• 한국지반환경공학회 논문집
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• 제6권2호
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• pp.51-60
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• 2005

최근 우리나라는 석회산업의 부산물인 폐석회의 처리문제로 많은 분쟁이 발생하고 있다. 폐석회는 높은 함수비를 갖고 있어 이를 처리하기 위해서는 적절한 탈수과정이 선행되어야 한다. 본 연구는 연직배수공법을 활용하여 폐석회의 높은 함수비를 저하시키고 지반의 안정화를 촉진시키기 위한 효율적인 방안에 대하여 연구하였다. 즉, 폐석회 슬러지로 구성된 지반내에 기성연직 배수재를 설치하였을때, 압밀도와 간극수압의 소산, 침하량 변화, 지지력 증가를 평가하였다. 실험 결과를 고찰해 보면, PBD가 원형드레인 보다 압밀계수가 2배정도 크게 나타났다. 전반적으로 침하량과 간극수압의 소산, 통수량을 비교하면 두 방법이 서로 유사한 경향을 보이고 있으나, PBD가 원형드레인보다 초기 간극수가 더 효과적으로 배수되는 것을 알 수 있었다. 실내배수실험 후 SEM 촬영에 의한 배수재의 필터 층을 살펴보면, PBD에 비해 원형드레인의 필터가 막힘현상이 심한 것을 알 수 있었다. 폐석회지반의 지반개량효과와 간극수의 배수는 PBD가 우수하며, 원형드레인은 타설간격이 길고 PBD와 같은 섬유배열이 균질한 필터로 교환하여 사용할 때 효율성이 증대할 것이라 예상된다.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.279-282
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• 2007

When ground disturbance takes place due to vertical drain construction through mandrel penetration, that affects excess pore water pressure dissipation time because of soft clay coefficient of permeability decreasing. Eventually, consolidation time is influenced. In this research, we measure process of excess pore water pressure dissipation before and after each other different shape's mandrel penetration through model test, and calculates range of smear zone, coefficient of permeability and horizontal coefficient of consolidation after model test. Using of test result, we grasp a degree of drainage ability drop resulting from vertical drain construction.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.542-545
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• 2007

The vertical drain method generate the disturbed zone, because the drainage should be penetrated into the in-situ ground. The characteristics of the smear zone generated cause the problems that the coefficient of permeability decreases and the consolidation time anticipated in the design is not properly shortened. In this study, in order to understand such influence, the laboratory test were carried out so as to reasonably determine the coefficient of consolidation in silt. For that procedure, mandrel of a diversity were penetrated into the soil tube with silt, and then the variation of pore water pressure was measured with the pore pressure meter, Then, the range of smear effect on silt was estimated with monitoring data through the laboratory test, and also analyzed with inputting the coefficient of consolidation into the theoretical equation.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.623-630
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• 2000

In this study, it was to investigate the possibility to use the converts slag, by product in producing steel as a substitute material with sand that is used fur a civil construction materials, in developing techniques to use converts slag to improve soft clay ground. To do this, it was investigated the physical and mechanical properties of the converts slag as a civil construction material. For this, cylindrical cell consolidation with a single vertical drains and large scale soil box test were performed. Through large scale soil box test, the applicability of the converts slag to the present vertical drain techniques which is dependent on sand and plastic drains was studied. As a result of that, it was found that the shape of inserted drains was maintained after completing a consolidation process of a soft clay with slag drains. In addition, we could find that the slag drains showed the similar results with sand drains in soft clay by analyzing the effect of acceleration of consolidation.

