• Land and Housing Review
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• v.3 no.1
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• pp.97-109
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• 2012

For the design of underpass structures, -1.0m(G.L) ground water level guideline for the design of railway, subway, utility tunnel etc, is still being used in Korea. As a result, the underpass structure can be forced by buoyancy, and therefore the in-situ buoyancy anchor method is usually being applied to prevent the uplifting force. For the Yeongjongdo sky city project, the drainage method was applied to remove the buoyancy force. In this study we estimate the efficiency and safety of the applied design and propose the detailed guidelines for standard design and maintenance of the guided drainage technique. Especially, the auxiliary pumping well was operated to maintain the ground water level around the underpass. In the study site, the applied guided drainage method has advantages in both engineering and economic aspects.

• Journal of Korea Water Resources Association
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• v.54 no.1
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• pp.49-60
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• 2021

This study presents a methodology to estimate two distinct fractal dimensions of natural river basin by using fractal tree concept. To this end, an analysis is performed on fractal features of a complete drainage network which consists of all possible drainage paths within a river basin based on the growth process of fractal tree. The growth process of fractal tree would occur only within the limited drainage paths possessing stream flow features in a river basin. In the case of small river basin, the bifurcation process of network is more sensitive to the growth step of fractal tree than the meandering process of stream segment, so that various bifurcation structures could be generated in a single network. Therefore, fractal dimension of network structure for small river basin should be estimated in the form of a range not a single figure. Furthermore, the network structures with fractal tree from this study might be more useful information than stream networks from a topographic or digital map for analysis of drainage structure on small river basin.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.4
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• pp.87-96
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• 2019

The objective of this study was to develop a general inundation modeling technique considering the effect of drainage delay in the paddy field districts. In most studies, farmland inundation simulations have been conducted using previously developed watershed models. However, the water cycle in the paddy fields has a different structure from that of the general watershed, and the effect of the drainage delay should be considered. In this study, the drainage delay algorithm was developed using water balance equation, and the inundation modeling was performed for inundation-prone paddy fields located near Doowol stream. As a result, the depth of inundation was 43.1 cm and 45.2 cm, respectively, due to the 100-year and 200-year frequency rainfall. With the operation of drainage pump ($0.1m^3/s$), inundation depths decreased by 5.8 cm and 6.0 cm, respectively, and inundation time reduced by 20 hours and 21 hours, respectively for the 100-year and 200-year frequency rainfall. The result showed that the general inundation modeling technique developed in this study could reflect the effect of drainage delay due to the rise of external water level and the flooding reduction effect by operation of drainage pump. The results of this study are expected to be useful to establish measures for damage caused by farmland inundation.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.4
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• pp.669-683
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• 2017

The objective of this study is to propose a modification of the previously proposed drainage system for catching the partial leakage of underground concrete structures. Two techniques were proposed for applying the drainage system only to the leaking parts. One was for conveying leaking groundwater to the collection point in the drainage system and the other was for conveying the collected groundwater to the primary drainage system of the underground concrete structure. Four waterproofing materials for conveying leaking groundwater to the catchment point of the drainage system, Durkflex made of porous rubber material, KE-45 silicone adhesive with super strong adhesion, Hotty-gel made of polymeric materials and general silicone adhesive were evaluated for waterproofing performance. Hotty-gel only showed perfect waterproof performance and the other three waterproof materials leaked. The modified drainage system with Hotty-gel and drainage pipe with fixed saddle to convey the leaking groundwater from the catchment point to the primary drainage system were tested on the concrete retaining wall. The waterproof performance and the drainage performance were evaluated by injecting 1,000 ml of water in the back of the modified drainage system at the 7-day, 14-day, 21-day, 28-day, 2-month and 3-month. There was no problem in waterproof performance and drainage performance of the modified drainage system during 3 months. In order to evaluate the construction period and construction cost of the modified drainage system, it was compared with the existing leaching repair method in surface cleaning stage, leakage treatment stage, and protective barrier stage. Total construction period and construction cost were compared in considering the contents of work, repair material, construction equipment, working time, and total number of workers. As a result of comparing and analyzing in each construction stage, it was concluded that the modified drainage system could save construction period and construction cost compared to the existing leaching repair method.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.878-883
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• 2005

This paper describes the effect of acid rock drainage(ARD) produced from the cut slope on the slope structures. Acid rock drainage is originated from a rock quarry located in coal mine zone and mineralization belt of Chosen Supergroup and Ogcheon group, andesite with the pyrite, and acid sulfate soils of Tertiary in Korea. The cut slope, where acid rock drainage comes out, almost has been constructed by shotcrete and planting works. According to the field observation results, in most cases, the acid rock drainage has an adverse effect on slope structures. The shotcrete, anchors and rock bolts produced corrosive action, and bad germination and growth diseases of covering plants of the slope planting construction due to ARD.

