لخّصلي

Coarse particles make up the basic skeleton and shape of soils and endow them with a positive resistance to loading and deformation.As a result, the hydraulic reclamation mouth is piled high with abundant calcareous coarse-grained soil (Wang et al. 2020, 2021), which forms some "reef hills" and tremendous areas of "ponds" (Figure (2.29-a). The "reef hills" pile at the hydraulic reclamation mouth is on the whole calcareous coarse-grained soil with a maximum particle size of 300 mm. The "ponds" are within the low-lying area of the hydraulic reclamation website and contain massive quantities of calcareous fine-grained soil with a particle size less than 0.075 mm and a plasticity index of 6.5 (termed calcareous silt).Calcareous sand is a marine biogenic, porous, loose granular geomaterial (Wang et al. 2011, 2017), whose mechanical behaviour is affected by the FC. Calcareous sand serves as the handiest filling material for land reclamation in the extension projects of several island-reefs inside the South China Sea (Shen et al. 2020; Wu et al. 2020).The enormously compressible, saturated calcareous silt and silty quality sand basis is liable to differential settlement below loading, which impacts the safety and durability of homes (Wang et al. 2020).

Coarse particles make up the basic skeleton and shape of soils and endow them with a positive resistance to loading and deformation. In opposite, fine particles fill void areas in the soil skeleton and keep the stability of the soil skeleton device. Fine particles are critical in cementing soil particles and keeping soil structure. An alternate in fines content (FC) will reason an alternate within the internal microfabric characteristics of the soil, which affects the mechanical behaviour. Calcareous sand is a marine biogenic, porous, loose granular geomaterial (Wang et al. 2011, 2017), whose mechanical behaviour is affected by the FC. Calcareous sand serves as the handiest filling material for land reclamation in the extension projects of several island-reefs inside the South China Sea (Shen et al. 2020; Wu et al. 2020). During hydraulic reclamation of the land area on island-reefs in the South China Sea, to lessen the time spent on adjusting the hydraulic reclamation pipeline, hydraulic reclamation is raised to the layout elevation once for numerous running regions. As a result, the hydraulic reclamation mouth is piled high with abundant calcareous coarse-grained soil (Wang et al. 2020, 2021), which forms some “reef hills” and tremendous areas of “ponds” (Figure (2.29-a). The “reef hills” pile at the hydraulic reclamation mouth is on the whole calcareous coarse-grained soil with a maximum particle size of 300 mm. The “ponds” are within the low-lying area of the hydraulic reclamation website and contain massive quantities of calcareous fine-grained soil with a particle size less than 0.075 mm and a plasticity index of 6.5 (termed calcareous silt). Calcareous silt is notably compressible and could crack beneath dry–wet cycles (Figure (2.29-b), results in site settlement. After levelling the hydraulic reclamation site, the higher segment of the authentic low-lying place is backfilled with coarse aggregates, which results in a calcareous coarse-grained soil layer, of which the lower section is a fine-grained silt layer with a non-uniform thickness. According to an analysis of borehole samples, the upper section of the silt layer is calcareous silt, while the lower segment is a combination of calcareous silt and calcareous silty quality sand (Figure (2.29-c). The enormously compressible, saturated calcareous silt and silty quality sand basis is liable to differential settlement below loading, which impacts the safety and durability of homes (Wang et al. 2020). Therefore, the effect of FC at the mechanical behaviours of calcareous sand ought to be decided to assess the engineering safety of island reefs.