• The Journal of Engineering Geology
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• v.16 no.1 s.47
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• pp.97-107
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• 2006

Or this study, prevailing design and construction methods of dam under various unfavorable conditions are summarized. for example, foundation treatment with large scale alluvium site or weathered rock mass, dam constructing techniques with unfavorable topographic conditions are studied for the better understanding of relating engineers. Also, zoning by using weak rocks and sand-gravel fill techniques are summed up.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.836-841
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• 2008

CFRD (Concrete Faced Rockfill Dam) has been world-widely constructed due to a lot of advantages compared with rockfill dam and recently, sand/gravel materials, instead of crushed rock materials, are also utilized as a main rockfill material to overcome geological and environmental problems. In this paper, the process of water infiltration into the originally unsaturated sand/gravel-fill dam is studied using two-dimensional saturated-unsaturated seepage theory. According to the results of seepage analysis, if the effective drainage zone is installed in the dam, the reservoir water infiltrate into the dam along a downward flow path towards the lower drainage area. The main body constructed with sand/gravel materials, therefore, remains unsaturated.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.818-823
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• 2006

In this study, the suitability of CFGD(concrete faced gravefill dam) was investigated by examining the strength and deformation characteristics of a gravelfill material, a CFGD main fill material, and comparing them with those of several rockfill dam materials. The gravelfill material exhibited similar strength and deformation properties to those of the main fill materials of existing stable large rockfill dams. Since not only CFGD has environmental and economic advantages over CFRD, but its main fill material compares favorably with those of the existing stable CFRDs, CFGD may be the best choice when natural gravel materials are abundant in the vicinity of the dam construction location.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.866-873
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• 2009

CFRD (Concrete Faced Rockfill Dam) has been world-widely constructed due to a lot of advantages compared with rockfill dam and recently, sand/gravel materials, instead of crushed rock materials, are also utilized as a main rockfill material to overcome geological and environmental problems. In this paper, the process of water infiltration into the originally unsaturated sand/gravel-fill dam is studied using two-dimensional saturated-unsaturated seepage theory. According to the results of seepage analysis, if the effective drainage zone is installed in the dam, the reservoir water infiltrate into the dam along a downward flow path towards the lower drainage area. The main body constructed with sand/gravel materials, therefore, remains unsaturated.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.278-287
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• 2009

This thesis studied effect of zoning on seepage flow in concrete faced gravel-fill dam (CFGD) designed to have selected main rockfill or gravel-fill zone, Zone 3Bs with higher permeability to enhance the safety against accidental water infiltration into the dam. For this purpose, centrifuge model tests with two cases, with and without Zone 3Bs, were performed in order to investigate the necessity and the function of Zone 3Bs. Model dams were made by soil samples with modified coefficients of permeability and concrete faced slab was simulated with aluminum alloy. Water infiltration was simulated by rising water table over cracks on the facing. Behaviors of model dams were measured by LVDTs, strain gages, pore water pressures and cameras. Form the results of centrifuge tests, it was found out that the Zone 3Bs acts as a protection of main gravel-fill zone by inducing flow paths for infiltrated water into it as well as by draining off the infiltrated water out of the dam in a short time.

• The Journal of Engineering Geology
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• v.15 no.1
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• pp.77-86
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• 2005

CFRD(Concrete Faced Rockfill Dam) is in widespread use because this type of dam has superior characteristics in structural, material aspects comparing with earth cored rockfill dam. On this paper, up-to-date re-searches and techniques are summed up to be available for future needs in design and construction of CFRD. For example, such items as embankment using weak rock, experience of sand-gravel fill CFRD, connecting slab applied between plinth and face slab, raising experience of old dm, inverse filtration problem, environmental friendly zone, thickness and reinforcing of face slab, alluvial foundation treatment, and curb element method, are summarized for understanding of related engineers.

• Journal of the Korean Geotechnical Society
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• v.24 no.6
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• pp.45-55
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• 2008

CFRD (Concrete Faced Rockfill Dam) has been world-widely constructed due to a lot of advantages which it has compared with rockfill dam and recently, sand/gravel materials, Instead of crushed rock materials, are also utilized as a main rockfill material to overcome geological and environmental problems. In Korea, two dams using sand/gravel materials as a main fill material were designed and are being constructed. In this research, the strength and deformation characteristics of the rockfill and sand/gravel materials taken from 2 dam sites were tested by using a laboratory large triaxial testing equipment for a total of 7 cases. From the results of large triaxial and compaction tests, it was observed that two kinds of materials show a little different compaction, shear strenght and deformation characteristics. It could be expected that the shear strength of sand/gravel material was not disadvantageous compared with that of rockfill materials, however, there was some difference between two materials with respect to behavior characteristics. On the other hand, smaller displacements were observed from numerical analysis based on the data from a large triaxial test when the sand/gravel is used as a main fill material compared with the case when the crushed rock material is used as a main fill material. Finally, in spite of a little different shear strength and behavior characteristic between two materials, it was concluded that it will not lead to a significant problem when the sand/gravel material is used as a main rockfill material.