Bearing Capacity of Shallow Foundation on Geogrid-Reinforced Clay

신방웅,다스브라자,신은철,정기택,Shin, Bang Woong,Das, Braja M.,Shin, Eun Chul,Chung, Kee Taek Korean Society of Civil Engeneers 1994 대한토목학회논문집 Vol.14 No.6

Laboratory model test results for the ultimate bearing capacity and allowable bearing capacity at various settlement levels conducted on a strip foundation supported by geogrid-reinforced clay soil have been presented. For mobilization of the maximum possible load-carrying capacity, the optimum width and depth of the reinforcement layers, and the location of the first layer of reinforcement with respect to the bottom of the foundation have been determined.

Suction Effect during Pullout of Anchors in Clay

신방웅,신은철,이준대,다스브라자,Shin, Bang Woong,Shin, Eun Chul,Lee, Jun Dae,Das, Braja M. Korean Society of Civil Engeneers 1994 대한토목학회논문집 Vol.14 No.6

Laboratory model test results for uplift capacity of a circular plate anchors embedded in saturated clayey soils have been presented. Clayey soils used in this study are kaolinite and montmorillonite. Suction effects on the ultimate uplift capacity of plate anchors with respect to various embedment depths of anchor have been considered.

Bearing Capacity of Vertically Reinforced Sand Subgrades

신방웅,신은철,이봉직,퓨리 비제이,다스 브라자,Shin, Bang Woong,Shin, Eun Chul,Lee, Bong Jik,Puri, Vijay K.,Das, Braja M. Korean Society of Civil Engeneers 1994 대한토목학회논문집 Vol.14 No.4

This paper presents a new method of soil improvement by using semi-flexible vertical reinforcing elements which shows promise for future work. Load tests were conducted on two model footings in a sand box using unreinforced sand and also by reinforcing the sand with vertical reinforcing elements. The ultimate bearing capacity for the unreinforced and reinforced sand has been compared. The effect of length, spacing, lateral extent of the reinforcement, and the initial relative density of sand in increasing the ultimate bearing capacity have been evaluated. The effect of roughness of the reinforcing elements has also been investigated. Based on the results of these model footing tests, it appears that significant improvement in the ultimate bearing capacity of loose and medium sands can be achieved by reinforcing with vertical elements.

청주지구 다짐화강토의 공학적 특성

신방웅,이광동,오세욱 ( Bang Woong Shin,Kwang Dong Lee,Se Wook Oh ) 충북대학교 건설기술연구소 1997 建設技術論文集 Vol.16 No.2

Abstract_Roman The weathered granite soil has been used with geotechnical materials at foundation in situ. As this soil is non-homogeneous and anisotropic as well as very various, it has been differed geotechnical properties. Then this study on weathered

An Experimental Study on the Unsteady Seepage

신방웅,Shin, Bang Woong Korean Society of Civil Engeneers 1985 대한토목학회논문집 Vol.5 No.1

비정상(非定常) 침투문제(浸透問題)에서 가장 중요하고 어려운 점은 자유수면(自由水面)의 위치(位置)와 그 변화(變化)를 어떻게 해석(解析)하느냐이다. 그러므로 본(本) 연구(硏究)는 특히 수위상승(水位上昇)에 따른 제체내(堤體內) 침투(浸透)와의 상관계수를 찾았으며(즉, 수위상승에 대해 $V_R=\frac{dH}{dt}$, 침투속도에 대해 $V_S=Ki=k\frac{H-d_1}{d}$), 또한 기(旣) 발표(發表)된 식(式)들을 분석(分析)하여 실험자료(實驗資料)와의 비교 정리(整理) 분석(分析)하였다. The most important and difficult part in the problem of unsteady seepage is, how to analyze a position and variation of free water level. Therefore, this paper found the relation between the rising water level and infiltration in the embankment by analyzing established equations and extrapolated the empirical equations from experimental data (For the seepage velocity; $V_S=Ki=k\frac{H-d_1}{d}$, For the rising velocity level; $V_R=\frac{dH}{dt}$) With the aid of these data, the necessary equations were compared with the experimental analyses.

수평흐름에 의한 제방모형내의 비정상침투에 관한 실험적 연구

신방웅,이봉직,Shin, Bang Woong,Lee, Bong Jik 대한토목학회 1994 대한토목학회논문집 Vol.14 No.5

The stability of the embankment is depended upon the location of seepage line. As the seepage flow occurs in the embankment, the slope of the embankment loses its stability. Of particular interest is the stability following a rapid change of embankment level. The variation of seepage line in the embankment model according to flow velocity was investigated. In addition to this non-steady state flow in embankment by a fluctuation of water level is discussed. The experimental model was construction with slopes of 1 : 2.5 and flow velocity is turned from 60 cm/sec~90 cm/sec. Analysis of the experimental results, the seepage line is influenced by flow velocity and coefficient of permeability.