• KCID journal
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• v.11 no.1
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• pp.87-98
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• 2004

• Journal of the Society of Disaster Information
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• v.14 no.2
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• pp.165-173
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• 2018

Purpose: The area such as historic sites where distributed in the hills surrounded by the mountains in the past, if heavy rains occur, soil that distributed in the substructure of a sedimentary layer's permeability decreases therefore, water do not smoothly drainage and increases surface structures' moisture content. Therefore, many phenomena occur such as the muddy ground. This experiment tried to figure out the cause of poor drainage, predicting poor drainage system when rainfall occur. So not only the base of cultural properties distributed in the historic site, but also have big influences on the upper structure. Method: We are going to propose an improvement plan through the various sites exploration and the field permeability test. In addition, analyze interrelationship to figure out the cause of the poor drainage through monitoring under ground water. Conclusion: As the result of the experiment, the cause of the poor drainage system formed on shallow depth of ground level inside of a land. We can see that soil of surface and fill deposit permeability was in poor condition. Therefore, it was in very inappropriate hydrogeological condition when surface water permeate into the underground when rainfall occurs.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.125-131
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• 2011

This research aims to investigate the cause of the occurrence of a weak road drainage section scientifically and specifically through a site survey for a poorly drained section occurring due to rainfalls during road operation. This paper deeply reviewed the existing research results and current situation data on the poorly drained sections accumulated in Korea Expressway Corporation in order to investigate the cause of the occurrence of a weak road drainage section, and deeply verified and analyzed the weak sections for the road surface drainage facilities and the other road drainage facilities by visiting the expressway controlled by the 6 local headquarters and 33 branches of Korea Expressway Corporation. As a result of site surveys for the weak road drainage sections, i) in a road surface section, occurrence of ponding in the road shoulder pavement due to slope changes, bad collection of water in the collecting well at a median strip, shortage of road shoulder dike height, and inferior construction, etc. was analyzed to be the main cause of the occurrence of poorly drained sections, and ii) in a road neighborhood section, the occurrence of pavement height difference in a main road and shoulder section due to inferior ditches on a slope and the bad drain age at the inlet and outlet of a culvert due to soil deposits, debris, etc. were analyzed to be the main cause of the occurrence of weak sections. Proposed as a plan to improve the poorly drainage section of road were i)calculation of capacity through material changes at the ditch, enhancement of vertical sections and hydraulic analysis in terms of construction and other aspects, ii)derivation of a combined slope considering a slope and a vertical linearity and maintenance of proper distance between drainage structures in a vertical concave section in terms of geometrical structure, and iii)calculation of the drainage facility installation interval using a minutely rainfall intensity formula and a non-uniform flow analysis technique in terms of hydraulics and hydrologics and prompt removal of rainfalls from the road surface according to a linear drainage method.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.124-141
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• 2019

This research explored the relationship between the water quality issue of Wolji Pond (Anapji Pond) with the maintenance of the channel flow circulation system. The water supply and drainage system closely related to the circulation system of pond has been reviewed, rather than the existing water supply and drainage system that has been analyzed in previous studies. As a result of reviewing the water supply system, it has been learned that the water supply system on the southeastern shore of Wolji Pond, being the current water supply hole, has been connected to the east side garden facility (landscaping stone, curved waterway, storage facility of water) between the north and south fence and the waterway. This separate facility group seems to have been a subject of the investigation of the eastern side of Wolji Pond, with the landscaping stones having been identified in the 1920's survey drawings. The water supply facility on the southeastern shore, being the suspected water supply hole, seems to have some connection with the granite waterway remaining on the building site of Imhaejeon (臨海殿) on the southern side of Wolji Pond. It is inferred that it provides clean water, seeing that the slope towards the southwestern shore of Wolji Pond becomes lower, the landscaping stones have been placed in the filter area, and it is present in the 1920's survey drawings and the water supply hole survey drawing of 1975. The water drainage facility on the northern shore is composed of five stages. The functions of the wooden waterway and the rectangular stone water catchment facility seem not to be only for the water drainage of Wolji Pond. In light of the points that there are wood plugs in the wooden waterway and that there is a water catchment facility in the final stage, it is judged that the water of Balcheon Stream (撥川) may be charged in reverse according to this setup. Namely, the water could enter and exit in either direction in the water drainage facility on the northern shore It also seems that the supply to the wooden waterway could be opened and shut through the water catchment facility of rectangular stone group as well. The water drainage facility on the western shore is very similar to the water drainage facility on the northern shore, so it is difficult to avoid the belief that it existed during the Silla Dynasty, or it has been produced by imitating the water drainage facility on the northern shore at some future point in time. It seems to have functioned as the water drainage facility for the supply of agricultural water during the Joseon Dynasty. The water supply and drainage facilities in Wolji Pond have been understood as a systematized distribution network that has been intertwined organically with the facility of Donggung Palace, which was the center of the Silla capital. Water has been supplied to each facility group, including Wolji Pond, through this structure; it includes the drainage system connecting to the Namcheon River (南川) through the Balcheon Stream, which was an important canal of the capital center.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.1
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• pp.26-32
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• 2000

The impact of major surface chemical properties of silica sols on the retention and drainage performance of the silica based micrparticle system, Compozil was investigated using four different silica sols. And the effect of silica properties on the interactions with cationic starch and cationic plyacrylamide has also been identified. The surface charge density and the stability over pH of silica sols were increased by introducing aluminosilicate anions at surface. It was found that the charge density of silica sols determined the addition level necessary to attain the maximum retention and drainage. When silica sols were combined with cationic starch, the change density of the product was the critical properties and the degree of microagregation was of minor importance. In the cationic polyacrylamide system the degree of colloid structure appeared to be a more critcial property than the charge density of silica sols.