저배합 흙시멘트의 역학적 특성에 관한 시험적 연구

공길용 ( Kong Kil Yong ),김현태 ( Kim Hyun Tae ),노종구 ( Ro Jong Koo ),홍병만 ( Hong Byung Man ) 한국농공학회 2001 韓國農工學會誌 : 전원과 자원 Vol.43 No.6

In order to expand agricultural lands in the western and southern coasts of Korean Peninsula, ,coarse soils excavated from hillsides have been used as fill materials for reclamation. In order to tackle with the problems and to confirm availability, research on soil improvement involve mixing cement to the fine wet soils. Required undrained shear strength (c_u) for fill material was analyzed to be 0.34 ~1.2kgf/cm². It has been known that when cement is added to high water content marine clay, its unconfined compression strength increased to 2kgf/cm². Consolidation results show that pre-consolidation pressure increased to 1.8kgf/cm² and 3.4kgf/cm² with the addition of 3% and 5% of cement respectively. This result shows that low-height embankments could be constructed without significant compression. Since the effectiveness of improvement may be different site by site, the mix design for each site is necessary in order to optimize it. The process is first to determine aimed shear strength and then optimum mix ratio of cement after carrying out a series of tests.

시멘트계 고화재를 이용한 농로의 보조기층 안정처리공법 연구

공길용 ( Kong Kil Yong ),장병욱 ( Chang Pyoung Wuck ) 한국농공학회 2001 韓國農工學會誌 : 전원과 자원 Vol.43 No.3

A few study has been performed on the durability of subbase treated with geo-cement for the farm road although many papers for the road treated with soil-cement were published. The objectives of the study are to develop the stabilizing method of subbase using additives of cement groups and 2nd additives such as gypsum and MgO, etc. A series of test was performed to investigate possible mixing ratios with geo-cement A, B, C, D and 2nd additives on the various soft soils from the rice paddy. Based on test results, durability index was greatly affected by geo-cement D which was mainly composed with gypsum Compressive strength of clayey soil such as Soil I was less than threshold strength(30kgf/㎠) but the strength was increased as addition of gypsum and MgO. It is recommended that geo-cement for soil stabilization has to be carefully Chosen because strength Characteristics of subbase are varied not only with soils but also with addition of geo-cement and 2nd additives. The developed method in this study can be used to subbase treatment of low-cost agricultural roads.

고화재를 이용한 친환경 농어주도로 시험시공 사례

공길용 ( Kong Kil-yong ),김현태 ( Kim Hyun-tae ),김석열 ( Kim Seog-yeol ),정인영 ( Chung In-young ) 한국농공학회 2004 한국농공학회 학술대회초록집 Vol.2004 No.-

If soils and geo-cement are treated by mixing and its strength and durability are improve. It can be used as pavement material in order to construct a rural road where has not to much traffic futhermore development of eco-friendly construction method pertaining to rural roads can be possible. This paper subject to trial construction of a rural road by using geo-cement and it was confirmed suitable possibility through laboratory test(strength, durability etc.) or on-site research(core test).

석회계 고화재를 이용한 간척지내 경작로 포장방안

공길용 ( Kong Kil-yong ),김현태 ( Kim Hyun-tae ),이규섭 ( Lee Kyu-seop ),김영호 ( Kim Young-ho ) 한국농공학회 2005 한국농공학회 학술대회초록집 Vol.2005 No.-

In order to construct the farm road in Shi-Hwa project, coarse soils excavated from hillsides have been used as road materials for reclamation. Suitable borrow pits available in land are now limited and also they bring about environmental problems when soils are excavated at the borrow pits and transported to the site. When using fine and wet materials as fill, however, many engineering problems can be encountered. Usually, the materials have high water contents, low strength, and high compressibility. In order to use them, we need research that can improve the inherent properties of those materials. In order to tackle with the problems, researches on soil improvement involve mixing lime geo-cement to the fine wet soils. A lab model test is necessary to verify effectiveness and comparison of those techniques. A field test is also required to show applicability and to find problems that may exist in the design and construction stages.

토목섬유를 사용한 무처리 연약지반과 성토사이의 수평배수층

이형규,공길용,김현태,Lee, Hyoung-Kyu,Kong, Kil-Yong,Kim, Hyun-Tae 한국농공학회 2002 韓國農工學會誌 : 전원과 자원 Vol.44 No.4

This paper presents a study on the discharge capacity of geotextiles as a horizontal drain layer placed between the layers of earth fill and natural soft ground. Required discharge capacity of geotextiles as drain layers estimated by consolidation analysis is proportional to the consolidation coefficient of the ground soils and the width of the earth fills. The field discharge capacity of the geotextiles are measured by the hydraulic transmissivity test. And the results show wide variation according to the material characteristics of geotextiles, water content of the soils, vertical pressure, and etc. For the short horizontal drain length, geotextile filter mat can be used for the horizontal drain layer. And f3r the long drain($25{\sim}55m$), it is used for the drain together with Bord Drain.

