천연섬유배수재의 시험시공 및 현장 계측

김주형(Ju Hyong Kim),조삼덕(Sam-Deok Cho) 한국토목섬유학회 2006 한국지반신소재학회 학술발표회 Vol.2006 No.4

Although the discharge capacity of the natural fiber drains are very low compared to that of plastic drain board (PDB), it is found that the conventional fiber drains and the new developed straw drain boards have great potential for use as a substitute for conventional plastic drain boards through several model tests. To verify their field application, a pilot test using environmentally friendly drains is also being carried out to prove their effective discharge capacity in the field. The pilot test site was divided into 5 different areas, with various combinations of vertical and horizontal drains installed for evaluation. Conventional natural fiber drains and new developed straw drain board used as vertical drains, while sand and fiber mats were used as horizontal drains. The initial monitoring data obtained at the pilot test site will prove whether environmentally friendly drains are able to be used as substitutes of conventional plastic and sand material.

수평배수재가 포설된 준설매립지반의 압밀해석(II) - 현장설치조건에 의한 개량효율 분석 -

장연수,김수삼,박정용 한국지반공학회 2005 한국지반공학회논문집 Vol.21 No.10

The gravitational consolidation behavior of the dredged ground with horizontal drains is analyzed using a finite difference program developed for self-weight consolidation analysis with horizontal drains. The influence of area and direction of horizontal drains on the consolidation time and settlement is analyzed. Various field conditions such as the non-treated ground below horizontal drain installed ground, the accumulation of drained water at the end of horizontal drains, are also included in the analyses. It was found that a slight decrease of consolidation time is resulted in the twice increase of the sectional area of drains. Installing drains vertically can reduce the consolidation time more significantly than installing drains horizontally. The analyses showed quantitatively that the non-treated ground below the horizontal drain installed ground has much influence on long term consolidation settlement, and the accumulation of hydraulic head at the end of horizontal drains results in the increase of consolidation time and insufficient consolidation.

제내 비탈끝 배수공을 이용한 제방의 침투조절에 관한 연구

공영산,강태욱,이상호 한국수자원학회 2012 한국수자원학회논문집 Vol.45 No.6

하천 제방은 홍수 시 유수를 원활하게 소통시키고 제내지를 보호하기 위해 하천을 따라 축조한 시설이다. 하지만 이러한 제방도 침투로 인해 제내지측 사면에 포화표면이 지속적으로 발생하게 되면, 제방은 파괴될 수 있다. 제체 침투에 의해 발생되는 침윤선은 적절한 배수 체계를 이용하여 강하될 수 있다. 본 연구의 목적은 제내지 비탈 끝에 설치되는 배수공을 통한 침투조절의 효과를 제시하고, 각기 다른 형상을 하고 있는 미국의 공병단과 일본의 국토개발기술연구센터에서 제시한 배수공의 효과를 비교, 검토하는데 있다. 이를 위해 배수공의 포함 여부에 따른 제방 침투에 관한 모형실험을 수행하였다. 축조된 제방 모형의 규격은 둑마루폭 0.5m, 하부폭 2.6m, 사면경사 1 : 2, 제방 높이 0.55m이고, 제외지측 수위는 0.5m이다. 미 공병단의 배수공은 삼각형이고 일본의 국토개발기술연구센터의 배수공은 사각형이며, 각각의 배수공 폭은 0.4m로 설치하였다. 배수공을 포함하지 않은 제방 모형에서는 침투에 의해 제내지측 사면에 포화표면이 발생하였으나, 미 공병단과 일본의 국토개발기술연구센터에서 제시한 배수공을 포함한 제방에서는 모두 포화표면이 발생하지 않았다. 이러한 모형실험의 결과는 SEEP/W를 통한 수치모의 모형의 보정과 검증에 활용되었다. 그리고 배수공의 폭을 5 cm씩 줄여가며 수치모의를 수행해 본 결과, 일본의 국토개발기술연구센터식 배수공이 미국의 공병단식 배수공에 비해 다소 안정한 것으로 분석되었다. 또한, 일본의 국토개발기술연구센터식 배수공은 시공이 쉬운 장점이 있다. 본 연구의 결과는 향후 배수공을 이용한 제방의 침투조절 계획에 활용될 수 있을 것으로 전망된다. The levee is the facility which is constructed along with river for the protection of landside and for passage of water when there is a flood. When the seepage is exposed to the atmosphere on the landside surface of levee, it may eventually lead to levee failure. The seepage water may be removed from the landside surface by a properly designed drainage system. The purpose of the study is to show seepage control effect of a pervious toe drain, and to compare two drainage methods of a pervious toe drain. One is the pervious toe drain suggested by U.S. Army Corps of Engineers (USACE) and the other is that suggested by Japan Institute of Construction Engineering (JICE). The levee model constructed has the following dimension: the base width is 2.6 m; the crest width is 0.4 m; the side slope 1 : 2. The water depth in the riverside is 0.5 m. The shape of the toe drain by USACE is triangular. The shape of the toe drain by JICE is rectangular. They were installed with the base length of 0.4 m. The levee model without the toe drain showed saturation surface on the land side in the experiment but not with the toe drain. The experiment results was applied to a numerical analysis model using SEEP/W to calibrate and verify. The numerical analysis results for 35 cm and 30 cm drain width showed that the drain by JICE is a little bit safer than the drain by USACE. It is also easier to construct the toe drain by JICE. The results in the study would be applied to plan the seepage control for a levee with pervious toe drain.

