압밀(壓密) 특성(特性)에 관(關)한 연구(硏究)(II) -하중(荷重) 증가율(增加率)이 압밀특성(壓密特性)에 미치는 영향(影響)-

강예묵,류능환,Kang, Yea-Mook,Ryu, Neung-Hwan 충남대학교 농업과학연구소 1977 Korean Journal of Agricultural Science Vol.4 No.1

흙의 압밀시험(壓密試驗)에서 하중증가율(荷重增加率)을 변화(變化)시켰을 때 압밀(壓密)의 제계수에 미치는 영향을 고찰하기 위하여 표준압밀시험(標準壓密試驗)에서 적용하는 전하량(戰荷重) 증가율(增加率)을 여러가지로 변경(變更)하여 압밀시험(壓密試驗)을 실시(實施)하여 다음과 같은 결과(結果)를 얻었다. 하중증가율(荷重增加率)이 클수록 침하량(沈荷量)은 크나 팽창량(膨脹量)은 하중증가율(荷重增加率)과 무관(無關)하다. 일침압밀(一沈壓密) 완자점(完子點)까지의 시간은 하중증가율(荷重增加率)이 작을수록 큰 값을 나타냈고, 또 과압밀 영역에서는 하중증가(荷重增加)에 따라 일침압밀완자점(一沈壓密完子點)의 시간(時間)은 큰 값을 나타내고 정규압밀(正規壓密)영역에서는 거의 일정(一定)한 값을 나타냈다. 압밀계수(壓密係數)는 재하량(載荷重)이 증가(增加)함에 따라 감소(減少)하며 하중증가율(荷重增加率)이 클수록 압밀계수(壓密係數)의 값도 크게 나타났다. 이침압밀비(二次壓密比)의 값은 곡연(曲緣)의 변곡점(變曲點)과 거의 일치(一致)되는 점(點)에서 최대(最大)로 되었다. The following is the result of experiment on consolidation test under various load increment ratios by alternation of standard load increment ratio. The more load increment ratio was, the more settlement was resulted. But expansions were not associated with load increment ratios. Primary consolidation took longer period to complete as load increment ratio was decreased. And under the condition of over-consolidated range, the completion of primary consolidation took longer period as the load was incremented. Under the condition of normal consolidated range, there was no change in time of completing primary consolidation. The coefficient of consolidation was decreased with increment of consolidation load, and the coefficient of consolidation had high values as the load increment ratio was increased. The values of ratio of secondary consolidation was highest near the transition point of consolidation curve.

화강암질풍화토(花崗岩質風化土)의 Consistency 측정(測定)에 관한 연구(硏究)

강예묵,조성섭,홍순필,Kang, Yea Mook,Cho, Seung Seup,Hong, Soon Pil 충남대학교 농업과학연구소 1980 Korean Journal of Agricultural Science Vol.7 No.2

