摘要
红粘土是一种特殊土,具有高液塑限、高粘聚力、富含粘土矿物以及复杂的微观结构等特点。土压平衡盾构在穿越红粘土地层过程中,常遇到刀盘结泥饼、土舱闭塞、排土不畅等问题。为此,文章以武汉市雄楚大道新建高压电力通道工程土压平衡盾构掘进穿越红粘土地层为背景,研制了一种由阴离子表面活性剂A、非离子表面活性剂B和抗粘添加剂C复配而成的新型改良添加剂,通过性能试验、搅拌试验、坍落度试验、稠度试验、液塑限联合测定试验评价了土体改良的效果,得到了含水率为40%及改良剂注入率为30%的理想土体改良指标。通过对比试验表明,研制的新型改良剂对红粘土土体的改良效果较好,所得结果可为红粘土地层盾构施工中的土体改良提供参考。最后文章分析了添加剂改良红粘土的机理,得出红粘土遇水易膨胀、易泥化、强粘滞性是盾构施工过程中“结泥饼”的根本原因。
Red clay is a kind of special soil which has the characteristics of high liquid plastic limit, high cohesive force, high clay mineral content, complex microstructure and so on. Mud cake at cutterhead, blocking in earth chamber and poor soil mucking are often encountered during the shield construction in red clay. Based on the EPB shield adopted in a newly built high-voltage cable tunnel on the Xiongchu avenue passing through red clay, a modified additive compounded with anionic surfactant A, nonionic surfactant B and bond-resistance additive C was developed,and the effect of soil mass conditioning was evaluated by performance test, mixing test, slump test, consistency test and liquid-plastic limit combination test, the ideal parameters for conditioning of soil mass are water content of 40%and 30% of additive injection rate. Contrast test indicates that good effect of red clay conditioning was obtained with this modified additive. The mechanism of red clay conditioning by additive was analyzed, and it is found that radical reasons for mud cake generated during shield construction are the red clay which is liable to have argillization and expansion upon meeting water and has strong glutinousness.
作者
蔡兵华
李忠超
余守龙
吕斌泉
王方艳
CAI Binghua;LI Zhongchao;YU Shoulong;LV Bingquan;WANG Fangyun(Wuhan Municipal Construction Group Co., Ltd., Wuhan 430074;Department of Engineering, China University of Geosciences,Wuhan 430074)
出处
《现代隧道技术》
EI
CSCD
北大核心
2019年第5期218-227,共10页
Modern Tunnelling Technology
基金
武汉市市政建设集团有限公司科技计划项目（201609）
关键词
土压平衡盾构
红粘土
土体改良
室内试验
含水率
泡沫注入率
改良机理
Earth pressure balance shield
Red clay
Soil mass conditioning
Laboratory test
Water content
Foam injection rate
Conditioning mechanism
