• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.6
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• pp.67-72
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• 2019

This study compared the theory of a culvert spacing and analytical results of the seepage flow for the subsurface drainage. i) If culvert spacing (Sc) is within 5 m, the unit drainage (q) is very larger; in contrast, if Sc is 5 m or more, there is very little drainage in the middle between drains. Therefore, the drain spacing should be within 5 m to ensure high drainage efficiency. ii) Since the planned culvert drainage increases linearly with the soil's permeability coefficient (k), k must be taken into account when determining the drain diameter by the planned culvert drainage. iii) As a result of analyzing the drainage performance of the absorbing culvert, the drainage performance is sufficient with the diameter of the corrugated drain pipe Dc = 50 mm at the length of the drain Lc = 100 m. iv) Therefore, if the drain spacing (Sc) is less than 5 m using the low-cost non-excavated drainage pipe method (${\Phi}50mm$ the corrugated drain pipe and fiber mat) rather than the conventional trench drain method (Sc > 10 m, Dc > 100 mm), uniform and high drainage efficiency can be ensured as well as low construction cost. v) The sub-irrigation+drainage culvert requires narrower drain spacing (Sc < 2-3 m) for irrigation. As a result of examining the condition of 35 mm in diameter (Dc) and 2~3 m in drain spacing, it is possible to apply the non-excavated drainage pipe method to the sub-irrigation+drainage culvert because drainage performance is sufficient at the drain length Lc = 50 m.

• Advances in concrete construction
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• v.15 no.6
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• pp.377-389
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• 2023

In this study, an improved modular arch system with the lower arch space composed of a precast arch block and an outrigger was proposed as an underground culvert, and its applicability and structural behaviors were confirmed. This modular arch culvert structure with vertical walls was designed using precast blocks and by adjusting the placement spacing of concrete blocks to the upper part form an arch shape and the lower part form a vertical wall shape, based on previously researched modular arch systems. Owing to the vertical wall of the proposed modular arch system, it is possible to secure a load-carrying capacity and an arch space that can sufficiently resist the earth pressure generated from the backfill soil and loading on the arch system. To verify the structural characteristics, and applicability of the proposed modular precast arch culvert structure, a full-scale modular culvert specimen was fabricated, and a loading test was conducted. By examining its construction process and loading test results, the applicability and constructability of the proposed structure were analyzed along with its structural characteristics. In addition, its the structural predictability and safety for the applicability were evaluated by comparing the construction process and loading test results with the FE analysis results.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.6
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• pp.73-81
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• 2018

In this study, subsurface discharge performance has been studied through theoretical seepage analysis on four types of culverts that can be installed under the condition of non-excavation, such as (a)perforated pipe(${\Phi}50mm$), (b)perforated pipe+horizontal mat (B50cm) (c)perforated pipe+horizontal mat+vertical gravel(B<10cm), (d)perforated pipe+vertical gravel(B<10cm), and existing typical type (e)perforated pipe with gravel (B40, h=40cm) which can be installed by excavation. The analysis results were as follows. i) Subsurface discharge performance per unit (m) was (a)type 56%, (b) 91%, (c) 96%, (d) 76%, respectively, lower than the value of (e)culvert. ii) However, considering that non-excavation culvert can be installed at a spacing of 5m with the installation cost of the existing excavation culvert at the interval of 10m, it was analyzed that unit subsurface discharge(q) of (a)20.2mm/day(110%), (b)32.8(178%), (c)34.6(188%) (d)27.5(149%) in the four types of non-excavation culvert installed at intervals of 5m under the condition of $ k=10^{-4}cm/s$ was much larger than the amount of (e)type 18.5(100%), existing excavation culvert installed at 10m interval. iii) Through the test construction, peak subsurface drainage discharge($q_p$) was 38.4mm/day, which is larger than the value of design criteria and confirmed that it satisfies the analysis results as well. iv) In particular, it was evaluated that (b)perforated pipe+horizontal mat(B50cm) are low cost, high efficiency subsurface drainage culvert type with sufficient drainage performance(178%).

