富水砂层宾汉浆液柱形渗透扩散模型及其试验研究  

A cylindrical permeation and diffusion model for Bingham grout in water-rich sand layers and its experimental research

作　　者：王雪松 程桦[1,2,3] 姚直书[1] 荣传新[1] 谢鲍 WANG Xuesong;CHENG Hua;YAO Zhishu;RONG Chuanxin;XIE Bao(School of Civil Engineering and Architecture,Anhui University of Science&Technology,Huainan 232001,China;School of Resources and Environmental Engineering,Anhui University,Hefei 230601,China;Anhui Provincial Key Laboratory of Building Structure and Underground Engineering,Anhui Jianzhu University,Hefei 230601,China)

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南232001 [2]安徽大学资源与环境工程学院,安徽合肥230601 [3]安徽建筑大学建筑结构与地下工程安徽省重点实验室,安徽合肥230601

出　　处：《煤田地质与勘探》2024年第8期124-133,共10页Coal Geology & Exploration

基　　金：安徽理工大学高层次引进人才科研启动基金项目(2023yjrc15);国家自然科学基金项目(52174104);安徽省重点研发项目(202004a07020034)。

摘　　要：【目的】富水砂层灾害防控是困扰隧道、深大基坑等安全施工的重大难题,常通过袖阀管向地层内渗透注浆来提高强富水弱胶结砂质地层抗渗性和承载力,其注浆结石体近似为圆柱形。【方法】为探究砂层渗透注浆柱形扩散机理,首先构建考虑迂曲效应的宾汉浆液在砂层内渗透注浆的辐射管道流柱形扩散模型,然后研制一套砂层渗透注浆柱形扩散模型试验装置,开展不同颗粒级配被注砂土、不同注浆压力和不同水灰比水泥基浆液条件下的砂层渗透注浆试验,探究浆液扩散规律,最后结合试验结果验证理论合理性。【结果和结论】结果表明:当被注砂土粒径较小且黏性土含量较高时,注浆压力对扩散半径影响较小,浆液水灰比是影响注浆扩散形态的主控因素:此时若浆液水灰比较大,则渗滤效应不显著,注浆扩散半径较大且不容易发生串浆,但砂土颗粒之间的黏结强度沿径向逐渐降低;此时若浆液水灰比较小,则渗滤效应显著,浆液扩散较短距离后孔隙空间即被完全淤堵,土层交界面会成为浆液优势扩散面,出现串浆现象。当被注砂土粒径较大且黏性土含量较低时,低压稀浆与高压浓浆条件均可使浆液在砂土内充分扩散,但砂土孔隙分布的随机性、空间差异性和颗粒型浆液扩散的迂曲效应、渗滤效应会导致注浆结石体形状不是规则的圆柱体。浆液压力在扩散方向上衰减速度先快后慢,注浆扩散半径理论计算值比试验值大6.10%~10.97%,起始注浆压力理论计算值与试验值的相对误差为–0.48%~18.62%。研究成果可为砂层渗透注浆参数设计提供理论支撑与指导。[Objective]The disaster prevention and control for water-rich sand layers pose a major challenge to the safe construction of tunnels and deep foundation pits.Typically,the impermeability and bearing capacity of highly water-rich and weakly cemented sand layers are enhanced through permeation grouting via sleeve valve tubes,with resulting grouting concretions being approximately cylindrical.[Methods]To explore the cylindrical diffusion mechanism of permeation grouting in sand layers,this study constructed a cylindrical diffusion model of radial tube flow for the permeation grouting of Bingham grout in sand layers while considering the tortuosity effects.Subsequently,this study developed a set of experimental devices for the cylindrical diffusion model.Using these experimental devices,the experiments of permeation grouting in sand layers were conducted under different grain-size distributions of sandy soils to be grouted,varying grouting pressures,and cement-based grout with different water-to-cement ratios to explore the grout diffusion patterns.Finally,the theoretical rationality was verified based on the experimental results.[Results and Con-clusions]The results indicate that in the case of small grain sizes and high clay content of sandy soils to be grouted,the grouting pressure exerted minor impacts on the diffusion radius,while the water-to-cement ratio of grout served as the dominant factor controlling grouting diffusion morphologies.In this case,a high water-to-cement ratio of the grout was associated with insignificant infiltration effects,a large grouting diffusion radius,and low susceptibility to grout leaking.However,the bond strength among sandy soil grains gradually decreased along the radial direction.In contrast,a low water-to-cement ratio of grout corresponded to significant infiltration effects.Consequently,pores in sandy soils were completely blocked after grout diffusion for a short distance,with the interfaces between sandy soil layers becoming dominant grout diffusion surfaces,leading to grout

关 键 词：富水砂层 渗透注浆 宾汉浆液 柱形扩散 迂曲效应 渗滤效应 

分 类 号：TD266[矿业工程—矿井建设]