Research on Dynamic Deformation of Nano-SiO2-Improved Cement-Soil Under Cyclic Loading and Its Microstructure Analysis
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摘要: 运用GDS真/动三轴仪和PQ001型低磁场核磁共振分析仪探究纳米SiO2改良水泥土的动力特性及其内部孔隙变化。动力特性试验结果表明:水泥土的动应力-动应变曲线随纳米SiO2掺量增加先上移后下降,动变形模量-动应变曲线、同级荷载滞回曲线圈面积、阻尼比-动应变曲线随着纳米SiO2掺量增加先下降后上移,在纳米SiO2掺量为2.5%时,水泥土抵抗动荷载能力最强;孔结构分析得出纳米SiO2改良水泥土的内部孔隙结构得到改善,强度提高。推荐纳米SiO2最优掺量为2.5%。Abstract: The dynamic characteristics of nano-SiO2-improved cement-soil and the change of internal micro-pore structure of nano-SiO2-improved cement-soil were studied with the dynamic triaxial test apparatus of GDS and the nuclear magnetic resonance test apparatus PQ001.The dynamic triaxial test results showed that theσd-εd curve of cement-soil first rising and then decline with the increase of the nano-SiO2 content. The curve of the dynamic deformation modulus and dynamic strain, the area surrounding by the hysteresis curve under the same level load, and the curve for damping ratios and dynamic strain of cement-soil first decline and then rising with the increase of the nano-SiO2 content. When the nano-SiO2 content was 2.5%, the dynamic resistance of cement-soil was maximun. Micro structure analysis of cement-soil showed that the pore structure and strength of nano-SiO2-improved cement-soil were increased. The optimal nano-SiO2 content was 2.5%.
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Key words:
- cement-soil /
- nano-SiO2 /
- dynamic characteristic test /
- micro structure analysis
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