Variation in Micro-Pores during Dynamic Consolidation and Compression of Soft Marine Soil

Abstract

In this study, to explore the microstructure deformation mechanism of marine soft marine soil under cyclic loading, we analyzed the dynamic properties of soft marine soil under cyclic loading via dynamic consolidation compression testing. Then, using Image-Pro Plus (IPP) 6.0 image analysis software, and according to the dynamic consolidation compression test results and the images from a scanning electron microscope (SEM), we determined the weakening effect of soft soils under different consolidation confining pressures, different cyclic stress ratios, and different over-consolidation ratios. After dynamic consolidation and compression, the pore structure of undisturbed soft marine soil tends to compact, the degree of soil particle fragmentation intensifies, small pores increase, large pores decrease, the pores become more regular, and the distribution of pores is directional. Subsequently, for undisturbed soft marine soil, the higher the consolidated confining pressure, cyclic dynamic stress ratio, and over-consolidation ratio, the greater the damage to the pore structure, and the more obvious the structural weakening effect exhibited under cyclic loading.

Microstructural Variation of Clay during Land Subsidence and the Correlation between Macroscopic and Microscopic Parameters

“…Test methods such as X-ray diffraction, double oedometer tests, and scanning electron microscopy (SEM) were combined to analyze the evolution of the microstructure of loess during collapse, in order to explain the mechanism of loess collapse [ 19 , 20 , 21 ]. Methods such as mercury intrusion porosimetry (MIP) and SEM were used to study the deformation and microstructural mechanism of soft soil under cyclic loading, and the variation of the microstructural parameters in the deformation process of soft soil was discussed [ 22 , 23 ]. Conventional tests such as unconsolidated–undrained and direct shear tests, as well as the SEM method, were used to analyze the correlation between the shear characteristics of red clay and the change laws of the microstructure from qualitative and quantitative perspectives [ 24 , 25 ].…”

Effect of Nutrient Solution Composition on Bio-Cemented Sand

“…Then, the sample is scanned, and a picture with a magnification of 1000 on the screen is taken. IPP software is used for binary processing of the SEM image [30][31][32].…”

An Experimental Study on the Microstructure Evolution of Soil under Lateral Consolidation Compression

“…The preparation of the SEM sample is the basis of capturing SEM images. To ensure that the scanning image can accurately reflect the true morphology of the sample, certain requirements should be met in the preparation of SEM samples: the disturbance and damage of the samples should be minimized, the shrinkage deformation of the sample should be minimized in the drying process, uniformity should be ensured as much as possible when spraying the conductive medium and the thickness of the samples should be appropriate [36,37].…”

“…The purpose of image processing was to extract information from the images and output data of pore characteristics for statistical analysis. The processing steps were divided into three: the calibration of the pixel space, binarization processing and automatic software analysis [37]. (1) Firstly, a calibration of the pixel space was required.…”