고화토보조기층을 활용한 경작도로포장 시험시공 사례

김현태 ( Kim Hyun-tae ),공길용 ( Kong Kil-yong ),김석열 ( Kim Seog-yeol ),홍병만 ( Hong Byung-man ) 한국농공학회 2004 한국농공학회 학술대회초록집 Vol.2004 No.-

흙과 시멘트를 혼합처리하면 강도가 크게 증가한다. 이를 이용하여 흙-시멘트를 보조기층 또는 기층 등의 대체재료로 사용할 수 있다. 특히, 교통량이 적은 경작도로 포장공사에는 표층까지도 고화처리토로 포장하고자하는 시도가 이루어지고 있다. 그러나 고화처리표층은 표면이 마모되는 단점이 있어 고화처리기층 위에 아스콘표층을 포장하는 공법이 유효할 것이다. 본 연구에서는 3가지 종류의 흙에 대하여 시멘트혼합처리 조건에 대한 일축압축시험과 CBR시험을 실시하여 보조기층 또는 기층으로 대체사용 가능성을 확인하였으며, 그 위에 아스콘 표층만을 시공하는 조건으로 경작도로 포장 시험시공을 통하여 그 가능성을 확인하였다. 본 연구에서 경작도로를 이루고 있는 대표적인 3가지 흙에 대하여 고화처리조건에 대한 일축압축과 동결융해반복 및 CBR시험을 실시하여 보조기층 또는 기층의 대체재료로 사용 가능성을 확인한 결과 보조기층 및 기층으로 충분히 사용할 수 있는 결과를 얻었다. 그리고 흙-시멘트를 보조기층(30cm)과 기층 (20cm)으로 사용하고 그 위에 아스콘표층 7cm로 경작로 포장 시험시공을 실시한 결과 3년이 경과한 현재 상태가 양호하며, 이 공법을 현장 실무에 적용하기 위하여 고화처리토를 활용한 포장설계와 품질관리에 대한 기준 및 실무요령의 정립이 필요하다는 결론을 얻었다. The strength is largely increased when soil and cement are mixed compared to soil alone. It can be utilized as substitute material for base or subbase on road pavement. It even can be used as surface material for pavement on low traffic road such as farm road. The study has confirmed that this soil-cement mixture can be used as substitute material for base or subbase on road pavement through Uniaxial Compression Test and CBR Test on three different soils and it has also been verified through trial construction on farm road pavement.

토목섬유를 사용한 무처리 연약지반과 성토사이의 수평배수층

김현태 ( Kim Hyun Tae ),이형규 ( Lee Hyoung Kyu ),공길용 ( Kong Kil Yong ) 한국농공학회 2002 韓國農工學會誌 : 전원과 자원 Vol.44 No.4

This paper presents a study on the discharge capacity of geotextiles as a horizontal drain layer placed between the layers of earth fill and natural soft ground. Required discharge capacity of geotextiles as drain layers estimated by consolidation analysis is proportional to the consolidation coefficient of the ground soils and the width of the earth fills. The field discharge capacity of the geotextiles are measured by the hydraulic transmissivity test. And the results show wide variation according to the material characteristics of geotextiles, water content of the soils, vertical pressure, and etc. For the short horizontal drain length, geotextile filter mat can be used for the horizontal drain layer. And f3r the long drain(25~55m), it is used for the drain together with Bord Drain.

벤토나이트를 혼합한 준설해사의 차수재 활용성

김서룡 ( Kim Seo-ryong ),이득원 ( Lee Duc-won ),공길용 ( Kong Kil-yong ),유전용 ( Woo Jeon-yong ),김현태 ( Kim Hyun-tae ) 한국농공학회 2003 한국농공학회 학술대회초록집 Vol.2003 No.-

There is a case to use dredged-sea sand as a filling material because of difficulty of obtaining required filling material for tideland reclamation project from the land. At this time, side slope erosion is occurred because the precipitation falling to the top of bank acts as infiltration water when it pass through inside of the semi-permeable filling section. This study has confirmed the declining effect of permeability by conducting permeability test to the condition of mixing of bentonite to the dredged sea-sand. And also this study has confirmed that the above processed-soil could be used as a water-proof layer to protect infiltration of water through the infiltration flow analysis.