The hydraulic reclamation coral clay is a new type of clay,formed during the sorting process of coral island reef reclamation.The foundation of the hydraulic reclamation coral reef consists of coral sand,silt,and clay...The hydraulic reclamation coral clay is a new type of clay,formed during the sorting process of coral island reef reclamation.The foundation of the hydraulic reclamation coral reef consists of coral sand,silt,and clay.The part of the particles with particle size less than 0.075 mm contain more than 50%forms clay.As a new type of clay,the geotechnical properties were rarely reported in previous studies.In this paper,the physical and mechanical properties,microstructure and mineral composition were comprehensively researched by a series of laboratory tests.The results show that coral clay is a low liquid limit clay with high pore ratio and high saturation.From the aspect of mineral compositions,the coral clay studied consists of calcite and aragonite,while the chemical composition of it is calcium carbonate.The void ratio has a significant effect on the compressive properties of coral clay.With the increase of the void ratio,the compression coefficient a_(1-2) and compression index C_(c) gradually increase,and the compression modulus Es gradually decreases.The undrained stress−strain curve of coral clay shows a strain-softening behavior,and the peak strength and residual strength are positively linear correlated with confining pressure.展开更多
The durability of silty clay embankments is partially controlled by the moisture migration, which depends on soil hydraulic properties. This paper presents an experimental study of hydraulic properties of compacted bi...The durability of silty clay embankments is partially controlled by the moisture migration, which depends on soil hydraulic properties. This paper presents an experimental study of hydraulic properties of compacted binary silty clay. Specimens with different mixing ratios and dry densities were prepared. Scanning electron microscopy and mercury intrusion porosimetry were used to characterise the microstructure of silty clay. Thereafter, falling-head permeability tests and water retention tests were conducted to study the permeability and water retention property, respectively. The results demonstrate that clay particles are dispersed and show preferred arrangements after compaction when the clay content is 100%. As the clay content decreases, the arrangement of clay particles is gradually disturbed because of the existence of silt particles, causing the formation of large pores around silt particles. When the dry density increases, the pores around silt particles significantly decrease. Moreover, the permeability of silty clay decreases but the water retention capacity increases with increasing clay content and dry density. This is because the silty clay with larger clay content and dry density has fewer large pores, which greatly restrains the flow of water. Both the permeability and water retention property of silty clay can be predicted from pore size distribution parameters.展开更多
基金Projects(51878103,41831282,51778092)supported by the National Natural Science Foundation of China。
文摘The hydraulic reclamation coral clay is a new type of clay,formed during the sorting process of coral island reef reclamation.The foundation of the hydraulic reclamation coral reef consists of coral sand,silt,and clay.The part of the particles with particle size less than 0.075 mm contain more than 50%forms clay.As a new type of clay,the geotechnical properties were rarely reported in previous studies.In this paper,the physical and mechanical properties,microstructure and mineral composition were comprehensively researched by a series of laboratory tests.The results show that coral clay is a low liquid limit clay with high pore ratio and high saturation.From the aspect of mineral compositions,the coral clay studied consists of calcite and aragonite,while the chemical composition of it is calcium carbonate.The void ratio has a significant effect on the compressive properties of coral clay.With the increase of the void ratio,the compression coefficient a_(1-2) and compression index C_(c) gradually increase,and the compression modulus Es gradually decreases.The undrained stress−strain curve of coral clay shows a strain-softening behavior,and the peak strength and residual strength are positively linear correlated with confining pressure.
基金Projects(51908069, 51908073, 51838001, 51878070) supported by the National Natural Science Foundation of ChinaProject(2019SK2171) supported by the Key Research and Development Program of Hunan Province, China+2 种基金Project(kfj190605) supported by the Open Fund of Engineering Laboratory of Spatial Information Technology of Highway Geological Disaster Early Warning in Hunan Province (Changsha University of Science & Technology),ChinaProject(2019IC04) supported by the Double First-Class Scientific Research International Cooperation Expansion Project of Changsha University of Science & Technology, ChinaProject(kq1905043) supported by the Training Program for Excellent Young Innovators of Changsha, China。
文摘The durability of silty clay embankments is partially controlled by the moisture migration, which depends on soil hydraulic properties. This paper presents an experimental study of hydraulic properties of compacted binary silty clay. Specimens with different mixing ratios and dry densities were prepared. Scanning electron microscopy and mercury intrusion porosimetry were used to characterise the microstructure of silty clay. Thereafter, falling-head permeability tests and water retention tests were conducted to study the permeability and water retention property, respectively. The results demonstrate that clay particles are dispersed and show preferred arrangements after compaction when the clay content is 100%. As the clay content decreases, the arrangement of clay particles is gradually disturbed because of the existence of silt particles, causing the formation of large pores around silt particles. When the dry density increases, the pores around silt particles significantly decrease. Moreover, the permeability of silty clay decreases but the water retention capacity increases with increasing clay content and dry density. This is because the silty clay with larger clay content and dry density has fewer large pores, which greatly restrains the flow of water. Both the permeability and water retention property of silty clay can be predicted from pore size distribution parameters.