고관절 전치환술 후 흡입 배액관의 효용성

임수재 ( Soo Jae Yim ),신동훈 ( Dong Hoon Shin ),김민영 ( Min Young Kim ),차주석 ( Joo Seok Cha ),제한웅 ( Han Woong Je ),김응하 ( Eung Ha Kim ),서유성 ( Yoo Sung Seo ),이병일 ( Byung Il Lee ) 대한고관절학회 2006 Hip and Pelvis Vol.18 No.3

목적: 고관절 전치환술 후 흡입 배액관을 사용한 군과 사용하지 않은 군에서 수술 후 임상 결과 및 혈액학적 결과를 분석하여 흡입 배액관의 장단점 및 그 필요성을 알아보고자 하였다. 대상 및 방법: 2001년 6월부터 2004년 6월까지 본원에서 동일 수술자에 의해 고관절 전치환술을 받은 86예를 대상으로 하였으며 수술 후 흡입 배액관을 사용한 48명을 1군, 사용하지 않은 환자 38명을 2군으로 하여 수술 중 및 배액관을 통한 실혈량, 수술 후 실혈량과 수혈량, 수술 전후의 혈색소치, 임상 결과를 분석하였다. 임상적 결과는 고관절 운동범위와 상처부위의 부작용 및 전신적 부작용을 조사하였다. 결과: 수술 전후의 혈색소치에서는 흡입 배액관을 사용하지 않은 군에서 수술 후 혈색소치가 높았으나 통계학적으로 유의한 차이가 있지는 않았다. 양 군의 총 실혈량은 흡입 배액관을 사용하지 않은 군에서 의미 있게 낮았고 수술 후 수혈량도 흡입 배액관을 사용하지 않은 군에서 낮았다(p<0.05). 그 외 수술 후 창상 치유 및 수술 후 6주째의 고관절 운동범위는 최종 추시 상 양 군 사이에 유의한 차이를 보이지 않았다. 결론: 고관절 치환술 후 흡입 배액관을 사용하지 않음으로서 발생하는 고관절 운동 장애나 창상 감염 등은 발견할 수 없었으며 오히려 실혈량을 줄임으로써 수술 후 동종수혈량을 줄일 수 있었다. 따라서 고관절 치환술 후 흡입 배액관을 사용하지 않는 것이 배액관을 사용함으로써 발생할 수 있는 수혈량의 증가, 역류성 감염의 가능성 등의 부작용을 방지할 수 있으며 배액관을 사용하지 않아 비용면에서도 경제적인 이득이 있을 것으로 보인다. Purpose: The goal of this study was to evaluate the efficacy of suction drains following total hip arthroplasties, by comparing the post-operative results between the group with suction drains and the group without suction drains. Materials and Methods: Eighty-six patients, who underwent primary total hip arthroplasties from June 2001 to June 2004, were divided into two groups: group 1 (48 patients), with suction drains; and group 2 (38 patients), without suction drains. We assessed the perioperative hemoglobin and platelet levels, the amount of total blood loss, the amount of post-operative blood transfusions, post-operative ranges of motion (ROMs, at 6 weeks), wound problems, and general conditions. Results: Although the postoperative hemoglobin level was greater in group 2 than in group 1, there was no statistically significant difference. The amount of total blood loss and blood transfusions in group 1 were statistically greater than in group 2 (p<0.05). There were no statistically significant differences in the post-operative ROMs and wound complications between groups 1 and 2. Conclusion: There were no limitations of hip motion and no wound complications in the patients without suction drains after total hip arthroplasties. However, they required fewer post-operative blood transfusions than did the patients with suction drains, due to less post-operative blood loss; and the absence of a suction drain might prevent retrograde tube infections. In addition, patients without suction drains after total hip arthroplasties seemed to recover better did than those with suction drains. Therefore, suction drains might provide no benefit in total hip arthroplasties.

