보강재 절단에 의한 보강토옹벽의 파괴에 관한 원심모형실험

유남재,김영길,Yoo, Nam Jae,Kim, Young Gil 대한토목학회 1992 대한토목학회논문집 Vol.12 No.2

보강재 절단에 의한 보강토옹벽의 파괴시 그의 지내력과 파괴 메카니즘을 조사하기 위하여 원심모형실험을 수행하였다. 보강재의 재질, 길이 및 배열을 변화시키면서 실험을 실시하여 그들이 보강토 옹벽의 지내력에 미치는 영향에 관하여 연구하였다. 실험결과를 분석하고 현재 사용되고 있는 여러 설계방법과 비교 검토함으로써 그들의 사용 타당성을 검증하였다. 그 결과로 적정의 설계방법을 제안하였다. Centrifuge model tests were performed to find the capacity and the failure mechanism of reinforced earth retaining wall subjected to the failure due to breakage of reinforcements. Parametric model tests were carried out to figure out effects of factors on the capacity of wall by changing materials of reinforcing strip, strip length, strip arrangement. Tests were analyzed and were compared with the various design methods currently in use to verify feasibility of them. As a result of it, a proper design method was recommended.

Development of Boundary Pressure Gauge

유남재,Yoo, Nam Jae Korean Society of Civil Engeneers 1990 대한토목학회논문집 Vol.10 No.1

암반(岩盤)에 작용하는 응력(應力)을 측정(測定)하는데 사용되는 FLATJACK의 원리(原理)를 이용하여, 흙을 둘러싼 강성경계면(剛性境界面)에 작용하는 연직압력(鉛直壓力)을 측정(測定)할 수 있는 압력계(壓力計)를 개발이용(開發利用)하였다. 본(本) 논문(論文)에서는 새로이 제작(製作)된 토압계(土壓計)의 메카니즘, 압력반응(壓力反應)에 대한 보정계수를 얻는 과정 및 모형실험(模型實驗)에 사용한 결과(結果)에 대하여 서술하였다. 이 계기(計器)를 보강토(補强土)옹벽의 원심모형실험(遠心模型實驗)에 장치하여 모형저면(模型底面)의 강성지반(强性地盤)에 작용(作用)하는 연직압력(鉛直壓力)을 측정하였다. 측정결과치(測定結果値)와 사다리꼴 연직응력분포(鉛直應力分布)의 이론치(理論値)를 비교함으로써 이론(理論)의 타당성(妥當性)을 검증(檢證)하였다. Based on the mechanism of flat jack used to measure stresses in rocks, a prerssure gauge was developed to measure vertical stresses acting on the rigid boundary in a soil mass. This paper describes the mechanism of the newly built pressure gauge, the process of calibrating the response of this gauge, and its use to centrifugal model tests. By installing this gauge in centrifugal model experiments of reinforced earth retaining walls, vertical stress distribution at the rigid boundary of model wall was obtained and compared with theoretical prediction of trapezoidal vertical stress distribution.

방파제 축조공사의 Centrifuge 모델링과 수치해석

유남재,김동건,윤대희,Yoo, Nam-Jae,Kim, Dong-Gun,Yoon, Dae-Hee 강원대학교 산업기술연구소 2011 産業技術硏究 Vol.31 No.2

Centrifuge modeling and numerical analysis on works of breakwater construction were performed to investigate the behavior of caisson type of breakwater and foundation treated with the method of DCM (Deep Cement Mixing) under the condition of wave action in field. In centrifuge modeling, construction sequence of breakwater caisson such as preparation of ground, treatment of DCM, installation of rubble mound, placement of breakwater caisson and lateral loading on the breakwater due to wave action were reconstructed. Lateral movement of model breakwater and ground reaction in the vertical direction were monitored during test. Stress concentration ratio between the untreated ground and the treated ground with DCM was evaluated from measurement of vertical stresses on each ground. Numerical analysis with the software of PLAXIS was carried to compare with Results of centrifuge model test. It was found that stability of model breakwater was maintained during stage of construction and the compared results about stress concentration ratio were in relatively good agreements.

유기질층을 포함한 고소성 실트질 연약지반의 침하 예측

유남재,김겸,유창선,Yoo, Nam-Jae,Kim, Kyum,Yoo, Chang-Sun 강원대학교 산업기술연구소 2011 産業技術硏究 Vol.31 No.2

In this thesis, from the results of settlement measurement performed at the site where embankment earthwork was carried out on the ground consisting of highly plastic and silty soft soils interlayered with organic deposits, various methods of predicting the embankment settlement such as Hoshino's method, Asaoka's method, hyperbolic method, ${\sqrt{s}}$ method and Monden's method were used to investigate their applicability and the inverse method of finding the soil parameter related to consolidation was used to predict the consolidation behavior in the future. It was confirmed that reliable prediction of consolidation behavior under various conditions could be done to estimate soil parameter related to consolidation such as the consolidation index and consolidation coefficient by the inverse method of comparing the measured settlement with the predicted value by the settlement prediction methods.

