泥水平衡盾构用海水泥浆的改性试验研究  

Experimental study on improved seawater slurry for slurry shield

作　　者：杨振兴 陈健[2] 孙振川 游永锋 周建军 吕乾乾 YANG Zhen-xing;CHEN Jian;SUN Zhen-chuan;YOU Yong-feng;ZHOU Jian-jun;Lü Qian-qian(State Key Laboratory of Shield Machine and Boring Technology,China Railway Tunnel Group Co.,Ltd.,Zhengzhou,Henan 450001,China;State Key Laboratory Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430001,China;China Railway Tunnel Stock Co.,Ltd.,Zhengzhou,Henan 450001,China)

机构地区：[1]中国中铁隧道局集团有限公司盾构及掘进技术国家重点实验室,河南郑州450001 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430001 [3]中国中铁隧道股份有限公司,河南郑州450001

出　　处：《岩土力学》2020年第2期501-508,共8页Rock and Soil Mechanics

基　　金：国家高技术研究发展计划(863计划)(No.2012AA041802);湖北省技术创新重大项目(No.2017ACA186);中国中铁科技开发计划(专项Ⅱ类-03),中隧集团科研创新计划(隧研合2017-05)。

摘　　要：由于海水中富集大量可溶性盐类及各种金属离子成分,利用海水配置的海水泥浆具有相对密度大、胶体率低、稳定性差、失水量高等特点,不能满足泥水平衡盾构施工要求。为实现对海水泥浆改性以达到利用海水泥浆维持开挖面稳定,降低穿江越海盾构施工成本,选用CMC(羧甲基纤维素钠)、纤维素PAC(聚阴离子纤维素)、聚丙烯酸铵等8种添加剂进行海水泥浆性质变化试验,优选出对海水泥浆改性明显的添加剂,并分析优选添加剂掺入量和时间对海水泥浆性质的影响规律。同时,基于优选的添加剂CMC,利用泥膜形成试验平台进行改性海水泥浆地层渗透试验。研究表明:不同添加剂对海水泥浆性质变化差异较大,增黏剂PAC、CMC对海水泥浆的改性效果稍好,24 h离析出现浑浊层、混合层、絮凝沉淀层。海水泥浆对地层渗透的滤水量大于改性海水泥浆,泥皮也稍厚,但呈稀疏状态。可以推测,添加剂中和部分海水成分,呈絮凝沉淀,多余添加剂表现出对淡水泥浆的增稠作用。Due to the enrichment of a soluble salts and various metal cation components in seawater,seawater slurry shows large specific gravity,low colloidal rate,poor stability and high water loss,and does not meet the requirements of slurry shield construction.In order to modify the seawater slurry to maintain the stability of the excavation surface and reduce the construction cost of the shield tunnel,eight additives,such as CMC,cellulose PAC,and ammonium polyacrylate,etc.,were used to test the properties of seawater slurry.The additives which modified the seawater were selected,and the influence law of the additives amount and time on the properties of the seawater slurry was analyzed.At the same time,the modified seawater slurry formation penetration test was carried out based on the preferred additive CMC using a mud film formation test platform.Results show that different additives have significant differences in the properties of seawater slurry.The cellulose PAC and CMC have better modification effect on seawater slurry.The turbid layer,mixed layer and flocculated sediment layer appear in 24 h.The amount of water filtered by the seawater slurry to the formation is greater than that of the modified seawater slurry,and the slurry skin is slightly thicker,but it is sparse.It can be speculated that the additive neutralizes part of the seawater component and flocculates and precipitates,and the excess additive exhibits a thickening effect on the pale cement slurry.

关 键 词：海底盾构隧道 泥浆改性 泥浆渗入试验 成膜质量 胶体率 

分 类 号：TU352.11[建筑科学—结构工程]