Drain Leakage and Hot Carrier Reliability Characteristics of Asymmetric Source-drain MOSFET

김광수,Byoungseon Choi,백도현,김형욱,최병덕 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.5

The asymmetric source-drain metal-oxide-semiconductor field-effect transistor (MOSFET) was characterized in detail in comparison with the conventional symmetric source-drain MOSFET. The principal difference between asymmetric and symmetric source-drain MOSFETs is the drain-side structure. The asymmetric source-drain MOSFET has a lightly-doped drain for a low electric field. As a result, the gate-induced drain leakage (GIDL) current is reduced, and the hot carrier reliability is improved.

자궁경암 근치수술후 배액 수단으로서 Hemovac drain과 Rubber drain의 배액 효과에 대한 비교적 연구

박상윤(SY Park),서호석(HS Suh),신만우(MW Sin) 대한산부인과학회 1983 Obstetrics & Gynecology Science Vol.26 No.7

Comparative Study on the Effect of Hemovac drain and Penrose drain in Case of Radical Surgery for Cervical Carcinoma In the operation of radical hysterectomy with pelvic lymphnode dissection, the method of drainage of secretion accumulated in operating wound has been a serious problem for gynecologists since the operating technic was discribed by E. Wertheim in l9l2. Traditionally, open drainage had been used with a various complication caused by a large dead space created by surgical dissection and associated contamination. A randomized retrospective and prospective trial of closed suction drainage using Hemovac compared with open drainage using Penrose drain after radical hysterectomy with pelvic lymphnode dissection is performed to evaluate the effect of drainage in l62 cases. The results of this study are as follows: 1. There were no significant differences in clinical characteristics such as clinical sta ges of cervix csncer, patients age, amount of blood transfusion during operation. 2. Average amount of drainage during 5 days after operation were 727.7±l68.4 m1 in Hemovac group, and 233.7±68.4gm in Penrose drain group. The difference between the two groups is statisticaly signiScant (p<0.01). 3. Average duration of injection antibiotics admitistration after operation were l3.6 ± 3.2days in Hemovac group, and 18.7±4.6 days in Penrose drain group. The difference between the two groups is statisticaly significant (p<0.06). 4. Average duration of oral antibiotics administration after operation were 20.4±7.8 days in Hemovac group and 28.7 ±9.8 days in Penrose drain group. The difference between the two groups is statistically significant (p<0.01)

연직배수재 종류에 따른 통수능력 평가

신은철(Eun Chul Shin),김성환(Sung Hwan Kim),조삼덕(Sam Deok Cho),이은수(Eun Soo Lee) 한국토목섬유학회 2006 한국토목섬유학회 학술발표회 Vol.2006 No.12

Vertical drain technology is widely used to accelerate the consolidation of soft clay depoits & dredged soil under preloading. Discharge capacity is one of the factors affecting the behavior of vertical drains. In the field, a vertical drains are confined by clay or dredged soil, which is normally remolded during vertical drain installation. Under field conditions, soil particles may enter the drainage channels, and the consolidation settlement of the improved subsoil may cause folding of the vertical drains. These factors will affect the discharge capacity of the vertical drains. An experiment study were carried out to obtain the discharge capacity of three different types of vertical drains by utilizing the large-scale model tests. The several factors were studied such as confinement condition (confined by soft marine clay or dredged soil) and variations of the discharge capacity with time under clay confinement. The test results indicated that discharge capacity decreases with increasing load, time and hydraulic gradient. With load application, the cross-sectional area of the drainage channel of vertical drains decreases because the filter of vertical drains are pressed into the core. The discharge capacity is also reduced at a high hydraulic gradient due to the loss of flow energy as a result of turbulent flow.

