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Leaching Characteristics on Clay Ground induced by Artesian Pressure

피압에 의한 점토 지반의 용탈 특성

Daeho Yun1
,
Yuntae Kim2*
윤 대호1
,
김 윤태2*
1Graduated student, Department of Ocean engineering, Pukyong National University
2 Professor, Department of Ocean Engineering, Pukyong National University
*교신저자. *Corresponding Author. 
30 December 2016. pp. 97-104
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Abstract

This paper performed consolidation tests on soft ground with and without artesian pressure conditions to find out characteristics of leaching effects using two types of one-dimensional column equipment(height : 1,100mm, outer diameter : 250mm). Artesian pressure of 5.5kPa was applied to the bottom of soft ground inside column equipment. Distribution of salinity and shear strength with soil depth were measured after the consolidation test. From the results, it was found that distribution of undrained shear strength and salt concentrations were similar at the top of clay ground irrespective of artesian pressure condition. However, at the bottom of clay ground, the values of undrained shear strength and salt concentration under artesian pressure were lower than those without artesian pressure. This result indicates that structure of soft soil with artesian pressure was weakened by salt leaching. Electronic resistance results showed that void ratio under artesian pressure condition was more reduced than that without artesian pressure condition.

Keywords
Artesian pressure
Undrained shear strength
Soft ground
leaching effect
Electrical resistivity

본 연구에서는 피압의 작용에 따른 점토 지반의 용탈 특성을 조사하기 위해 두 종류의 원통형 일차원 대형 컬럼 장치(높이 : 1,100mm, 직경 250mm)를 제작하여 점토 지반의 압밀 거동 실험을 수행하였다. 피압의 크기는 5.5kPa로 하부지반에서부터 작용하도록 하였으며, 압밀 실험 종료 후 점토층의 깊이에 따른 염분의 농도와 비배수 전단강도를 측정하였다. 실험 결과 비배수 전단강도 및 염분 분포는 점토층 하부에서 뚜렷한 차이를 보였으며, 상부로 갈수록 유사한 경향을 보였다. 이는 피압이 작용할 경우 점토층 내에 용탈현상이 발생하여 지반이 구조적으로 취약해져 나타난 결과로 판단된다. 또한 전기전도도 측정을 통해 시간에 따른 간극비 변화를 살펴본 결과, 피압이 작용하는 지반에서 간극율 변화가 더 크게 나타났다.

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Information
  • Publisher :Korean Geosythetics Society
  • Publisher(Ko) :한국지반신소재학회
  • Journal Title :Journal of the Korean Geosynthetics Society
  • Journal Title(Ko) :한국지반신소재학회 논문집
  • Volume : 15
  • No :4
  • Pages :97-104
  • Received Date : 2016-11-07
  • Revised Date : 2016-12-25
  • Accepted Date : 2016-12-25
  • DOI :https://doi.org/10.12814/jkgss.2016.15.4.097
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