Research on Coarse-Grained Soil Collapsibility in Gobi Region

Nie, Zhi Hong; Li, Kun; Xia, Jianling

doi:10.4028/www.scientific.net/amr.446-449.1450

Cited by 3 publications

(2 citation statements)

References 3 publications

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“…The matrix of the clay-gravel layer is mostly clay, and there is a certain bonding force between the clay and the gravel. In the natural state, the stratum can maintain a certain strength and has a high stability, but when it is disturbed or the environmental conditions change, the bonding ability is significantly reduced., and the engineering stability will also be greatly affected (Nie et al, 2012;Qian et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Shear Strength Characteristics of Clay-Gravel Layer and Its Slope Failure Law and Mechanism

et al. 2022

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The Anqing Formation clay-gravel layer is widely distributed in the Anqing area of the upper reaches of the Wanjiang River. It is a typical soil-rock mixture composed of gravel and clay. The poor engineering properties of the clay-gravel layer are the main factors for the failure of the slope. On the basis of regional geological survey, the clay-gravel threshold, clay mineral composition and cementation characteristics of clay-gravel layer were studied. The in-situ horizontal push-shear tests under different gravel content, water environment and overlying load were designed and carried out, and its shear failure mode and strength were analyzed. The study found that the shear zone was in the shape of a broken line and was controlled by the particle size and distribution of the gravel. The shear strength of the clay-gravel layer is relatively high in the natural state due to the structure of the gravel and the friction and cementation force between the clay and the gravel. Water had the greatest influence on the shear strength of the clay-gravel layer, and the overlying load affected its shear strength within a certain range. The indoor rainfall erosion model test of the clay-gravel slope was carried out, and the failure and instability modes and mechanisms of the slope with different gravel contents were studied. When the gravel content was 30%, the failure of the slope surface was the development of gullies. The erosion damage process was similar to the soil slope. When the gravel content was 50%, affected by the distribution of gravel, the slope failure was manifested as the development of erosion pits, followed by local slumps, and finally the overall sliding in layers. When the gravel content was 70%, the clay particles on the slope were quickly washed away by the water flow, and the gravel skeleton of the slope formed a temporary relatively stable structure. After being disturbed, the gravel layer collapsed as a whole.

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Section: Introductionmentioning

confidence: 99%

Shear Strength Characteristics of Clay-Gravel Layer and Its Slope Failure Law and Mechanism

et al. 2022

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“…Tomioka et al [19] observed bentonite particles of compacted samples before and after water saturation by a newly developed X-ray microscopic CT having a high spatial resolution. Nie et al [20] determined the microscopic structure to analyze the collapsibility of coarse-grained soil and explored the mechanism of collapsibility generation by carrying out SEM on coarse-grained soil in the Gobi region. Wang et al [21] performed the tensile tests and SEM test to analyze changes of the loess microstructure in the tensile test.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation and Microscopic Stress Mechanism for the Microscopic Pore Deformation during Soil Compression

Tao

Peng

Xiao

et al. 2019

Advances in Civil Engineering

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Pore structure is closely related with strength, constitutive relation, consolidation characteristics, and permeability properties of soil. Consequently, improving the understanding of the relationship between microscopic structure and macroscopic physical and mechanical properties has extremely important scientific significance. A large number of studies have shown that pores of soil have fractal features, and hence, the carpet model can be used to approximately simulate the fractal structure of clay. In the present study, ANSYS software was selected to establish a microscopic model of clay to study the distribution of microscopic stress and microscopic deformation characteristics of pores under different consolidation pressures. Besides, the variation law of microscopic pore size was quantitatively determined by using IPP (Image-Pro Plus) software. Combined with the fractal theory, the changes of microscopic pore of numerical simulation and that of physical experiment during compression of clay are studied. All the results indicated that the microscopic stress distribution of clay is not uniform on the compaction process. The larger the pore size is, the bigger the compression stress on both sides and the greater the bending deformation of upper part of the pore is, which leads to the deformation of larger pores which is bigger than that of smaller pores. Based on the results, issues about the microscopic mechanism of the difference in vertical and horizontal permeability under compression of clay, the relationship between the changes of pore shape and microscopic stress, the preliminary principle of “preferential crush of larger particles” for granular soil, skeleton stress across the region where stiffness is relative larger, and the self-protection of particles and pores are also discussed. The results of this study are of great importance in understanding of soil compression and related physical and mechanical properties from the microscopic view.

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Experimental study on the correlation between the partial and total salt content in saline gravel using ion chromatography

Wang

Liu

et al. 2021

Transportation Geotechnics

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Research on Coarse-Grained Soil Collapsibility in Gobi Region

Cited by 3 publications

References 3 publications

Shear Strength Characteristics of Clay-Gravel Layer and Its Slope Failure Law and Mechanism

Shear Strength Characteristics of Clay-Gravel Layer and Its Slope Failure Law and Mechanism

Numerical Simulation and Microscopic Stress Mechanism for the Microscopic Pore Deformation during Soil Compression

Experimental study on the correlation between the partial and total salt content in saline gravel using ion chromatography

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