Properties of one-dimensional compression for hydrate-bearing soil
The property of one-dimensional compression for hydrate-bearing soil is an important means to ana-lyze the deformation of hydrate-bearing strata.Based on the physical properties of sediments from SH3 boreholes in Shenhu sea area of the South China Sea,fine-grained soil was artificially prepared as hydrate occurrence me-dium,and hydrate-bearing soil samples were formed and one-dimensional compression tests were carried out.The effects of hydrate saturation and ambient temperature on the compression deformation of hydrate-bearing soil were studied.The test results show that as the saturation of hydrates increases and the ambient temperature de-creases,the soil containing hydrates becomes more difficult to compress and its compressibility decreases.The influence of hydrate saturation and ambient temperature on pre-yield compression index and swelling index is not obvious,but the increase of hydrate saturation and decrease of ambient temperature will significantly reduce the pre-yield compression index and increase the preconsolidation pressure.The formation of hydrate fills the pore space and solidifies soil particles,but the decrease of environmental temperature makes the cementation more obvious,and it is difficult for the soil particles and hydrate particles to move and rearrange,so the soil is diffi-cult to be compressed and the overall structure becomes stronger and stronger as the pre-consolidation pressure increases.According to the analysis,the empirical relationship between the preconsolidation pressure and the hydrate saturation is proposed,and the mathematical expression which can effectively describe the one-dimen-sional compression curve is given.
hydrate-bearing soilone-dimensional compressionpreconsolidation pressurecompression indexrebound index
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