흙댐의 밀도변화에 의한 압밀침하에 대한 연구

윤충섭 한국농공학회 1986 한국농공학회논문집 Vol.28 No.3

This study was carried out for the settlement and camber of earth dam by the changes of the density. The testing material was taken five kinds of Soil used as banking material and it was compacted by 100, 95, 90, 85 and 80% compaction degree. The results of the settlement of earth dam whose height ranges from 10m to 50m are as follows. 1.The more the fine particle (n) increases, the higher the liquid limit (WL) and the lower the dry density (rd) becomes as follows; rd=2. 22-0. 0052n (gr/cm$_3$) rd=2. 394-0. 0164WL rd=2. 185-(5. 8n-2. 5WL)X10-$_3$ 2. The higher the optimum moisture content (Wo) becomes, the lower the density becomes as follows; rt,=2. 68-0. 028Wo rd=2. 578-0. 04Wo 3. 3.Most of the consolidation occurs immediately by loading and the more the fine particle increases, the lower the coefficient of consolidation becomes. 4.The more the fine particle increases and lower the compaction degree (D) becomes,the lower the pre-consolidation load (Pc) becomes but on the contrary the compression index (Cc) becomes higher. Those equation is as follows. Pc=3. 32-(4. 3n-3. 0D) X10-2 (kg/cm$^2$) Cc=0. 41+(1. 33n-4. 44D) X10-$^3$ 5.The more the consolidation load (P) increases, the lower the coefficient of volume change (mv) becomes with mv=ap-b, the higher the consolidation ratio (u) becomes with U= (0. 6~1. 35)PO.4 6.The more the fine particle (n) increases, the more the settlement of dam occurs with U=anb and 60-80% of the settlement occurs under construction. 7.The camber of dam has higher value in condition that has more fine particle, poorer compaction and higher height of dam. In the dam construction about twice value of table 7 is required for dam safety.

흙댐의 다짐밀도가 안정도에 미치는 영향에 관한 연구

윤충섭,김시원 한국농공학회 1989 한국농공학회논문집 Vol.31 No.1

This study was carried out for the stability analysis of earth dam by the variation of compaction density. The test samples were taken from five kinds of soil used for banking material and the degree of compaction for this samples were chosen 100, 95, 90, 85, and 80 percent. The stability problems were analysed by the settlement and camber( extra banking) of dam, strength parameter and dam slope, and coefficient of permeability and seapage flow through dam body. The results of the stability analysis of earth dam are as follows. 1. The more the fine particle increases and lower the compaction degree becomes, the lower the preconsolidation load becomes but the compression index becomes higher. 2. Sixty to eighty percent of settlement of dam occurs during the construction period and the settlement ratio after completion of dam is inversly proportional to the degree of compaction. 3. The camber of dam has heigher value in condition that it has more fine particle(N) and heigher dam height(H) with the relation of H= e(aN-bH-e). 4. The cohesion(C) decreases in proportion to compaction degree(D) and fine particle(N) with the relation of C= aD+ bN-c, but the internal friction angle is almost constant regardless of change of degree of compaction. 5. In fine soil, strength parameter from triaxial compression test is smaller than that from direct shear test but, they are almost same in coarse soil regardless of the test method. 6. The safety factor of the dam slope generally decreases in proportion to cohesion and degree of compaction but, in case of coarse soil, it is less related to the degree of compaction and is mainly afected by internal friction angle. 7. Soil permeability(K) decreases by the increases of the degree of compaction and fine particle with relation of K=e(a-bl)-cN) 8. The more compaction thickness is, the less vertical permeability (Kv) is but the more h6rzontal permeability (KH) is, and ratio of Kv versus KH is largest in range from 85 to 90 percent of degree of corn paction. 9. With the compaction more than 85 percent and coefficient of permeability less than ${\alpha}$X 10-$^3$cm/sec, the earth dam is generally safe from the piping action.

배수시공을 위한 국제관개배수위원회(ICID)기준 -110(지하수배시공)-

윤충섭 한국농공학회 1982 한국농공학회논문집 Vol.24 No.4

Dynamic Consolidation에 의한 연약지반의 개량

윤충섭 한국농공학회 1982 한국농공학회논문집 Vol.24 No.1

Fill Dam의 기계 전압효과에 관한 연구

윤충섭,김주범 한국농공학회 1979 한국농공학회논문집 Vol.21 No.3

The compaction of core zone of the fill dam is very important foe increasing of the Strength of soil mass and reduction of permeability of the core. The principal objects of this study are to give the construction criteria of tamping rollers and to find out the relationships between density and permeability of soil after compaction. The results in this study are summarized as follows. 1. The core zone of fill dam should be compacted more than 8 passed because the compaction effects of clayey soil increase sharply in about 8 passes of roller. 2. The coefficient of permeability (K) increases with the thickness of compaction of soil even though the density is same. 3. The effect of compaction increases with the quantity of coarse materials such as coarse sand and gravel. 4. If D values change from 100 percent to 98 percent and from 100 percent to 95 percent, K values become 2 times and 5 times of initial K value respectively. 5. The coefficient of permeability in the field soil is very high comparing with the result of laboratory test at the same 100 percent compaction ratio, but differences between both results decrease with the decrease of compaction ratio. 6. Thickness of soil layer for the compaction should be increased for heavier compaction machine. 7. In order to get the compaction ratio of 98 percent or more, 10 to 12 passes of roller is generally required with the thickness of soil from 20cm to 30cm.

