风化岩渣矿物成分对盾构壁后注浆体性能影响研究  

Study on the Influence of Mineral Compositions of Weathered Rock Mucks on the Performance of Backfill Grouting in Shield Tunnelling

作　　者：赵小鹏 李震 袁锐 李鹏飞 闵凡路[2,3] 张雷 ZHAO Xiaopeng;LI Zhen;YUAN Rui;LI Pengfei;MIN Fanlu;ZHANG Lei(China Communications Construction Company Tunnel Engineering Bureau Co.,Ltd.,Beijing 100102;Key Laboratory of Geomechanics and Embankment Engineering of the Ministry of Education,Hohai University,Nanjing 210098;College of Civil and Transportation Engineering,Hohai University,Nanjing 210098)

机构地区：[1]中交隧道工程局有限公司,北京100102 [2]河海大学岩土力学与堤坝工程教育部重点实验室,南京210098 [3]河海大学土木与交通学院,南京210098

出　　处：《现代隧道技术》2024年第4期283-290,共8页Modern Tunnelling Technology

基　　金：国家自然科学基金(52378394,52078189);中央高校基本科研业务费专项资金(B230201037).

摘　　要：在风化岩层中进行盾构掘进产生的岩渣矿物成分较为复杂,其对浆体性能的影响规律及机理尚不明确。依托南京和燕路过江通道工程,使用不同矿物粉末替换岩渣中细颗粒(<75μm),测试废弃风化岩渣替换商品砂配制的岩渣-硬性浆的基本性能,并结合XRD、SEM等微观试验,探究岩渣细颗粒中矿物成分对浆液性能影响机理。结果表明:石英对浆液流动度与稠度几乎没有影响,高岭石的掺入会显著降低浆液流动度与稠度,当商品砂完全被高岭土-岩渣替换时,浆液初始流动度损失约31%,稠度降低48%,高岭石含量是影响浆液流动性的主要因素;高岭石能够促进C-S-H凝胶与钙矾石的生成,缩短浆液凝结时间,平均缩短23.6%,生成的C-S-H相互搭接、黏结,填充孔隙,提高浆液强度;但高岭石含量过多时,生成的过量钙矾石会覆盖在水泥表面,阻止水泥进一步水化,从而降低浆体抗压强度。The mineral compositions of rock mucks generated in shield tunnelling in weathered rocks are complex,and its impact on grout performance is not well understood.Based on the Nanjing Heyan Road River Crossing Project,different mineral powders were used to replace fine particles(<75μm)in the rock mucks.The basic performance of rock muck-hard grout,prepared by replacing commercial sand with weathered rock muck,was tested.Microscopic tests such as XRD and SEM were conducted to explore the mechanism by which the mineral compositions of fine particles in rock muck affects grout performance.The results show that the quartz has almost no impact on grout fluidi⁃ty and consistency.The addition of kaolinite significantly reduces grout fluidity and consistency.When commercial sand is completely replaced by kaolinite-rock muck,the initial fluidity loss of the grout is about 31%,and the con⁃sistency decreases by 48%.The kaolinite content is the main factor affecting grout fluidity.Kaolinite can promote the formation of C-S-H gel and ettringite,shorten the grout setting time by an average of 23.6%.The produced C-S-H gel intertwines and bonds,fills into pores and increases grout strength.However,excessive kaolinite content will re⁃sult in the formation of excess ettringite,which will cover the cement surface and prevent further hydration,thereby reducing grout compressive strength.

关 键 词：风化岩层 废弃岩渣 壁后注浆 抗压强度 微观形貌 

分 类 号：U454[建筑科学—桥梁与隧道工程]