플라스틱 배수재를 이용한 수평배수공법에 관한 연구

황정규,김홍택,김석열,강인규,김승욱 한국지반공학회 1998 지반 : 한국지반공학회지 Vol.14 No.6

In the present study, 2-D consolidation theory of the dredged clay by means of the horizontal drain method is proposed. The horizontal drain method to install the drains such as plastic drain board within the dredged clay is a soil improvement method to accelerate the consolidation by expelling pore water in the vertical direction along the horizontal drains. Based on the finite strain consolidation theory by Gibson et al., the partial differential equation of 2-D consolidation due to the horizontal drain is derived. The consolidation due to the horizontal drain can be illustrated from combined self-weight consolidation effect and consolidation effect by horizontal drains. For the prediction of consolidation settlement and degree of consolidation numerical analysis is suggested on the basis of Dufort-Frankel finite differential algorithm. Also, the analytical procedures proposed in this study are verified by the model tests, and the predictions of the consolidation settlement and degree of consolidation are compared with the results obtained from the tests for the dredged clay gathering at Siwha site in Ansan, Korea. For the predictions, the relationship void ratio vs effective stress and the relationship permeability vs void ratio of the dredged clay are obtained from the odometer tests. Additionally, the parametric study for consolidation settlement by variations of design parameters related with horizontal drain method is carried out. Based on the results of the parametric study, design .charts for the preliminary design are also proposed. 본 연구에서는, 연약한 준설매립점토지반 내부에 플라스틱 배수재를 수평으로 설치하여 압밀침하의 가속화를 유도하는 수평배수공법의 해석절차 체계화에 초점을 두고 이론적 및 실험적 접근을 진행하였다. 이를 위해, 유한변형률 개념을 근거로 한 Gibson등의 1차원 자중압밀이론을 토대로, 자중압밀효과 및 수평배수재 설치에 따른 추가 압밀효과를 복합적으로 고려하는 지배방정식을 제시하였으며, 본 지배방정식 및 수평배수재 설치효과를 고려한 초기조건 및 경계조건 등을 토대로, Dufort-Erankel의 유한차분화 알고리즘을 이용해 시간경과에 따른 침하량 및 압밀도 등의 변화를 예측하기 위한 해석절차를 제시하였다. 또한 제시된 해석절차의 적용 타당성 확인을 위해, 안산 시화지구 준설매립점토 및 플라스틱 수평배수재를 이용한 실내모형실험을 실시하였다. 실내실험을 통해, 안산 시화지구 준설매립점토의 간극비-유효응력 관계 및 투수계수-간극비 관계 등을 정량적으로 정의하기 위한 기초자료를 획득 하였으며. 또한 시간경과에 따른 깊이별 침하량등을 측정하여 본 연구에서 제시된 해석절차에 의한 예측치와 비교.분석하였다. 이외에도 플라스틱 배수재 수평배수공법에 관련된 설계변수가 압밀침하등에 미치는 영향을 제시된 해석절차를 이용해 분석하였으며, 이 결과를 토대로 한 설계도표의 제시도 이루어 졌다.

연직천연섬유배수재를 이용한 연약지반 개량

김주형(Kim Ju-Hyong),조삼덕(Cho Sam-Deok) 한국토목섬유학회 2008 한국지반신소재학회 논문집 Vol.7 No.4

친환경배수재에 대한 현장 적용성을 평가하기 위해 연직배수재와 수평배수재 설치 조합으로 현장시험시공을 수행하였다. 본 시험시공에서는 기존의 천연섬유배수재(FDB)와 새로 개발한 볏짚배수재(SDB) 그리고 플라스틱배수재(PDB)를 연직배수재로 설치하였으며, 화이버매트와 샌드매트를 수평배수재로 사용하였다. 볏짚배수재(SDB) 설치지역을 제외하고는 플라스틱배수재(PDB)와 천연섬유배수재(FDB) 설치 지역에서 측정한 지표침하발생속도와 과잉간극수압 발생/소산 양상은 거의 유사한 것으로 나타났으며, 1차 압밀방치기간동안 측정된 상부 연약층의 콘관입저항력도 설치된 연직배수재 종류와 상관없이 일정하게 증가한 것으로 나타나 천연섬유배수재가 기존의 플라스틱이나 모래재료를 대체할 수 있을 것으로 판단된다. A pilot test using environmentally friendly drains, was carried out to evaluate their applicability potential in the field. The pilot test site was divided into 5 different areas, with several combinations of vertical and horizontal drains installed for evaluation. Conventional natural fiber drains (FDB), new developed straw drain board (SDB) and plastic drain board (PDB) were used as vertical drains, while sand and fiber mats were used as horizontal drains. Surface settlement rates and excess pore pressure generation/dissipation tendency of PDB and FDB are almost identical except those of SDB. Cone tip resistance obtained from cone penetration test measured at the end of 1st consolidation stage for upper soft layer definitely increased irrespective of types of vertical drains. The monitoring and site investigation test data obtained at the pilot test site prove the vertical natural fiber drains can be used as substitutes of conventional plastic and sand material.

Horizontal Drain of Composite PBD and Consolidation Delay Due to Mat Resistance

Mitsuharu Fukuda,Sei Ji Suwa 한국지반공학회 2012 international journal of geo-engineering Vol.4 No.2

Sand of well quality is difficult to be supplied for horizontal drain to accelerate consolidation velocity. On the other hand, pre-fabricated board drain (PBD) is recognized as an alternative major material. PBD is generally installed in gridlike manner. However, its conventional drain design manual is insufficient in order to take various materials into consideration. In this paper, two layers horizontal drain model and its numerical treatment by differentiation for computing is presented to promote the PBD horizontal drain design. A consolidation delay is the important issue for the applicability of PBD horizontal drain. The consolidation delay caused by a mat resistance is analytically presented by Yoshikuni. As the PBD horizontal drain is installed in different manner from the Yoshikuni model, a reasonable and compatible mat resistance factor should be constituted for the gridlike fashion. In this paper, a new treatment will be presented considering the similarity of equation with Yoshikuni`s mat resistance factor. After comparing the consolidation delay induced by the presented model with Yoshikuni model, the proposed design procedure for the PBD horizontal drain is investigated.