Slump시험(試驗)보다는 조작(操作)이 간편(簡便)한 유통(流動) Table을 사용(使用)하여 화강암질풍화토(花崗岩質風化土)의 유동한계(流動限界)를 측정(測定)하는 방법(方法)을 시험(試驗)하여 다음과 같은 결론(結論)을 얻었다. 1) 화강암질풍화토(花崗岩質風化土)의 유동한계(流動限界)는 입도분포(粒度分布), 퐁화도(風化度) 및 유색광물함량(有色鑛物含量)에 영향(影響)되므로 유동(流動) Table에 의한 유동한계시험법(流動限界試驗法)을 제정(制定)할 때는 최대입경(最大粒徑)이 규정(規定)되어야 할 것으로 생각된다. 2) 유동(流動) Table의 낙하회수(落下回數)를 10회(回)로 하여 유동고(流動高)와 유동폭(流動幅)이 1cm일 때의 함수비(含水比)의 평균치(平均値)를 유동한계(流動限界)로 택(擇)하면 Slump시험(試驗)에서 구(求)한 유동한계(流動限界)보다 약간 작은 값으로 되며 대략(大略) 10%오차한계선내(誤差限界線內)에 속(屬)했다. 3) 유동폭(流動幅)과 함수비(含水比) 및 유동고(流動高)와 함수비(含水比)의 관계곡선(關係曲線)은 유사(類似)한 변화(變化)를 나타내고 반대수용선(半對數用線)에 도시(圖示)하면 액성한계시험(液性限界試驗)에서와 같이 직선관계(直線關係)를 나타냈다. 4) Slump시험(試驗)에 비(比)하여 조작(操作)이 간편(簡便)하고 개인적(個人的)인 오차(誤差)가 작으며 유동폭(流動福)과 유동고(流動高)를 동시측정(同時測定)하여 시험오차(試驗誤差)가 작은 것으로 공학적(工學的) 성질(性質)을 판단(判斷)하는 자료(資料)로 사용(使用)될 수 있는 것으로 생각된다. This test was carried out to present criterion to measure the liquid limit of weathered granite soil by using the flow-table method whose operation is easier and more convenient than slump test. The results are as follows. 1. Since liquid limit of weathered granite soil depends upon the particle size distribution, weatheredness and content of colored minerals, maximum particle size should be prescribed when the testing rule of liquid limit by flow-table method is enacted. 2. If take the averaged water content as liquid limit where the height and width of flow are 1 cm respectively by 10 times dropping, this liquid limit is slightly less than the one by slump test. The differance of liquid limit between flow table method and slump test is about 10%. 3. Correlation curves of flow width-water content and flow hight-water content show similar shapes. Those are straight lines in semi-logarithm paper just as liquid limit test. 4. This flow-table method is more convenient and has less personal error of measurement than slump test does. So flow-table method would be favourably utilized for judging the engineering properties of soil.

흙의 지수적(指數的) 특성(特性)에 관한 연구(硏究)

강예묵,조성섭,김성완,Kang, Yea-mook,Cho, Seung-seup,Kim, Seung-wan 충남대학교 농업과학연구소 1977 Korean Journal of Agricultural Science Vol.4 No.2

한강하류(漢江下流), 아산만(牙山灣), 금강하류(錦江下流)및 낙동강하류(洛東江下流) 지역(地域)에 대(對)한 Atterberg한계치(限界値)와 교란(攪亂)된 흙과 교란(攪亂)되지 않은 흙에 대(對)한 역학적(力學的) 성질(性質)을 규정(規定)하는 여러가지 토질상수치(土質常數値)의 상관성(相關性)을 분석(分析)하여 다음과 같은 결과(結果)를 얻었다. 1. 자연상태(自然狀態)의 흙에 단위체적중량(單位體積重量)은 함수비(含水比)를 좌우(左右)하는 성분(成分)인 점토광물(粘土鑛物)의 함유량(含有量)에 의하여 변화(變化)하는 것으로 생각된다. 따라서 습윤단위중량(濕潤單位重量)은 점토광물(粘土鑛物)의 함유량(含有量)이 가장 많은 낙동강하류(洛東江下流)에서 가장 작은 값을 나타내고 한강하류(漢江下流), 금강하류(錦江下流), 아산만(牙山灣)의 순(順)으로 큰 값을 나타냈다. 2. 함수비(含水比)가 증가(增加)하면 건조밀도(乾燥密度)는 감소(減少)하는 곡선관계(曲線關係)가 성립(成立)하며 건조밀도(乾燥密度)의 값은 조립토(粗粒土)의 함유량(含有量)이 많은 아산만(牙山灣)에서 가장 컸고 금강하류(錦江下流), 한강하류(漢江下流) 및 낙동강하류(洛東江下流)의 순(順)으로 나타났다. 3. 각지역(各地域)의 액성한계(液性限界)와 소성지수(塑性指數)의 값은 액성한계(液性限界)의 값이 40% 이상(以上)에서는 소성도(塑性圖)의 A-선(線)보다 위에 있었다. 4. 건조밀도(乾燥密度)는 공극비(空隙比)의 증가(增加)에 따라 감소(減少)하는 곡선관계(曲線關係)가 성립(成立)하며 조립토(粗粒土)의 함유량(含有量)이 많은 흙에서 변화(變化)의 폭(幅)이 컸다. 따라서 공극비(空隙比)의 증가(增加)에 따라 건조밀도(乾燥密度)의 감소(減少)하는 경향(傾向)은 점토함유량(粘土含有量)이 가장 작은 아산만(牙山灣) 지역(地域)에서 가장 큰값을 나타내고 금강하류(錦江下流), 한강하류(漢江下流) 및 낙동강하류(洛東江下流)의 순(順)으로 나타났다. These experiments were carried out to analyse the correlation among various soil parameters which characterize the mechanical properties of the disturbed and undisturbed soil, and to analyse Atterberg Limits for the basin of downstream of Hanriver Keum river, Nakdong river, and Asan bay. 1. Wet density of soil was the lowest in the basin of Nakdong river which contains the highest amount of clay minerals among the soil samples, and was increased in the order of Han river, Keum river and Asan bay. It was appeared that the unit weight of natural soil was changed in accordance with the clay mineral content which determines the moisture content. 2. Curved relationship was recognized, showing that dry density of soil was decreased with increasing the moisture content. Soils from the basin of Asan bay were appeared to have the highest dry density and the next was those of Keum river, the second lowest Han river, and the lowest Nakdong river. 3. When the liquid limit of soils was over 40 percent, their plastic index was above the A-line of plastic chart. 4. Between dry density and void ratio of soils, a curved relationship was found, in which dry density was decreased as void ratio increased, and the differences between them became greater in soils containing higher amount of coarse grained soil. Decreasing tendency of dry density in accordance with increase of void ratio was the most significant at Asan bay which contained the lowest clay content, and other decreasing order of dry density was Keum river, Han river, and Nakdong river.