모래로 축조(築造)한 제체(堤體)의 사면안정(斜面安定) 해석(解析)

신방웅,최기봉,Shin, Bang Woong,Choi, Gi Bong 대한토목학회 1985 대한토목학회논문집 Vol.5 No.4

본(本) 연구(硏究)는 제체(堤體)에 있어서, 수위(水位)가 급상승(急上昇)함에 따라 제체내부(堤體內部)의 공극수압(空隙水壓)이 변화(變化)하는 제체경사면(堤體傾斜面)의 파괴현상(破壞現象)을 연구(硏究)한 것이다. 그리고 이미 발표(發表)된 근사이론식(近似理論式)을 토대로 국부(局部) 파괴현상(破壞現象)을 실험(實驗)을 통(通)하여 고찰(考察)했다. 본(本) 실험(實驗)에서 연구(硏究)된 내용(內容)은 다음과 같다. 1) 침윤선(浸潤線)에 따른 유출점(流出點)의 위치 결정(決定) 2) 유출점(流出點) 부근(部近)에서 발생(發生)되는 국부(局部) 파괴현상(破壞現象)에 대한 고찰(考察) 3) 침투수압(浸透水壓)이 제체(堤體)에 미치는 영향(影響) The author has studied the collapse of a slope with seepage occuring in sand model with a trapezodial cross section. The primary objective of this study was to examine the failure phenomenon of embankment with respect to change in void pressure at embankment slope. The contents of this experiments are as follows; 1) Determination of exit point by seepage line. 2) Evaluation of partial failure at exit point. 3) The effects of seepage force at embankment.

이형제체의 침투에 관한 연구

신방웅,이봉직,Shin, Bang Woong,Lee, Bong Jik 대한토목학회 1991 대한토목학회논문집 Vol.11 No.1

The phreatic surface in earth embankment of zone types are investigated in this thesis. Also the shape of phreatic surface are analyzed according to rising velocity and slope angle. In order to verify the validity of experimental results, the results are compared with theoretical result. From this comparison, the shape of phreatic surface in multi-layer is predicted by heat transfer equation.

Embankment Stability under Rapid Drawdown

신방웅,박재관,Shin, Bang Woong,Park, Jae Gwan Korean Society of Civil Engeneers 1985 대한토목학회논문집 Vol.5 No.4

수위변화(水位變化)에 따른 상이(相異)한 자유수면(自由水面)으로 인(因)하여 제체내부(堤體內部)에 응력상태(應力狀態)가 달라지므로 제체(堤體)의 안정해석(安定解析)이 필요(必要)하다. 수위(水位)가 급강하(急降下)할 경우 상류측(上流側) 사면(斜面)에서의 자유수면방향(自由水面方向)이 기초(基礎)쪽으로 바뀌어질 때, 상류측(上流側) Fill의 안전율(安全率)을 찾아 보았다. 여기서 하강(下降)하는 자유수면(自由水面)과 파괴형태(破壞形態)를 찾았으며, 또 안전율(安全率)을 구(求)하였고. 이로 강하속도(降下速度) 및 동수경사(動水傾斜)를 비교(比較)하였다. 실험(實驗)에 의한 결과(結果)는 다음과 같다. 1. 자유수면(自由水面)의 강하(降下)로 인(因)하여 상류측(上流側) Fill에 침투류(浸透流)에 의한 골동파괴(滑動破壞)가 일어나고, 파괴고(破壞高)는 각(各) 각(各)의 모형(模型)에 따라, 5~10, 9~15, 13~21(cm)이다. 2. 침투류(浸透流)에 의한 간극수압(間隙水壓)의 영향(影響)을 고려(考慮)하여 안전율(安全率)을 구하였으며, 이때 강하속도(降下速度)와 안전율(安全率)과의 관계(關係)에서 제체(堤體)의 안전상(安全上) 강하속도(降下速度)는 0.21~0.28(cm/sec)이어야 하고, 동수경사(動水傾斜)와 안전율(安全率)과의 비교(比較)에서 동수경사(動水傾斜)는 각(各) 모형(模型)에서 0.36~0.43 값보다 적어야 함을 실험상(實驗上) 알았다. Stability analysis of the embankment as to water level varation is the most important problem in the safety of the slope because the stress of embankment inside varies as to drawdown of seepage line. Especially when the water level is rapidly drawdown, because the flow direction of the free surface changes the toe of embankment, the factor of safety comes to small, therefore the embankment is dangered. For the purpose of studing these phenomena, the experimental models are built with sand in the laboratory. In the experimental consideration, the falling seepage line and the shape of failure are measured. This paper intends to study the failure slip surface, the relationship between the factor of safety and drawdown velocity, and hydraulic gradient. The results of the experimental study are summarized as follows; 1. Owing to the drawdown of free surface, sliding failure occurred in the upstream fill, the height of failure is 5~10, 9~15, and 13~21(cm) in each model. 2. In consideration of the distribution of pore water pressure Table-5 shows each factor of safety. In the relationship between the drawdown velocity and the factor of factor it's velocity should be limited to 0.21~0.28 (cm/sec), according to each models. In the relationship between the factor of safety and the hydraulic gradient within the upstream slope, it's gradient must be below 0.36~0.43.

다져진 화강토에 대한 복합항복면 구성모델의 적용

신방웅,오세욱,정태욱 ( Bang Woong Shin,Se Wook Oh,Tae Wook Jeong ) 충북대학교 건설기술연구소 1997 建設技術論文集 Vol.16 No.2

Abstract_Roman Since Lade and Duncan(1972-1977) proposed several original elasto-plasfic constitutive model based on testing of the granular soil, it is again proposed by Lade that single and double work-hardening model which proved to give accurate stre