摘要
为降低土压平衡盾构在复合地层中掘进时进行渣土改良的工程成本,以广州地铁21号线朱村至象岭区间为工程依托,通过对粉质黏土和砾砂不同比例组合的渣土进行颗粒分析,计算得到复合地层的粒径分布曲线,并结合室内试验和现场测试研究混合渣土的流动状态和渗透性。结果表明:当复合地层中含有粉质黏土层时,粗粒土层渣土流动状态和渗透性有较大的改善,添加少量的气泡或者膨润土泥浆,渣土状态即可满足盾构掘进的要求。粉质黏土层的含量在30%~70%之间时,渣土能够达到良好的塑性流动状态。粉质黏土层的含量超过70%时,存在结泥饼的风险。
In order to reduce the engineering cost of muck improvement during the process of the excavation of Earth Pressure Balance(EPB)shield in composite stratum,based on the project of Guangzhou metro line 21 from Zhucun to Xiangling,the particle size distribution curve of composite stratum was calculated by particle analysis of different proportion combination residual soil of silty clay and gravel sand in this paper.Besides,combined with laboratory test and field test,the flow state and permeability of mixed residue soil were studied.The results show that when there is silty clay layer in the composite stratum,the flow state and permeability of the coarse-grained soil muck are greatly improved.Adding a small amount of bubbles or bentonite slurry,the muck state can meet the requirements of shield tunneling.When the content of silty clay is between 30%and 70%,the slag can reach a good plastic flow state.When the content of silty clay exceeds 70%,there is a risk of mud cake.
作者
钟小春
张洋
张露露
槐荣国
ZHONG Xiaochun;ZHANG Yang;ZHANG Lulu;HUAI Rongguo(College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China;The Fifth Bureau Corporation of China Railway,Guangzhou,Guangdong 518000,China)
出处
《河北工程大学学报(自然科学版)》
CAS
2020年第2期24-29,共6页
Journal of Hebei University of Engineering:Natural Science Edition
基金
国家自然科学基金资助项目(51678217,51378176)
浙江省自然科学基金资助项目(LQ18E080004)。
关键词
土压平衡盾构
渣土改良
复合地层
颗粒分析
EPB shield
muck improvement
composite stratum
particle size analysis