• Korean Journal of Agricultural Science
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• v.47 no.2
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• pp.263-273
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• 2020

With the change of the agricultural environment (increased rice production, decreased rice consumption, and rice production policies), converting paddy fields into upland fields is an increasing trend. In terms of conversion into upland fields, subsurface drainage is one of the most important factors for good field crop growth. This study evaluates the performance of a subsurface drainage culvert system in paddy fields and reclaimed lands. The obtained results are briefly summarized as follows: 1) After a comparative evaluation of several subsurface drainage culvert systems, including excavated subsurface drainage and non-excavated subsurface drainage types, type 3 (non-excavated, perforated drain pipe 50 mm, filter mat B50 cm, subsoiling 70 cm and culvert spacing 5 m) shows relatively high values among four types in terms of effectiveness (subsurface discharge capability) and economic efficiency (construction cost). 2) Type 3 has proven that it is suitable for design standards of discharge capacity through field tests performed in paddy fields (three sites: Gong-geom, Gae-san, Juk-san) and reclaimed lands (two sites: Gum-ho, Mi-am). 3) In the experiment of Sesamum indicum growth according to the existence of a drainage system, Sesamum indicum growth with a subsurface drainage culvert system had good value in terms of plant shoot and root length, shoot fresh and dry weight, and root fresh and dry weight).

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.4
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• pp.301-306
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• 2008

This experiment was conducted to compare the agronomic characteristics, productivity of silage com and barley cropping, forage sorghum and barley cropping in accordance with Drainage Culvert Spacing at poorly drained paddy field in National Institute of Animal Science, at Seonghwan in Korea, March 2006 to May 2007. The emergency and flowering date were no different among treatments. Emergency rate and flowering date were 90% and July 26 in silage com, 91% and July 21 in forage sorghum, 92% and April 27 in barley, respectively. Dry matter yield was high in line with 3 m drainage culvert spacing (24,389 kg/ha) > 5 m (23,543 kg/ha) > 7 m (21,527 kg/ha) > 0 m (14,132 kg/ha). In cropping systems, dry matter yield of forage sorghum and barley (22,111 kg/ha) was higher than silage com and barley (19,684 kg/ha). Crude protein and TDN yield were high in line with 3 m (2,365 and 15,394 kg/ha) > 5 m (2,255 and 14,513 kg/ha) > 7 m (1,884 and 13,747 kg/ha) > 0 m (995 and 8,682 kg/ha). In cropping systems, crude protein and TDN (total digestible nutrients) yield of forage sorghum and barley cropping system (2,165 and 13,582 kg/ha) was higher than silage com and barley cropping system (1,576 kg/ha and 12,482 kg/ha), respectively. Consequently proper drainage culvert Spacing at poorly drained paddy field was 5 m with forage sorghum and barley cropping system.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.731-736
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• 2001

In this thesis, the study on controlling of cracks of concrete box culvert in early ages is presented. The optimum construction method and economical analysis were proposed also through the experiment of the material and field test. As a result of the experiment of the material, using fly ash, CSA expansive agent and BELITE cement(type IV) showed good result in the control of cracks induced by heat of hydration and shrinkage. As a result of construction test analysis, the maintenance time of form system did not show a big difference in controlling of cracks. Control of distribution of reinforcement, spacing of expansion joint and use of BELITE cement showed big differences in the control of cracks in early ages. As a result of economical analysis, control of construction variables before construction can make it possible to reduce the repair expense.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.167-174
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• 2011

This research was conducted to propose the design methodologies of post-tensioned concrete pavements (PTCPs) for specialized section pavements. The specialized sections considered in this study included bus stop sections in urban bus-only lanes and culvert existing highway sections that often showed severe failures. The PTCP designs of those specialized sections were performed based on both the stresses and the fatigue failures, and more conservative design results were selected. In the stress based design, the maximum tensile stress under extreme load conditions was obtained using finite element analyses first. Then, the number of tendons and the tendon spacing were determined so that the tensile stress was less than the allowable flexural strength. The AASHTO fatigue failure equations were used in the fatigue failure based design. From this study, the design methodologies of PTCP for bus stop sections in bus-only lanes and culvert existing highway sections were successfully suggested.

• Journal of Korea Water Resources Association
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• v.45 no.4
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• pp.419-430
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• 2012

Due to the calculation difficulty on the hydraulic and hydrologic analysis for road drainage facilities design, these analysis techniques are not applicable. This study's result are development of minutely rainfall-intensity equation suitable for road drainage area, verification of rainfall-runoff model joining kinematic wave theory for road drainage area, computational model based GUI for road surface drainage facilities spacing and culvert's size decision and various road drainage channel design. Applicable test on the developed model is proceed, result that in case of road surface dranage facilities spacing is narrower 6~65% than present spacing calculation method, in other case of road cross dranage facilities size is bigger 6~140% than present size decision method.