사면(斜面)의 안정해석(安定解析)에 관(關)한 연구(硏究)

강예묵,조성섭,Kang, Yea Mook,Cho, Seung Seup 충남대학교 농업과학연구소 1981 Korean Journal of Agricultural Science Vol.8 No.2

흙댐 및 자연사면(自然斜面)의 안정해석(安定解析)에 가장 많이 사용(使用)되는 Fellenius방법(方法)과 Bishop방법(方法)을 비교검토(比較檢討)하여 다음과 같은 결과(結果)를 얻었다. 1. 정상침투상태(定常浸透狀態)에서 Bishop방법(方法)이 Fellenius 방법(方法)보다 안전율(安全率)이 11~29%정도(程度) 큰 값을 나타냈다. 2. Bishop방법(方法)이 Fellenius방법(方法)보다 안전율(安全率)이 증대(增大)되는 비율(比率)($F_B-F_F/F_F$)은 경사면(傾斜面)의 기울기가 느릴수록 감소(減少)하는 경향(傾向)을 나타냈다. 3. 침투(浸透)가 없을때와 있을때의 안전율(安全率)이 증대(增大)되는 비율(比率)($F_1-F_2/F_2$)은 경사면(傾斜面)의 기울기가 느릴수록 증가하는 경향(傾向)을 나타냈다. This paper has been prepared to compare the safety factor of Fellenius method and Bishop method which are most frequantly utilized for stability analysis of dam and natural slope. The results are as follows. 1. Safety factor obtained by Bishop method shows 11-29% higher in steady seepage state and 46-57% higher in no seepage flow than the one by Fellenius. 2. The ratio of safety factor between no seepage flow and seepage flow ($F_1-F_2/F_2$) increases as the slope becomes flatter. 3. The ratio of safety factor between Bishop method and Fellenius ($F_B-F_F/F_F$) decreases as the slope becomes flatter.

