摘要
注浆充填不仅是应对深部开采围岩高应力大变形行之有效的方法,也是实现绿色低碳开采的关键技术。因此针对注浆加固工艺,设计不同负压压力注浆加固单轴压缩试验,探究负压注浆加固效果,结合多孔介质浆液流动效应,确定负压注浆浆液扩散模式,归纳出注浆加固体力学特性影响因素,研究不同负压压力引起的试件物理参数变化,探讨负压注浆加固试件应力-应变曲线的4个阶段,分析注浆加固体的强度特征及变形趋势,总结负压注浆加固后的3种破坏形态,阐明负压注浆过程中的多方面作用机制。结果表明:破碎岩体实际情况与理论相左,负压注浆需考虑4个方面作用力,其加固力学特性受4个因素影响;随负压压力的增加,试件发生水灰比、孔隙率和掺入量的三重改变,试件密度整体呈先上升后下降趋势,表现出3个阶段特征,且试件孔隙率持续下降;负压注浆加固试件应力-应变曲线呈现出4个阶段变化,试件强度均值曲线与弹性模量均值曲线表现为先上升后下降趋势,而轴向应变均值曲线则先下降后上升,确定负压压力60 kPa为负压注浆加固压力阈值;负压注浆压力的不同,使得试件内部结构产生差异,最终表现为三类破坏形态;负压注浆过程受4个方面因素共同作用,既要考虑浆液水化反应,又要思考固液交界面液桥特性,同时还要兼顾注浆过程中的孔隙变化及真空脱水效应。研究成果对于注浆加固工艺改进有较大的参考价值,为煤炭清洁高效稳定开采提供理论及试验依据。
Grouting is not only an effective method to address the high stresses and large deformations of surrounding rock in deep mining,but is also a key technology for green and low-carbon mining.Accordingly,this study conducted uniaxial compression tests on grouting reinforcement with different negative pressure pressures to explore the reinforcement effect of negative pressure grouting.It analyzed the effects of slurry flow effect of porous media on the mechanical properties of grouting and solid.Moreover,we investigated the relations of the physical parameters,specimen's strength,deformation in different samples under different negative pressures and examined the sample failure modes drawing the following conclusions based on the present compression test results.First,the effect of the four forces on the negative pressure grouting results in the reinforcement mechanical properties being affected by four factors as the actual situation of the broken rock mass differs from the theory.Secondly,as the negative pressure is increased,a triple change in the water-cement ratio,porosity,and doping of the specimen occurs.The density of the specimen shows a trend of first increasing and then decreasing,exhibiting a three-stage character,with the porosity of the specimen continuing to decrease.Thirdly,the stress-strain curve of the specimen reinforced by negative pressure grouting shows four stages of change of which the strength and elastic modulus of the specimen showed a trend of first a rise and then a decrease,while the mean curve of the axial strain shows a first decrease and then a rise.It can be determined that the negative pressure of 60 kPa is the threshold value of negative pressure grouting reinforcement.Then,the difference between negative pressure grouting pressure makes the internal structure of the specimen different,and finally shows three types of failure modes.Finally,the negative pressure grouting process is affected by four factors.It is necessary to take into account not only the hydration reaction of the slurry,but also the characteristics of the liquid bridge at the solid-liquid interface,and at the same time the pore changes and vacuum dehydration effects during the grouting process.The results are of great reference to improve the grouting reinforcement process and provide a theoretical and experimental basis for clean,efficient and stable coal mining.
作者
吕鑫
杨科
方珏静
段敏克
王于
张寨男
LYU Xin;YANG Ke;FANG Juejing;DUAN Minke;WANG Yu;ZHANG Zhainan(State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan,Anhui 232001,China;Institute of Energy,Hefei Comprehensive National Science Center,Hefei,Anhui 230031,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2023年第S02期4174-4188,共15页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(52130402)
安徽省重点研究与开发计划项目(202104a07020009)
合肥综合性国家科学中心能源研究院重大培育项目(21KZS215)
关键词
采矿工程
注浆加固
负压注浆
破碎岩体
水化反应
真空脱水
mining engineering
grouting reinforcement
negative pressure grouting
broken rock mass
hydration reaction
vacuum dehydration
作者简介
吕鑫(1995-),男,2020年于河南理工大学矿业工程专业获硕士学位,现为博士研究生,主要从事矿山压力与岩层控制理论及治理方面的研究工作。E-mail:xin_lyu@qq.com
