hehua Zhu

摘要

With accelerating urbanization and increasing demand for metro transportation, shield tunneling in sandy pebble stratum faces challenges as traditional continuum methods fail to accurately simulate discrete particle behavior, necessitating a combined approach of model testing and discrete element simulations to optimize tunneling parameters and control surface deformation. This study investigates the dynamics of shield tunneling in sandy pebble stratum through an integrated approach combining laboratory-scale model tests, discrete element method (DEM) simulations, and field monitoring validation. A 1:20 scaled experimental apparatus was developed to simulate earth pressure balance (EPB) shield tunneling under 1 g conditions. Controlled experiments systematically analyzed the effects of shield advancement speed and screw conveyor speed on surface deformation and earth pressure evolution. DEM simulations analyzed soil–cutter interactions, particle displacement, and disturbance mechanisms. Field measurements confirmed the accuracy of the model tests and DEM modeling. The results show that shield advancement speed transitions surface response from settlement to heave, while screw conveyor speed inversely modulates chamber pressure. Field monitoring revealed that post-excavation settlement accounts for 50–85% of total deformation, with influence zones confined to 0.5–1 time the tunnel diameter. DEM results quantified the impact of cutterhead rotation on torque, muck discharge efficiency, and soil disturbance, demonstrating that higher speeds enhance excavation efficiency but compromise face stability. This research advances practice al strategies for optimizing EPB shield parameters to mitigate surface displacement and ensure excavation stability.