흙의 다짐에 있어서 최대건조밀도(最大乾燥密度)와 최적함수비(最適含水比)의 추정(推定)에 대(對)하여

강예묵,조성섭,김재영,Kang, Yea-Mook,Cho, Seung-Seup,Kim, Jae-Young 충남대학교 농업과학연구소 1976 Korean Journal of Agricultural Science Vol.3 No.2

최대습윤밀도(最大濕潤密度)로서 함수비시험(含水比試驗)을 하지 않고 직접최적합수비(直接最適合水比)와 최대건록밀도(最大乾綠密度)를 추정(推定)하는 관계식(關係式)을 구(求)하기 위(爲)하여 전국(全國)에서 최근(最近)에 공사(工事)를 실시(實施)하였거나 또는 공사중(工事中)에 있는 157개(個) 지구(地區)의 다짐시험(試驗) 결과(結果)를 분석(分析)하여 다음과 같은 결론(結論)을 얻었다. 최대건조밀도(最大乾燥密度)와 최적합수비(最適合水比)의 사이에는 ${\gamma}=0.9636$의 높은 상관성(相關性)을 나타냈고 ${\gamma}_{dmax.}={\frac{1}{0.4193+0.00937W_{opt.}}$의 관계식(關係式)을 얻었다. 최적합수비(最適合水比)에 대응(對應)하는 습윤밀도(濕潤密度)와 최적합수비(最適合水比)는 $W_{opt.}={\frac{1-0.4193{\gamma}_{tmax.}}{0.937_{\gamma}_{tmax.}-0.01}$의 관계식(關係式)을 얻었고 최대습윤밀도(最大濕潤密度)(${\gamma}_{tmax}$)로 추정(推定)한 최적합수비(最適合水比)는 실측치(實測値)와 큰 차이(差異)가 없었다. 최대습윤밀도(最大濕潤密度)로 추정(推定)한 함수비(含水比)에 의하여 최대건조밀도(最大乾燥密度)를 추정(推定)한 결과실측치(結果實測値)와의 오차(誤差)는 ${\pm}5%$내(內)에 속했다. 최대건조밀도(最大乾燥密度)와 공극비(空隙比)는 ${\gamma}=0.9706$의 높은 상관성(相關性)이 인정(認定)되고 ${\gamma}_{dmax.}={\frac{1}{0.3938+0.3426e}}$의 관계식(關係式)을 얻었다. In order to obtain the prediction of the maximum dry density and the optimum moisture content of soil without soil moisture test, compaction test results from 157 different places either under construction or already completed were analyzed. The analyzed results were as follow The relationship between the maximum dry density and the optimum moisture content of the soil showing a correlation coefficient of 0.96 indicated that there was a high correlation between them. From the above relationship we obtained the equation, ${\gamma}_{dmax.}={\frac{1}{0.4193+0.00937W_{opt.}}$ Equation between the optimum moisture content and the maximum wet density of the soil was $W_{opt.}={\frac{0.4193{\gamma}_{tmax.}}{0.937_{\gamma}_{tmax.}-0.01}$, and the values of the optimum moisture content being predicted with the maximum wet density of the soil showed a little difference between those and tested values. The values of the maximum dry density being predicted with the moisture content estimated by the maximum wet density of the soil were within the range of ${\pm}5%$ of its tested values. The relationship between the dry density and the void ratio showed a high correlation between them (${\gamma}=0.9706$). From the above relationship, we obtained the equation, ${\gamma}_{dmax.}={\frac{1}{0.3938+0.3426e}}$.

지진계수(地震係數)를 고려(考慮)한 제방(堤防)의 사면안정(斜面安定)에 관(關)한 연구(硏究)

강예묵 ( Kang Yea Mook ),지인택 ( Chee In Taeg ),이달원 ( Lee Dal Won ) 한국농공학회 1991 韓國農工學會誌 : 전원과 자원 Vol.33 No.4

