摘要
冰碛层隧道围岩的地质组成情况复杂,整体胶结性差,结构不均匀,隧道在开挖过程中易出现围岩垮塌、涌水等问题。因此,以硅酸盐水泥为主材料,添加氧化镁、黄原胶、膨润土及水玻璃进行组分优化,通过析水率试验、凝固试验、流动度试验、力学试验、膨胀率试验及抗渗性能试验,研究一种适用于冰碛层围岩注浆条件的新型水泥基注浆材料,并分析注浆材料的微观形貌与固结机理。结果表明:新型注浆材料孔隙和缝隙基本被充填,结构紧密,抗渗性能相对较好。向材料中引入Mg^(2+)可形成Mg(OH)_(2)晶体以填补材料微孔结构,完善材料抗渗机制。大量纤维状水化硅酸钙(C—S—H)凝胶将钙矾石(AFt)、Ca(OH)_(2)、Mg(OH)_(2)等晶体和黄原胶螯合体胶结包裹成整体,可大幅提高材料抗渗能力。通过现场试验,验证了注浆材料的优良性能,材料可有效固结冰碛松散地层,确保隧道开挖安全。
The geological composition of the surrounding rock of the moraine layer tunnel is complicated,the overall cementation is poor,the structure is not uniform,and the surrounding rock collapse and water gusher are easy to occur during the tunnel excavation.Therefore,Portland cement was used as the main material,and magnesium oxide,xanthan gum,bentonite and water glass were added to optimize the components.A new cement-based grouting material suitable for the grouting conditions of the surrounding rock of the moraine layer was studied through the water out rate test,solidification test,fluidity test,mechanical test,expansion rate test and permeability resistance test,and the micro-morphology and consolidation mechanism of the grouting material were analyzed.The results show that the pores and crevices of the new grouting material are basically filled,the structure is tight,and the impermeability is relatively good.The introduction of Mg^(2+) into the material can form Mg(OH)_(2) crystals to fill the micropore structure of the material and improve the anti-permeability mechanism of the material.A large number of fibrous C—S—H gels cement AFt,Ca(OH)_(2),Mg(OH)_(2) crystals and xanthan gum chelates into a whole,which greatly improve the material's permeability resistance.The excellent performance of the grouting material is verified by the field test.The material can effectively consolidate the loose stratum of the moraine and ensure the safety of tunnel excavation.
作者
尚强
韦猛
廖峰帆
郑宇
申聪
张世豪
刘语诗
王志文
SHANG Qiang;WEI Meng;LIAO Feng-fan;ZHENG Yu;SHEN Cong;ZHANG Shi-hao;LIU Yu-shi;WANG Zhi-wen(School of Environment and Civil Engineering,Chengdu University of Technology,Chengdu 610051,China;State Key Laboratory of Geological Hazard Prevention and Geological Environment Protection,Chengdu 610051,China)
出处
《科学技术与工程》
北大核心
2024年第17期7073-7081,共9页
Science Technology and Engineering
基金
国家自然科学基金(42072342)。
关键词
冰碛层
注浆材料
固结机理
耦合作用
moraine sheet
grouting material
consolidation mechanism
coupling action
作者简介
第一作者:尚强(1999-),男,汉族,四川江油人,硕士研究生。研究方向:隧道与地下工程。E-mail:331663088@qq.com;通信作者:韦猛(1969-),男,土家族,湖北松滋人,博士,教授。研究方向:隧道与地下工程。E-mail:1467109408@qq.com。