• 한국농공학회논문집
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• 제47권5호
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• pp.63-71
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• 2005

In-situ soil remediation mechanism through the vertical drains (VDs) is analyzed with numerical model as the error and complementary error function. Results from in-situ test and analysis indicate that the contaminant concentration ratio as initial one ( C/$C_0$) increases as the radius ratio ( r/R) increases from the injection well, and also increases as the depth ratio ( z/ H) increases from the top of contaminated area. The elapse time needed to attain $50\%$ and $90\%$ clean up level ($ t_{50},\;t_{90}$) increases as the radius ratio ( r/R) and the depth ratio ( z/ H) increase. As above results, the procedure of soil flushing in contaminated area using vertical drains makes progress from the top of injection well to the bottom of extraction well.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 토목섬유 특별세미나
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• pp.9-16
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• 2000

Applicability of the cross shaped drain in a soft clay ground is examined using the laboratory discharge capacity test, column consolidation test and 3-D numerical flow analysis. The equivalent diameter of the tested drains is back-calculated from the laboratory experiment and compared with those calculated from the formula suggested in the literature. The effective range of the cross shaped drain about the discharge capacity and coefficient of permeability is analyzed. The results of numerical analysis show that the cross shaped drain which has a cross-sectional area twice of the band shaped drain can reduce the consolidation time by 30% from that for the band shaped drain in a soft clay ground that K is over 1${\times}$10$\^$-7/cm/sec

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.1400-1407
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• 2005

There are a number of approaches to in situ remediation that are used at contaminated sites for removing contaminants from the contaminated zone without excavating the soil. These include soil flushing, dual phase extraction, and soil vapor extraction. Of these techniques, soil flushing is the focus of the investigation in this paper. The concept of using prefabricated vertical drains(PVDs) for remediation of contaminated sites with fine-grained soils is examined. The PVD system is used to shorten the drainage path or the groundwater flow and promote subsurface liquid movement expediting the soil flushing process. The use of PVDs in the current state of practice has been limited to soil improvement. The use of PVDs under vacuum conditions is investigated using sample soil consisting of silty sand.

• 한국환경복원기술학회지
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• 제10권5호
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• pp.76-86
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• 2007

For the purpose of ground improvement by means of soil flushing systems. Incorporated technique with prefabricated vertical drains have been used for dewatering from fine-grained soils. The laboratory model tests were performed by using the flushing tracer solutions for silty soils and recorded the tracer concentration changes with the elapsed time and flow rates. A mathematical model for prediction of contaminant transport using the PVD technology has been developed. The clean-up times for the predictions on both soil condition indicate more of a sensitivity to the dispersivity parameter than to the extracted flow rate and vertical velocity parameters. Based on the results of the analyses, numerical analysis indicate that the most important factor to the in-situ soil remediation in prefabricated vertical drain system is the effective diameter of contaminated soil.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.597-604
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• 2002

This paper reviews depositional environments of marine deposits along the Nakdong river and then analytical solution of self-weight consolidation considering artesian pressure is made to find consolidated state. It's known that this area is in the under-consolidated state by the artesian pressure(u$\_$a/=0.3kg/$\textrm{cm}^2$) and the distribution of the artesian pressure is not linear but parabola. In predicting consolidation settlement for soft grounds improved by vertical drain, it is emphasized that the self-consolidation by sudden dissipation of artesian pressure should be considered.

• 한국지반신소재학회논문집
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• 제10권1호
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• pp.29-36
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• 2011

오염지반 복원을 목적으로 사용한 연직배수시스템의 적용성 평가를 위하여 영향 인자에 대한 지반공학적 특성을 기초로한 파일럿 규모의 실내 오염복원 실험시 오염물질의 복원 효율을 분석하였다. 또한, 도출된 결과를 바탕으로 유한요소 및 유한차분방법에 의한 수치해석을 수행하였으며, 해석시 적용된 물성값에 대한 매개변수를 평가하였다. 오염복원 모형실험과 수치해석에서 최소한계농도비를 기준으로 하여 오염복원율 해석 결과, 지반이 조밀한 경우 최소한계 농도비 도달시간이 더 길어지며, 지속시간에 따른 농도분포를 살펴보았을 때, 농도는 주입배수재를 중심으로 그 주변에서 더 빠르게 제거되고, 반면에 추출배수재 주변에서는 농도가 더 높게 나타남을 알 수 있었다.