| 砂土介质注浆渗透扩散试验与加固机制研究 |
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| 引用本文： | 沙飞,李术才,林春金,刘人太,张庆松,杨磊,李召峰.砂土介质注浆渗透扩散试验与加固机制研究[J].岩土力学,2019,40(11):4259-4269. |
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| 作者姓名： | 沙飞 李术才 林春金 刘人太 张庆松 杨磊 李召峰 |
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| 作者单位： | 山东大学 岩土与结构工程研究中心，山东 济南 250061 |
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| 基金项目： | 国家重点研发计划项目（No. 2016YFC0801604）；国家自然科学基金青年项目（No. 51909140）；中国博士后科学基金资助项目（No. 2018M642658）。 |
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| 摘 要： | 设计了一套可视化砂土介质恒压注浆渗透扩散与加固模拟试验装置。选用普通硅酸盐42.5水泥（OPC）、超细硅酸盐水泥（MC）、超细硫铝水泥（MSAC）及自主研发材料（EMCG），对砂土多孔介质进行了注浆渗透扩散与加固试验。研究了细砂土体不同浆液、注浆压力工况下扩散距离、注浆量随时间变化规律，以及不同浆液、砂样级配及注浆压力对加固效果影响。采用极差分析法确定了加固效果主控因素，获得了加固体宏观破坏模式，通过SEM分析了岩-浆界面微观加固模型，揭示了不同材料加固效果差异的本质原因。研究结果表明：注浆材料与颗粒质量分数主导着细砂土体可注性，注浆压力对可注性提高程度不大，EMCG可注性最强，MC、MSAC次之，OPC最差；在完全可注情况下，砂样级配越细，加固体强度改善效果越明显；EMCG材料加固体7、28 d强度明显高于MSAC、MC、OPC加固体；EMCG的7 d加固体强度达到28 d参数70%以上；注浆材料主导着注浆加固效果，EMCG对不同级配砂土体注浆加固效果显著优于其他水泥类材料，OPC最差；注浆后EMCG浆-岩界面生成的致密C-S-H凝胶体能够有效提高胶结强度。最后从注浆材料选型、注浆过程控制、钻孔布置方面对砂土层渗透注浆设计方法提出了工程治理改进建议。
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| 关 键 词： | 砂土多孔介质 注浆模拟试验 渗透扩散 注浆材料 加固效果 岩-浆加固机制 |
| 收稿时间： | 2019-01-21 |
Research on penetration grouting diffusion experiment and reinforcement mechanism for sandy soil porous media |
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| SHA Fei,LI Shu-cai,LIN Chun-jin,LIU Ren-tai,ZHANG Qing-song,YANG Lei,LI Zhao-feng.Research on penetration grouting diffusion experiment and reinforcement mechanism for sandy soil porous media[J].Rock and Soil Mechanics,2019,40(11):4259-4269. |
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| Authors: | SHA Fei LI Shu-cai LIN Chun-jin LIU Ren-tai ZHANG Qing-song YANG Lei LI Zhao-feng |
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| Institution: | Geotechnical and Structural Engineering Research Center, Shandong University, Jinan, Shandong 250061, China |
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| Abstract: | A novel visualizing constant pressure penetration grouting diffusion and reinforcement simulation test device was designed. The ordinary Portland cement 42.5 (OPC), microfine Portland cement (MC), microfine sulphoaluminate cement (MSAC), and self-developed effective microfine cement-based grout (EMCG) were selected, and the penetration grouting diffusion and reinforcement test has been performed. The variation rules of diffusion distance and volume under different suspension and grouting pressures were studied, as well as the effects of grouting material, pressure and sand gradation on the reinforcement. The ANOVA method was adopted to determine the dominant factor for grouting effectiveness, and the macroscopic failure modes of reinforcement specimens were obtained. The microscopic reinforcement model of rock-slurry interface and mineral characteristic were analyzed through SEM method, and the core reasons of reinforcement differences caused by different grouts were revealed. The results show that the grouting material and particle percent in slurry were the dominant factors for the groutability of fine sandy stratum, the increase of groutability was not evident with the increase of grouting pressure. The groutability of EMCG slurry was the best, followed by MC and MSAC, and the groutability of OPC slurry was the worst. The strength improvement of reinforcement specimen was better when the sand gradation was finer when suspensions penetrated fully. The 7 d and 28 d strengths of EMCG reinforcement specimen are higher than those of MSAC, MC and OPC, the 7 d of strength of EMCG reinforcement specimen is greater than 70% value of its 28 d strength. The grout is the dominant factor for reinforcement effectiveness, and EMCG is the best while OPC is the worst. After grouting, the dense C-S-H gels produced in EMCG rock-slurry interface can enhance its bonding strength effectively. Finally, improvement suggestions for practical penetration grouting design have been put forward based on three aspects, which are grouts selection, grouting dynamic control and drilling holes layout. |
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| Keywords: | porous media of sandy soil grouting simulation test penetration diffusion grouts reinforcement effectiveness rock - slurry reinforcement mechanism |
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