토사지반에 설치된 역 T형 옹벽의 저판형상이 활동거동에 미치는 영향

유남재,이명욱,김영길,이종호,Yoo, Nam-Jae,Lee, Myung-Woog,Kim, Young-Gil,Lee, Jong-Ho 강원대학교 산업기술연구소 1999 産業技術硏究 Vol.19 No.-

This thesis is to investigate the sliding behavior of cantilever retaining wall by using the commercially available program of FLAC to simulate its behavior numerically. Cantilever retaining walls with flat base, sloped base and base with shear key, uniform surcharges being applied on the surface of backfill, were investigated to figure out appropriate location of shear key beneath the base of wall and, thus, its applicability to field condition was assessed by comparing the analyzed results to each other. On the other hand, previously performed centrifuge model test results (Eum, 1996) were analyzed numerically with FLAC to compare test results with respect to characteristics of load-settlement of surcharges and load-lateral movement of wall. Based on the failure mechanism observed during centrifuge tests, limit equilibrium method of finding the ultimate load inducing the sliding failure of wall was used to compare with values of the ultimate load obtained from conventional method of limit equilibrium method. Therefore, appropriate location of shear key was determined to mobilize the maximum resistance against sliding failure of wall.

2006년 횡성지역 산사태 발생특성

유남재,최준식,Yoo, Nam-Jae,Choi, Joon-Sik 한국토지주택공사 토지주택연구원 2011 LHI journal of land, housing, and urban affairs Vol.2 No.2

본 논문은 강원도 횡성지역에서 집중호우와 태풍 에위니아, 빌리스의 선행강우에 의해 2006년 7월 16일에 발생한 산사태 피해 발생 원인과 특성에 대하여 분석한 결과이다. 산사태 발생의 직접적인 원인은 7월 12일~13일의 선행강우로 지반의 포화도가 증가된 상태에서 7월 15일~16일의 집중호우로 인해 피해가 발생한 것으로 확인되었다. 자연 사면의 산사태 유형은 얕은 심도의 풍화잔류토층과 기반암의 경계면에서 활동이 진행되는 전이형 사면활동으로 확인되었다. 횡성지역에서 발생한 100개소에 대한 자료의 종합적인 분석 결과, 산사태 발생의 사면길이는 100m이하(87%), 사면 폭은 30m이하(74%), 평균사면경사는 $24^{\circ}$로 나타났다. This paper presents the landslide characteristics occurred in Hoengseong, Gangwondo and around July 16 in 2006, caused by heavy rainfall and antecedent precipitation by two typhoons of Ewiniar and Bilis. The main causes of landslides were antecedent precipitation between July 12 to 13, resulting in weakening grounds by increasing the degree of saturation previously, and the additional heavy rainfall between July 15 to 16. Most of landslides at natural slopes were transitional failures occurred along the boundary between residual weathered soil in shallow depth and hard mother rock. From the results of conclusive analyses for 100 sites in Hoengseong region where landslides occurred, the slope length of landslide and slope width were less than 100m with 87% of frequency and 30m with 74% of frequency, respectively. The average value of slope angles was $24^{\circ}$.

부산지역 준설매립지반의 압밀거동 특성 분석

유남재(Yoo, Nam-Jae),김동건(Kim, Dong-Gun)황희석(Hwang, Hee-Seok) 강원대학교 산업기술연구소 2012 産業技術硏究 Vol.32 No.1

For soils with high void ratios, the inverse method of utilizing results obtained from centrifuge model test was used to find the constitutive relation of effective stress - void ratio - permeability whereas conventional oedometer test and constant rate of strain consolidation(CRS) test about settlement of interface and pore pressure and distribution with time were compared with numerically estimated values to confirm such a constitutive relation as obtained from the inverse method. As results of numerical method, the volumetric ratio and reclamation velocity were obtained for the reclamation condition.

비점착성 사면에 인접한 대상기초의 지지력

유남재(Nam Jae Yoo),김영길(Young Gil Kim),전연종(Yeon Jong Jeon) 한국지반공학회 1997 지반 : 한국지반공학회지 Vol.13 No.4

준설매립토지반의 압밀침하량 예측

유남재(Yoo Nam Jae),박병수(Park Byung Soo),정길수(Jeong Gil Soo) 강원대학교 산업기술연구소 2001 産業技術硏究 Vol.21 No.1

For soils with high void ratios, the inverse method of utilizing results obtained from centrifuge model test was used to find the constitutive relation of effective stress - void ratio - permeability whereas conventional oedometer test and constant rate of strain consolidation test were also used to fine its relation at ranges of relatively low void ratio. Results of column test about settlement of interface and pore pressure and distribution with time were compared with numerically estimated values to confirm such a constitutive relation as obtained from the inverse method. Consolidational settlement in dredged and reclaimed ground, where the consolidation was in progress, was predicted by using the numerical technique implemented with the finite strain consolidation theory.

유한 변형률 압밀이론에 의한 연약점토의 자중압밀 침하산정

유남재(Nam Jae Yoo),이명욱(Myung Wog Lee),이종호(Jong Ho Lee) 한국지반공학회 1995 지반 : 한국지반공학회지 Vol.11 No.3