• Journal of the Korean Geotechnical Society
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• v.36 no.12
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• pp.7-16
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• 2020

This study presents an acoustic technique to estimate the hydraulic conductivity of soils. Acoustic attenuation and propagation velocity spectra were measured for dry and saturated sandy specimens to confirm that the relationship between Biot's characteristic frequency and its associated hydraulic conductivity exists only for saturated soils. From the experiments presented in this paper, both attenuation-based and propagation-velocity-based techniques resulted in almost identical characteristic frequencies for saturated soils. The propagation velocity based measurements, however, show a a a slightly clearer trend compared to the attenuation based measurements. The results also show that the acoustically estimated hydraulic conductivities of soils agree well with constant head laboratory test results, demonstrating that this acoustic technique can be a useful nondestructive tool to estimate the hydraulic conductivity of sandy or silty soils.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.2
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• pp.54-61
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• 1997

This study has conducted to analyze the crelationship among soil properties and to investigate how they affect soil physical characteristics and plant growth. The experiment of woody plant growth was conducted as follows : Type I was the original soil. Type II, the soil particles smaller than 20${\mu}{\textrm}{m}$ was removed from the original soil. Type III, the soil particles is smaller than 75${\mu}{\textrm}{m}$ was removed from original soil. Wisteria floribunda A.P.DC and Celtis sinensisi Pers. were used for plant growth measurement. 1. Soil type II. the closest to Fuller's curved line, showed high dry bulk density and low in soil pores and saturated hydraulic conductivities. This created poor soil aeration and limited space for the root to growth. When the root did not have sufficient space to grow, there was a lot of physical stress, which hindered the root growth. 2. Soil typeIII was high saturated hydraulic conductivity and a lot of soil pores larger than 10 ${\mu}{\textrm}{m}$. As a result, there were more available spaces for root to spread. It was considered that there was less physical stress for root growth. Therefore, soil typeIII showed significantly greater root growth. 3. Because soil type III has less small particles and saturated hydraulic conductivity was high, and water infiltrates rapidly into the underground when there was rainfall or irrigation. The soil typeIII becomes much stronger soil mechanically due to the less small particles. Therefore, soil typeIII was a suitable material for applying on planting sites where soil compaction is expected.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.435-441
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• 2008

More time is required for consolidating soft clay when its hydraulic conductivity around the vertical drains is reduced by soil disturbance. One of the methods to be proposed to solve such problem is the electro-osmotic flow application. This study presents the experimental results of model tests using a modified oedometer and a large-scale cylinder with a sand drain. Results show that the development of negative excessive pore water pressure due to the DC electrical field in saturated clay can be transformed to additional loads causing more consolidation settlement.