This study was performed to investigate the minimum safety factor of embankment in consideration of seismic coefficient by the psuedo-static analysis The variables were cohesion, the internal friction angle, angle of slope, height of seepage, height of embankment, depth of replacement The results obtained were compared with those by Fellenius method, simplified Bishop method and Janbu method. The results were summarized as follows: 1. The increasing rate of the minimum safety factor with the increasing of cohesion appeared larger in Fellenius method and Bishop method than in Janbu method. And that with the increasing of the internal friction angle appeared the lowest value in Janbu method. The minimum safety factor was influenced larger on the internal friction angle than on cohesion. 2. The variation of the minimum safety factor with the height of seepage at 0m and 5 m was nearly similar to Fellenius method, Bishop method and Janbu method. On the other hand, it was decreased suddenly at 25 m. 3. The minimum safety factor with the height of embankment was decreased remarkably under 10 m with the increasing of seismic coefficient. But, it was decreased slowly more than 10 m. As the height of embankment was low, the influence of cohesion appeared larger. 4. In heigher case of the depth of replacement, the phenomenon of reduction of the minimum safety factor appeared remarkably with seismic coefficient increased. And in lower case of the depth of replacement, the minimum safety factor was similar in Fellenius method and Bishop mehtod. But it appeared larger in Bishop method and Janbu method than in Fellenius method with the depth of replacement increased. 5. As the cohesion and the internal friction angle were large, the phenomenon of reduction of the minimum safety factor with the increasing of seismic coefficient appeared remarkably. Also, the influence of seismic coefficient in minimum safety factor appeared larger with the soil parameter increased. 6. When the seismic coefficient was considerated, investigation of the structural body on the slope stability appeared profitably in Fellenius method and Janbu method than in Bishop method.

사면(斜面)의 안정해석(安定解析)에 관한 연구(硏究)

강예묵 ( Kang Yea Mook ),조성섭 ( Cho Seong Seup ),지인택 ( Chee In Taeg ) 한국농공학회 1989 韓國農工學會誌 : 전원과 자원 Vol.31 No.1

The paper compared the Bishop methed to the Fellenius method in the analysis of slope stability. Laboratory model test was carried out in the case of seepage flow considered. The results obtained from this study were summarized as follows; 1. The slice pieces of 10 were enough to analysis the slope stability. 2. The safety factor by the Fellenius method was lower than the Bishop method by the 96 to 97% in the case of no seepage flow and by the 95 to 96% in the case of seepage flow considered. 3. Besides the parameter of soil and slope, the safety factor of slope was influenced by the height of slope. This phenomena was distinct in the height of height less than 10 meters. 4. In the case of clay, there was no difference in the safety factor of slope between Fellenius and Bishop method. The safety factors of slope with the seepage flow considered were lower than those with no see-page flow. 5. The influence of cohesion on the safety factor was more significant in the Bishop method than in the Fellenius method. 6. The slope failure of model test of A and B soil samples with high permeability coefficient was taken place slightly in vicinity of toe by the concentration of stress and gradually increased. 7. Under condition of same slope height, the shapper the slope, the shorter the radius and the center of critical circle appered downward and finally failure of slope occured inside the slope.

壓密 特性에 關한 研究(Ⅱ)

姜乂默(Yea-Mook Kang),柳能桓(Neung-Hwan Ryu) 충남대학교 농업과학연구소 1977 農業技術硏究報告 Vol.4 No.1

斜面의 安定解析에 關한 研究

姜乂默(Yea Mook Kang),趙成燮(Seung Seup Cho) 충남대학교 농업과학연구소 1981 農業技術硏究報告 Vol.8 No.2

현장계측에 의한 연약지반 성토의 안정관리 기법

강예묵 ( Kang Yea Mook ),이달원 ( Lee Dal Won ),김지훈 ( Kim Ji Hoon ),김태우 ( Kim Tae Woo ),임성훈 ( Lim Seong Hun ) 한국농공학회 1999 韓國農工學會誌 : 전원과 자원 Vol.41 No.2

A series of field tests were performed to suggest a rational method for the stability evaluation of soft clay. The behavior of settlement-displacement obtained by field monitoring system was used to compare and analyze with various stability evaluation methods, and to investigate the applicability of the methods for stability evaluation of soft clay. The limit equilibrium method, numerical analysis and field monitoring methods were used to analyze the stability evaluation. The horizontal displacement was abruptly increased when physical properties of soft clay reached its maximum values and therefore, the values of these properties could be used to the fundamental data for stability evaluation. The evaluation of the stability of clay embankment was suggested to use inclination of curve rather than critical line, and the minimum safety factor of 1.2 or larger for natural clay was recommended. Therefore, the evaluation of short term stability of soft clay could be effectively performed with the hyperbolic model and the field monitored data.