Analysis on Diffusion Law of Synchronous Grouting Slurry in Shield Tunnel Based on Random Fracture Distribution of Surrounding Rock
Research purposes:Synchronous grouting in shield tunnel construction is a primary factor for segment floating and misalignment during the construction phase,particularly in geological strata characterized by poor self-stabilization and abundant fractures.This study aims to investigate the filling and diffusion behavior of synchronous grouting slurry within the tail clearance of a shield tunnel and its surrounding rock.A transient model of slurry permeability incorporating the random fracture distribution of the surrounding rock was established against the backdrop of the Guangzhou Metro Line 18,intending to provide theoretical guidance for the synchronous grouting process in shield tunneling.Research conclusions:(1)The grouting slurry can completely fill the shield tail clearance within 20 seconds post-grouting,subsequently permeating into the strata along the fractures with a seepage velocity that decreases over time.(2)Due to the presence of grouting pressure,the pore water pressure around the segment significantly exceeds that at the same depth further from the tunnel area.(3)The Darcy velocity within the fractures is considerably higher than in the continuous stratum,with permeating fractures serving almost exclusively as the conduit for groundwater flow.(4)The Darcy dynamic velocity within the strata is sensitive to both the porosity and permeability coefficients.(5)The research findings are applicable to the field of grouting engineering in shield tunneling.
subway tunnelsynchronous groutingrandom fractureslurry diffusiontransient model
万方数据
维普
