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
To reveal the bearing capacity of the X-section pile group in coral sand, a series of model load tests are conducted.The testing results are presented as load-settlement curves, pile-soil stress ratios, distributions ...To reveal the bearing capacity of the X-section pile group in coral sand, a series of model load tests are conducted.The testing results are presented as load-settlement curves, pile-soil stress ratios, distributions of side friction and axial force, and load-sharing ratio between side and tip resistances. The reliability and accuracy of the numerical simulation model are verified by comparing the results of the model test. Comparative analysis between X-section and circular section piles with the same cross-sectional area indicates that the bearing capacity of the X-section pile group is much larger than that of the circular pile group. The axial force of X-section piles is smaller while the peak skin friction is larger than that of circular piles at the same depth. The skin friction of the core pile is the largest,followed by the side pile and the corner pile is the smallest when the load is relatively small;however, it is converse when the load is larger than 10 k N. Compared with piles in silica sand, the pile in coral sand has a lower bearing capacity, and the sand breakage leads to the steep drop failure of pile foundation. Moreover, pile positions under the raft have less effect on the load-share differences among corner, side and core piles in coral sand. This study provides a reference for the construction of pile foundations in coral sand.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financially supported by the National Key Research and Development Program of China (Grant No. 2016YFE0200100)the National Natural Science Foundation of China (Grant Nos. 51878103 and 41831282)。
文摘To reveal the bearing capacity of the X-section pile group in coral sand, a series of model load tests are conducted.The testing results are presented as load-settlement curves, pile-soil stress ratios, distributions of side friction and axial force, and load-sharing ratio between side and tip resistances. The reliability and accuracy of the numerical simulation model are verified by comparing the results of the model test. Comparative analysis between X-section and circular section piles with the same cross-sectional area indicates that the bearing capacity of the X-section pile group is much larger than that of the circular pile group. The axial force of X-section piles is smaller while the peak skin friction is larger than that of circular piles at the same depth. The skin friction of the core pile is the largest,followed by the side pile and the corner pile is the smallest when the load is relatively small;however, it is converse when the load is larger than 10 k N. Compared with piles in silica sand, the pile in coral sand has a lower bearing capacity, and the sand breakage leads to the steep drop failure of pile foundation. Moreover, pile positions under the raft have less effect on the load-share differences among corner, side and core piles in coral sand. This study provides a reference for the construction of pile foundations in coral sand.