투수성 성토재료의 기계다짐에 관한 연구

윤충섭 한국농공학회 1981 한국농공학회논문집 Vol.23 No.3

The Compaction of fill dam is very important for increasing of the safty of dam. Vibration roller is used for the compaction of pervious materials such as sand and gravel. The principal objects of this study are to give a comstruction criteria of vibration roller and to find out the relationship between dry density and permeabity of pervious soil after compaction. The results in this study are summerized as follows. 1.The relationship between maximum dry density (Υdmax) and optimum moisture content(Wo) of modified compaction test is Υdmax=2. 74-0. 064w0 2.The maximum dry density decrease with increasing fine particle(n) and the relative formular is n==ae-brdmax 3.The maximum dry density is influenced more by passing rate of number 200 sieve than 4 sieve. 4.The coefficient of permeability are similar when the degrees of compaction are equal even though the spreading thickness of soil are different. 5.The coefficient of permeability(K)is greatly influence by fine particle passing number 200 sieve, and those relationship is inversely proportionate. 6.The K values of pervious soil are from 10-0 cm/sec to 10-4 cm/sec when degree of compaction by a modified method is from 90 to 95percent. 7.The coarser material is little influenced on the permeability with different density. 8.The increasing rate of permeability with decreasing degree of compaction is more influened by fine pacticle than number 200 sieve. When degree of compaction decrease from 100 percent to 90 percent the K values of SM and GM increase about 20 times but GW increase 6 times only. 9.The effect of compaction by vibration roller is greatly influenced by 6 passes and the increasing rate of the effect is decraased at 8 passes. 10. In order to get the degree of compaction of 95 percent or more, 6 to 8 passes of roller are generall required with 30 cm thickeness of soil for 4.5 ton to 6.5 ton vibration roller and 7 to 8 passes is required with 50cm thickness for 8 to 12 ton roller.

흙의 다짐과 Consistency에 관한 연구

윤충섭 한국농공학회 1976 한국농공학회논문집 Vol.18 No.4

In the construction of earth dam, embankment and highway by filling, a compaction contributes to increasing the density of soil by applying pressure. The effect of compaction depends on various factors such as soil type, moisture content, gradation, consistency, and compaction energy. In this study, the correlations amone maximum dry density, moisture content, dry density, and moisture content are analyzed. Some results obtained in this study are summarizep as follows. 1. The maximum dry density sinoreases with increased of optimum moisture content and the correlations of them can be represented by; ${\gamma}$dmx=a-b(W0) 2. Maximum dry density and liquid limit show negative linear correlation and can be represented by; ${\gamma}$dmx=a-b(LL). 3. Optimum moisture content and liquid limit, plastic limit show positive linear correlation and can be represented by the following equation, W0=a+b(LL) W0=a+b(PL). 4. Liquid limit and plastic limit show positive linear correlation, and can be represented by the following equation, LL=a+b(PL).

축제용 흙의 밀도변화에 의한 투수계수에 관한 연구

윤충섭 한국농공학회 1973 한국농공학회논문집 Vol.15 No.1

The density of soil is one of the most important of its engineering properties, and many soil-engineering operations directed toward improving the density characteristics of matecal. This report is a study on relationship between density, permiabilty and other physical properties of compacted soil in various desity grades. The results of the study can be summariged as follow: 1. The optimum moisture content of soil increses with increasing of fine particles and a relationship between both parameter is $w_0=0.1765.n$ Where, n is passing percentage from #200 sieve. 2. The porosity of soil increases with increasing of optimum water content as $e=aw_0+b$ without having relation to compaction ratio. 3. The increment of permeability of soil is high when the compaction ratio is increased and the phenomenon is conspicuous in case of course soil and non-plastic soil. 4. The permeability of soil decreases with increasing of optrimum water content and the phenomenon is conspicuous when compaction ratio decreases. And the permeability is almost constant when optimum water content is more than 25 percent, even though compaction ratio changes. 5. The permeablity of soil increanses when the amount of fine particles is very few, the permeability is almost constant as being impervious condition without having relation to compaction ratio when there in more than 90 percent of fine particles(less than #200 sieve).

농업토목구조물과 토질문제

윤충섭 한국농공학회 1989 한국농공학회논문집 Vol.31 No.2

조립재가 흙의 역학적 성질에 미치는 영향

윤충섭,김호일 한국농공학회 1989 한국농공학회논문집 Vol.31 No.3

The study was carried out for the strength parameter of coarse grained Soil and slope stability analysis of earth dam. The test samples were taken fifteen kinds of soil from cohesive soil to coarse gravel. The degree of compaction of test samples for shear test and permeability test was chosen 95 percentage of maximum dry density. The results of this study are as follows ; 1.The maximum dry density(Yd) of coarse grained soil increase in proportion to coarse particles(P) with the relation of Y d= 1.609+0.0043P. 2.The coefficients of permeability(k) decrease by the increase of fine particles(n) with the relation of k=0.0426e-0 185n. 3.The cohesions of soil decrease by the increase of coarse particles, but internal friction angles are more increased in same condition. 4.The internal friction angles(${\Phi}$) decrease in inverse proportion to void ratio(e) with the relation of ${\Phi}$ = 73.068 - 69.268e. 5.The strength parameters( Ct ${\Phi}$t) by triaxial compression test are clearly smaller than that (Cd, ${\Phi}$d) by direct shear test in fine grained soil, but the differences between both parameters are a little in coarse grained soil.The relations of both parameters are as follows; Ct = O.544Cd + 0.04 ${\Phi}$t= 1.282${\Phi}$d-2306 6.In cohesive soil, the strength parameters( Cl ${\Phi}$l) by large size shear test apparatus are similar to the strength parameters(Cs , ${\Phi}$s) by small size shear test appratus, but Cs and ${\Phi}$s values are larger than Cl and ${\Phi}$l values from 10 percentage to 20 percentage in coarse grained soil. 7.The fine grained soil is inappropriate to high dam more than 20 meters and it must be taken coarse grained soil with high internal friction angle for high dam.