改性水玻璃加固细砂室内试验研究  

Laboratory Test on Fine Sand Reinforcement with Modified Sodium Silicate

作　　者：艾振喜 徐厚庆 亢佳伟 邓国华[2,3] AI Zhenxi;XU Houqing;KANG Jiawei;DENG Guohua(The Third Engineering Division of Of CCCC First Highway Engineering Co.,Ltd.,Beijing 100102,China;Institute of Geotechnical Engineering,Xi′an University of Technology,Xi′an,Shaanxi 710048,China;Xi′an Loess Underground Project Technology Consulting Co.,Ltd.,Xi′an,Shaanxi 710000,China)

机构地区：[1]中交一公局第三工程有限公司,北京100102 [2]西安理工大学岩土工程研究所,陕西西安710048 [3]西安黄土地下工程技术咨询有限公司,陕西西安710000

出　　处：《水利与建筑工程学报》2023年第5期33-40,共8页Journal of Water Resources and Architectural Engineering

基　　金：国家自然科学基金(52178355);陕西省自然科学基础研究资助项目(2022JM-216)。

摘　　要：为了探讨磷酸改性水玻璃对工程中细砂层加固的可行性和有效性,在合理确定改性水玻璃配合比的基础上,利用无侧限压力仪和直剪仪对加固砂样的应力应变关系及抗剪强度开展研究,分析改性水玻璃溶液对细砂层的加固效果和机理。试验结果表明:磷酸改性的水玻璃溶液对细砂具有明显加固作用,最优体积配合比为水∶磷酸∶水玻璃=13∶1∶3.3。每1 m^(3)改性水玻璃可固结素砂最大约4 m^(3)。固砂体的轴向抗压强度随时间增长呈现先增大后减小的趋势,无侧限抗压强度处于140 kPa~213 kPa范围,凝结时间为42 h时,抗压强度达到最大。较原状细砂,加固初期黏聚力可增加6 kPa~28 kPa,内摩擦角有所降低;随着凝结时间的增加,黏聚力逐渐减小而内摩擦角有所恢复。This study aims to evaluate the feasibility and effectiveness of using phosphoric acid to modify water glass reinforcement in engineering.Initial experiments determined the optimum mixing ratio of the modified solution,which was then used to test reinforced sand samples using unconfined pressure gauges and direct shear gauges.In addition,the reinforcement effect and mechanism of the modified water glass solution on fine sand layers were investigated.The results show that treatment with phosphoric acid modified aqueous glass solution can significantly improve the strength of fine sand soil.The optimum volume ratio for practical engineering use was found to be 13∶1∶3.3 for water,phosphoric acid and water glass,respectively.In addition,the solution demonstrated the ability to solidify up to 4 cubic meters of plain sand per cubic meter through simulated permeability experiments.When the unconfined compressive strength is in the range of 140 kPa~213 kPa and the setting time is 42 hours,the compressive strength reaches its maximum.The compressive strength of the sand consolidation bodies initially increases and then decreases over time.The use of reinforcement can increase the initial cohesion by 6 kPa~28 kPa compared to undisturbed fine sand while reducing the internal friction angle to a suitable level.

关 键 词：改性水玻璃 磷酸 松散砂层 溶液配合比 抗剪强度 应力-应变曲线 

分 类 号：TU43[建筑科学—岩土工程]