随机裂隙围岩盾构隧道注浆浆液扩散规律  

Analysis on Diffusion Law of Synchronous Grouting Slurry in Shield Tunnel Based on Random Fracture Distribution of Surrounding Rock

作　　者：王新强 WANG Xinqiang(China Railway Construction Bridge Engineering Bureau Group Co.Ltd,Tianjin 300300,China)

机构地区：[1]中国铁建大桥工程局集团有限公司,天津300300

出　　处：《铁道工程学报》2024年第9期67-71,76,共6页Journal of Railway Engineering Society

摘　　要：研究目的:盾构隧道同步注浆是造成施工期管片上浮、错台的主要因素,尤其是在自稳能力较差与裂隙较多的地层。为探究同步注浆浆液在盾尾间隙与围岩的填充与扩散规律,本文以广州地铁18号线为背景,建立考虑围岩随机裂隙分布的浆液渗透瞬态模型,以期为盾构隧道同步注浆过程提供一定的理论指导。研究结论:(1)浆液在注浆后20 s内可以完全填充盾尾间隙,随后浆液会随着裂隙向地层中填充渗透,渗透速度随时间不断降低;(2)因注浆压力的存在,使得管片周围地层的孔隙水压力明显大于远离隧道区域相同埋深的地层;(3)裂隙中的达西速度明显大于连续地层,贯通裂隙几乎是地下水流通的唯一通道;(4)地层中的达西速度对地层的孔隙率以及渗透系数较为敏感;(5)本研究成果可应用于盾构隧道注浆工程领域。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.

关 键 词：地铁隧道 同步注浆 随机裂隙 浆液扩散 瞬态模型 

分 类 号：U455[建筑科学—桥梁与隧道工程]