不同泥浆渗透模式下形成泥膜的闭气效果探讨  

Airtightness of Filter Cakes Formed under Different Slurry Infiltration Modes

作　　者：闵凡路[1,2] 赵小鹏 朱伟[1,2] 张宁[1,2] 

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,南京210098 [2]河海大学土木与交通学院,南京210098 [3]中交隧道工程局有限公司,北京100088

出　　处：《现代隧道技术》2015年第4期68-73,共6页Modern Tunnelling Technology

基　　金：国家重点基础研究发展计划(973计划)(2015CB057803);国家自然科学基金项目(51408191);江苏省疏浚与泥处理利用国家工程技术研究中心培育点(BM2013013);中央高校基本科研业务费专项资金(2015B06014)

摘　　要：文章针对泥水盾构带压开舱时开挖面泥膜的闭气性问题，以南京纬三路过江通道穿越的砂卵石地层为实验地层，通过自行研制的泥膜气密性装置，开展了不同泥浆渗透模式下形成泥膜的闭气试验。结果表明：泥浆向地层中渗透时，部分泥浆颗粒堵塞在地层的孔隙中，有效地降低了地层的渗透性；先以密度为1．05～1.07g/cm3的纯膨润土泥浆向地层中渗透，再以密度为1．15g／cm3以上的稠泥浆形成泥膜，比只以较稠的泥浆形成单纯的泥皮型泥膜的闭气时间长数倍以上。该研究对泥水盾构在高渗透性地层中带压开舱时的泥浆调整和泥膜方案具有重要的参考意义。Aiming at the airtightness of filter cakes on the excavation face during hyperbaric chamber intervention in slurry shield tunnelling, and using the sandy cobble stratum through which the Nanjing Weisan Road river- crossing tunnel passes as anexample, airtightness tests were carried out for filter cakes formed under different slurry infiltration modes by a self-developed airtightness apparatus. The results show that when the slurry infiltrates into the stratum, some of the mud particles plug the pores of the stratum and effectively reduce the permeability; if the stratum is first infiltrated by a pure bentonite slurry with a density of 1.05-1.07g/cm3 and then the filter cake is formed by a slurry with a density above 1.15g/cm3, the period of airtightness will be several times longer than that of the filter cake only formed by the denser slurry. This study plays a significant role in slurry adjustments and filter cake schemes for slurry shields during hyperbaric interventions in highly permeable strata.

关 键 词：泥水盾构 砂卵石地层 带压开舱 泥膜 闭气时间 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]