\r雷华阳^{1, 2}，屠慈科¹，王 磊¹，李宸元\r¹\r
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AuthorsHTML:\r雷华阳^{1, 2}，屠慈科¹，王 磊¹，李宸元\r¹\r
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AuthorsListE:\rLei Huayang^{1, 2}，Tu Cike¹，Wang Lei¹，Li Chenyuan\r¹\r
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AuthorsHTMLE:\rLei Huayang^{1, 2}，Tu Cike¹，Wang Lei¹，Li Chenyuan\r¹\r
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Unit:\r1. 天津大学建筑工程学院，天津 300354；
2. 滨海土木工程结构与安全教育部重点实验室(天津大学)，天津 300354\r
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Unit_EngLish:\r1. School of Civil Engineering，Tianjin University，Tianjin 300354，China；
2. Key Laboratory of Coast Civil Structure Safety of Ministry of Education(Tianjin University)，Tianjin 300354，China\r
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Abstract_Chinese:\r\r吹填土中所含的丰富的可溶盐对其物理力学特性有着极大的影响．通过配置不同硫酸钠掺量的含盐吹填土试样，研究了可溶盐含量对吹填土强度及变形特性的影响，并利用\rSEM\r电镜扫描试验分析了吹填土微观结构特征的变化规律，从微观角度分析了其宏观力学特性的变化机理．研究结果表明：由于钠离子作用，土颗粒吸附水膜的厚度不断增大，粒间吸引团聚作用减弱，吹填土试样内部孔隙增大，结构更加疏松，宏观上表现为强度不断减小\r(\r最大降低幅度达\r44.1\r%\r)\r，压缩性相应增大；随着含盐量的不断增加，由于硫酸钠的结晶及相关离子反应导致硫酸钙的生成，吹填土试样内部胶结作用有所增强，强度会出现约\r29.6\r%\r的增长，压缩性相应减小．而当含水量增大时，钠离子对土颗粒团聚作用的影响以及硫酸钠的结晶作用被弱化，硫酸钙对吹填土的增强作用对其力学特性有更显著的影响．试样内部开始有明显的粒间胶结物生成，粒间孔隙减小，颗粒团聚，形成了较明显的团粒结构，土骨架效应显著，宏观上呈现出抗剪强度不断增大\r(\r最大增幅约\r335.5\r%\r)\r、压缩性不断减小的变化特点．吹填土试样在可溶盐环境下的应力\r-\r应变关系呈现应变硬化特征．\r\r
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Abstract_English:\r\rThe abundant soluble salts contained in dredged fill greatly influence its physical and mechanical properties\r．\rIn this study\r，\rwe investigated the effect of the soluble salt content on the strength and deformation characteristics of dredged fill by configuring salt-filled dredged fill samples with different sodium sulfate contents\r．\rWe used scanning electron microscopy to analyze changes in the microstructure of the dredged fill and the change mecha-nism of the macroscopic mechanical properties from the microscopic point of view\r．\rThe results show that due to the effect of sodium ions\r，\rthe thickness of the water film absorbed onto soil particles continuously increases\r，\rwhich weakens the agglomeration effect of the particles such that the pores in the dredged fill sample become larger and the structure becomes looser\r．\rMacroscopically\r，\rthe strength continuously reduces\r(\rthe maximum reduction was 44.1\r%\r)\r，\rand the compressibility increases accordingly\r．\rAs the salt content continues to increase\r，\rthe crystallization of sodium sulfate and the formation of calcium sulfate caused by the reaction of related ions enhance the internal cementation of the dredged fill sample\r．\rAs a result\r，\rits strength increases by about 29.6\r%\r and the compressibility decreases accordingly\r．\rHowever\r，\rwhen the water content increases\r，\rthe effects of the sodium ions on the agglomeration of soil particles and the crystallization of sodium sulfate are weakened\r，\rand the enhancement effect of the formation of calcium sulfate has a more significant influence on the mechanical properties of the dredged fill. In our tests\r，\rwe observed the formation of an obvious intergranular cement in the samples\r，\rwith smaller intergranular pores\r，\rand the agglomeration of particles formed a relatively obvious agglomerate structure\r．\rThe soil skeleton effect was significant\r．\rMacroscopically\r，\rthe shear strength increased\r(\rthe \rmaximum increase is about 335.5\r%\r)\rand the compressibility continuously reduced\r．\rWe can conclude that the stress-strain relationship of dredged fill in a soluble salt environment exhibits strain hardening characteristics\r．\r\r
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Keyword_Chinese:吹填超软土；含盐量；力学特性；微观结构\r

Keywords_English:ultra-soft dredger fill；salt content；mechanical properties；microstructure\r


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