岩土工程学报2025，Vol.47Issue(7)：1432-1442,11.DOI:10.11779/CJGE20240251
密实细砂层地铁暗挖隧道新型超前加固材料性能及注浆参数研究
Performance and grouting parameters of new advanced reinforcement materials for underground tunnels with dense fine sand layers
摘要
Abstract
In order to mitigate the impact of advanced grouting reinforcement on the underground environment,it's necessary to employ low-pressure slow injection for grouting.The dense fine sand layer exhibits a tight structure and high clay content.Consequently,under low grouting pressure,the diffusion radius of the existing grouting materials is limited,leading to ineffective reinforcement of the tunnel face.Based on the principles of component activation and particle size optimization,the novel grouting material is developed using the ground granulated blast-furnace slag(GGBS),ultrafine fly ash(UFFA)and ultrafine Portland cement(UFPC)as the primary components,with the addition of an appropriate quantity of composite activating.Through the laboratory experiments,the characteristics of slurry fluidity,setting time and unconfined compressive strength of the novel grouting materials under the influences of varying mix ratios and contents of composite activator are investigated.The reinforcement effects of the Portland cement(OPC),UFPC and new grouting materials are compared and analyzed using a self-developed small pipe grouting full-scale test device.The diffusion characteristics and the change in the final grouting pressure under the influences of overburden load and water content are elucidated.The experimental results show that at a water-solid ratio of 1:1,a mass ratio of 4:2:4 for the GGBS,UFFA and UFPC,and a composite activator content of 4%,the new grouting material exhibits optimal slurry fluidity,controllable setting time and high stone body strength.When using the advanced small pipe grouting method for reinforcement,the OPC slurry diffuses in dense fine sand layer through compaction process,the UFPC slurry through compaction-splitting process and the new grouting material through permeation-splitting processes.The new grouting material exhibits superior diffusion and reinforcement properties,surpassing the UFPC,while the OPC demonstrates the least favorable characteristics in comparison.Furthermore,the new materials should maintain low-pressure grouting during the initial stage of the process to mitigate the risk of excessive grout-causing localized sand splitting and subsequent reinforcement failure.The final grouting pressure linearly increases with the increase of the overlying load and water content,with an increase of 50 kPa in the overlying load resulting in an approximate 50 kPa increase in the grouting pressure.A 2%increase in the water content leads to an increase of around 40 kPa in the grouting pressure.The research findings have certain guiding significance for the theoretical researches and engineering applications of grouting.关键词
地铁隧道/浅埋暗挖法/密实细砂层/小导管注浆加固/浆液扩散特性/注浆参数Key words
metro tunnel/shallow buried subterranean excavation method/dense fine sand layer/small pipe grouting reinforcement/slurry diffusion pattern/grouting parameter分类
建筑与水利引用本文复制引用
陈铖,来弘鹏,刘禹阳,朱新健..密实细砂层地铁暗挖隧道新型超前加固材料性能及注浆参数研究[J].岩土工程学报,2025,47(7):1432-1442,11.基金项目
国家自然科学基金面上项目(52278391,51978064) （52278391,51978064）
国家自然科学基金青年基金项目(51908051) （51908051）
中国博士后科学基金项目(2021M700534)This work was supported by the National Natural Science Foundation of China(Grant Nos.52278391,51978064),the National Natural Science Foundation for Young Scientists of China(Grant No.51908051),China Postdoctoral Science Foundation Project(Grant No.2021M700534). （2021M700534）
