Research On Geotechnical Engineering And Physical Mechanics Characteristics Of Coral Reef

Coral reef is a kind of peculiar geological body,which mainly distributes along the coasts of Guangdong,Guangxi and Sansha coral reefs in China,It is a symbol of territorial sovereignty of our country and an important base for developing marine resources and building air-sea transport relay stations in the South China Sea.The research on the geotechnical properties of coral in China began in the mid-1970s.The research on the geotechnical properties of coral in foreign countries started earlier,mainly on the engineering properties of coral sand.At present,more work is needed on the study of reef limestone.Based on the X reef in the South China Sea and aiming at the reef limestone and coral sand in the coral rock and soil,this paper systematically carries out the experimental study on the engineering geology and physical and mechanical properties of the reef limestone and coral sand.According to the experimental means,combined with the analysis,the research on the characteristics of the coral rock and soil provides the basis for the construction of the South China Sea island reef,and also provides the in-depth study on the engineering geology and mechanical properties of the coral rock and soil.Provide reference materials.The main research contents and conclusions are as follows:?1?Key parameters of foundation bearing capacity?SPT blow count and compression modulus were obtained based on in-situ tests,and the corresponding relationship among the three parameters is obtained.?2?In the strata within the exploration depth of 300 meters,the whole rock analysis?XRD?tests at different depths were carried out to study the mineral composition and content of coral rocks and soils at different depths,and the rocks were named and classified according to the relative percentage content of minerals.The results show that coralline rocks and soils are mainly composed of aragonite?CaCO₃?,calcite?CaCO₃?and dolomite,some of which contain quartz,but their contents vary greatly at different depths.?3?The pore size and void fraction of reef limestone and the acoustic propagation characteristics of reef limestone were studied by mercury intrusion test and longitudinal and shear wave test on coral rock and soil samples with shallow holes and different depths.Based on the rheological test of reef limestone,the rule of rheological failure process of reef limestone is studied.Physical properties of the above-mentioned rocks and soils as corals.?4?Large direct shear tests of undisturbed coral sands under different densities and moisture contents were carried out to obtain mechanical parameters;uniaxial compressive strength of reef limestone under dry and saturated conditions was studied to obtain density,peak strength and elastic modulus parameters of reef limestone under two conditions;triaxial compression tests of reef limestone were completed,molar stress circle of reef limestone was established,and C and?were calculated.Based on the above research,the physical and mechanical properties of coral rock and soil are obtained.