砂质土体脉动注浆浆-土耦合动力响应分析  

Dynamic response analysis of slurry-soil coupling in sandy soil based on pulsating grouting

作　　者：窦金熙 张贵金[1,2] 张熙 范伟中 宋伟 DOU Jin-xi;ZHANG Gui-jin;ZHANG Xi;FAN Wei-zhong;SONG Wei(School of Hydraulic and Environmental Engineering,Changsha University of Science and Technology,Changsha,Hunan 410114,China;Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province,Changsha University of Science and Technology,Changsha,Hunan 410114,China)

机构地区：[1]长沙理工大学水利与环境工程学院,湖南长沙410114 [2]长沙理工大学水沙科学与水灾害防治湖南省重点实验室,湖南长沙410114

出　　处：《岩土力学》2021年第12期3315-3327,共13页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51279019);中国电力投资集团公司重大科技计划项目(No.2011-036-WLDKJ-X);湖南省重大水利科技项目(XSKJ2018179-32)。

摘　　要：脉动注浆作为解决松散土体注浆的新工艺,尽管已经得到一定应用,但脉动荷载作用下浆-土耦合的动力响应研究,远滞后于工程实践。基于脉动注浆原理,设计了一套脉动注浆监测响应系统,设定不同脉动周期压力和土体孔隙比,研究不同脉动周期荷载作用砂质土体的响应规律;依托COMSOLMultiphysics平台结合MATLAB,二次开发了适用于模拟脉动注浆浆-土耦合应力-应变的程序;通过物理试验对比现有注浆地层响应理论,验证了数值模拟适用性。研究结果表明:当脉动压力增大,土体的孔隙比不变时,骨架力承担脉动应力传递速率增快;脉动频率越大,土体内部应力越大;脉动压力会破坏恒载作用下土体形成的强弱力链,导致应力传递均布;土体的孔隙比越大,土体越松散,脉动频率越大对于浆液在土体内部运移越有利。脉动注浆相比于稳压注浆会导致应力区域集中,应力区域集中造成的浆液渗透与挤密注浆,有利于降低注浆过程地层抬升位移;相比稳压注浆的浆液易沿小主应力或者地层缺陷处浆液持续劈裂,脉动注浆浆液扩散更可控。数值模拟方法为不同脉动施工参数、地层条件以及注浆材料下,浆液扩散规律研究提供了新思路,研究结论可为工程实践提供较强的指导意义。As a new grouting technology,pulsating grouting has been successfully applied to solve the problem of loose soil grouting.However,the dynamic response of slurry-soil coupling under pulsating load lags far behind the engineering practice.Based on the theory of pulsating grouting,a monitor system of pulsating grouting was designed.The response laws of sandy soil under different pulsating periodic loads were investigated by setting different pulsating periodic pressures and soil porosity ratios.Then through COMSOL Multiphysics platform and MATLAB,a program for simulating the stress-strain of slurry-soil coupling was developed.The applicability of numerical simulation was verified by comparing the existing grouting response theory with physical tests.The results show that when the pulsating pressure increases and the pore ratio of soil remains constant,the transfer rate of the pulsating stress borne by the skeleton force increases rapidly.The higher the pulsation frequency,the greater the soil stress.The fluctuating pressure will destroy the strong and weak force chain formed by the soil under constant load,resulting in the uniform stress transfer.The larger the pore ratio,the looser the soil and the higher the pulsation frequency,the more favorable the slurry migration in the soil.Compared with stable pressure grouting,pulsating grouting can lead to the stress concentration.Correspondingly,the slurry penetration and compaction caused by the stress concentration are beneficial to reduce the formation uplift displacement in the grouting process.Compared with stable pressure grouting,by which the grout is easy to split continuously along the small principal stress or formation defect,the grout diffusion induced by pulsating grouting is more controllable.In addition,the numerical simulation method provides a new idea for the slurry diffusion laws under different pulsating construction parameters,formation conditions and grouting materials.The research conclusions can provide a strong guiding significance for engineering

关 键 词：脉动注浆 砂质土 动力响应 黏土-水泥浆液 浆-土耦合 

分 类 号：TU470[建筑科学—结构工程]