摘要
为探究富水粉细砂层中盾尾同步注浆浆液扩散规律,将浆液扩散过程中滤饼开始生成的时间作为浆液渗透扩散与压密扩散转折点,建立考虑渗滤效应的浆液渗透扩散理论公式及浆液压密扩散影响半径理论公式,并通过自主研发设计的盾尾同步注浆系统进行相似模型试验,验证理论公式合理性。结果表明:(1)在富水粉细砂层中,浆液扩散规律与常规单一扩散模式不同,呈渗透-压密两阶段;(2)滤饼的作用在于将以孔压形式存在的浆液压力转化为有效应力作用于土体骨架,滤饼开始生成后,浆液扩散模式由渗透扩散转变为压密扩散;(3)由浆液压力有效应力转化率曲线变化规律可知,注浆压力越大,滤饼开始生成时间越短,即浆液渗透扩散持续时间越短;(4)随着注浆压力增大,浆液压密扩散阶段影响半径也变大,通过试验及理论计算确定注浆压力为0.4 MPa时对地层扰动范围约为1倍隧道开挖轮廓。该研究成果可为富水粉细砂层中盾尾同步注浆施工提供理论支撑。
In order to explore the slurry diffusion law of shield tail synchronous grouting in water-rich fine sand layer,start time of filter cake generation in the process of slurry diffusion is taken as the turning point of slurry permeation diffusion and compaction diffusion,and the theoretical formula of slurry permeation diffusion considering permeation effect and the theoretical formula of influence radius of slurry compaction diffusion are established.The similarity model test is carried out by the self-developed shield tail synchronous grouting system to verify the rationality of the theoretical formula.The results show that:(1)In the water-rich fine sand layer,different from the conventional single diffusion mode,the slurry is diffused in two stages of permeation-compaction.(2)The function of filter cake is to convert the slurry pressure in the form of pore pressure into effective stress acting on the soil skeleton,and after the filter cake begins to form,the slurry diffusion mode changes from permeation diffusion to compaction diffusion.(3)According to the change law of the effective stress conversion rate curve of the slurry pressure,the larger the grouting pressure,the shorter the time of filter cake formation,i.e.the shorter the duration of the slurry permeation diffusion.(4)With the increase in grouting pressure,the influence radius of slurry compaction diffusion stage also increases,e.g.the disturbance range of the stratum is about one times the tunnel excavation contour when the grouting pressure is 0.4 MPa through experiments and theoretical calculations,.The research results can provide theoretical support for synchronous grouting construction of shield tail in water-rich fine sand layer.
作者
宋洋
王宏帅
李昂
王鑫
肖作明
苑强
SONG Yang;WANG Hong-shuai;LI Ang;WANG Xin;XIAO Zuo-ming;YUAN Qiang(School of Architecture and Transportation,Liaoning University of Engineering and Technology,Fuxin,Liaoning 123000,China;School of Civil Engineering,Liaoning University of Engineering and Technology,Fuxin,Liaoning 123000,China;CCCC Third Highway Engineering Co.,Ltd.,Beijing 101304,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2023年第5期1319-1329,共11页
Rock and Soil Mechanics
基金
国家自然科学基金(No.51974146,No.52174078)
辽宁省高等学校创新人才支持计划资助项目(No.21-1071)
辽宁省自然科学基金(No.2019-ZD-0042)。
关键词
盾尾同步注浆
渗滤效应
渗透扩散
压密扩散
滤饼开始生成时间
相似模型试验
shield tail synchronous grouting
permeation effect
permeation diffusion
compaction diffusion
start time of filter cake generation
similarity model test
