• Journal of Korea Water Resources Association
• /
• v.52 no.4
• /
• pp.301-312
• /
• 2019

The importance of the dual drainage system model has increased as the urban flood damage has increased due to the increase of local storm due to climate change. The dual drainage model is a model for more accurately expressing the phenomena of surface flow and conduit flow. Surface runoff and pipe runoff are analyzed through the respective equations and parameters. And the results are expressed visually in various ways. Therefore, inundation analysis results of dual drainage model are used as important data for urban flood prevention plan. In this study, the applicability of the COBRA model, which can be interpreted by combining the dual drainage system with the natural watershed and the urban watershed, was investigated. And the results were compared with other dual drainage models (XP-SWMM, UFAM) to determine suitability of the results. For the same watershed, the XP-SWMM simulates the flooding characteristics of 3 types of dual drainage system model and the internal flooding characteristics due to the lack of capacity of the conduit. UFAM showed the lowest inundation analysis results compared with the other models according to characteristics of consideration of street inlet. COBRA showed the general result that the flooded area and the maximum flooding depth are proportional to the increase in rainfall. It is considered that the COBRA model is good in terms of the stability of the model considering the characteristics of the model to simulate the effective rainfall according to the soil conditions and the realistic appearance of the flooding due to the surface reservoir.

• 한국관개배수회지
• /
• no.13
• /
• pp.3-6
• /
• 1996

• Proceedings of the Korea Water Resources Association Conference
• /
• 2015.05a
• /
• pp.362-366
• /
• 2015

지난 백여 년 동안 인간은 과거의 그 어떤 선조들도 이루지 못한 지식과 기술의 발전을 통해 고도로 산업화된 사회를 이루었지만, 전 지구적으로 기후변화라는 부차적인 결과와 현실에 직면하고 있다. 이상기후 현상은 전지구 규모뿐만 아니라 일정한 소규모 지역에서도 관측되고 있으며, 국내에서는 특히 특정 지역에 국한되어 단시간에 발생하는 집중호우가 대표적인 사례이다. 현재까지 집중호우 발생 지역과 정도를 예측하기란 불가능한 상태이며, 산업화와 도시화가 진행될수록 그 피해는 더욱 증가할 것으로 예상된다. 따라서 집중호우에 대비한 도시 배수 시스템을 재점검할 필요가 있으며, 기존의 배수시설을 대체할 만큼 효율적인 배수구조물의 개발이 시급하다. 기존 도시지역의 측구형 수로관에는 마감불량, 정밀시공의 어려움, 이물질의 누적과 물고임, 노출로 인한 파손, 포장층 침투수 배수문제 등 많은 문제점들이 존재한다. 따라서 본 연구에서는 기존의 측구형 수로관의 단점을 보완하는 더욱 효율적인 집수정을 개발하고자 하였다. 집수정을 덮고 있는 포장층 상부면을 따라 흐르는 표면수를 처리할 뿐만 아니라, 포장층 내부로 스며드는 침투수를 처리 가능하도록 구조체 상부에 침투수 유입공을 설치하여, 표면수와 침투수를 동시에 고려하는 이중배수 시스템을 구성하였다. 본 연구에서 개발하는 집수정 구조체는 침투수에 의한 도로 및 구조체의 내구성 감소 및 겨울철 동파 현상을 방지할 수 있을 뿐 아니라, 단순공정, 시공성 향상, 유지비용절감 등 기존 배수 시스템과 비교해 많은 장점을 내포하고 있다. 본 연구에서 개발하는 이중배수 집수정의 효율 및 배수능력 평가를 위해서는 기존의 구조체와 차별되는 침투수 유입공에 대한 평가가 선행되어야 한다. 이를 위해서 침투수 유입공에 대한 실내 실험 장치를 구축하였으며, 반복 실험을 통해 침투수 유입공을 통한 배출 능력을 평가하고자 하였다. 또한 실험 결과를 바탕으로 구조체의 효능을 결정짓는 기준을 제시하고자 한다.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.11 no.3
• /
• pp.243-254
• /
• 2009

Tunnel problems relate to pore water pressure generally occur due to the restriction of groundwater flow into the tunnel which is generally caused by the deterioration of drainage systems. Previous studies have identified the problem as combined mechanical and hydraulic interaction occasions. In this study, detrimental effects of pore water pressure on the lining were investigated using the finite element method considering deterioration of the drainage system. Particularly, double-lined linings with drain-holes are considered. Deterioration of drainage system is represented as blockages of drain-holes. It is identified that the secondary lining ran be influenced by the deterioration of drainage system. It is shown that a tunnel with all drain-holes blocked moved upward, and unbalanced drain-hole blocking may result in torsional behavior of the tunnel which causes significant damages to the secondary linings.

• Journal of the Korean Geotechnical Society
• /
• v.19 no.5
• /
• pp.243-252
• /
• 2003

Environmental Double Pile method was presented as a device to improve low permeable contaminated soil. EDP is one of the latest technology in a concept of one step process that is applied to low permeable contaminated ground to reutilize the site by enhancing drainage, contaminated remediation, bearing capacity of piles. In order to evaluate on-site applicability of this technology, qualities of EDP's drainage, strength and remediation were assessed through a series of experiments; EDP was verified to achieve remediation and improvement of soft ground.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.12
• /
• pp.1273-1279
• /
• 2013

We propose a dual grating alignment technique for roll-to-roll positioning which allows achieving nanometer scale alignment by using micro-size marks. The high precision alignment system were designed and manufactured. It was confirmed that the optical system was properly adjusted and fully aligned with the dual gratings. The experiment and computer simulation results were presented. Alignment accuracy below 50 nm was achieved.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.17 no.4
• /
• pp.40-51
• /
• 2014

This study aims to investigate urban inundation considering building footprints based on dual-drainage scheme. For this purpose, LiDAR data is cultivated to generate two original data set in terms of DEM with $1{\times}1$ meter and building layer of the study drainage area in Seoul and then the building layer is overlapped as vector polygon with the mesh data with the same size as DEM. Then, terrain data for modeling were re-sampled to reduce resolution as $10{\times}10$ meters. As results, the simulated depth without considering building footprints has a tendency to underestimate the inundation depth compared to observed data analized by CCTV imagery. Otherwise, the simulation result considering building footprints revealed definitely higher fitness. The difference of inundation depth came from the variation of inundation volume which was relevant to inundation extent. If the building footprints are enlarged, the possible inundation depth is increased, which results in being inundation depth higher because hydrological conditions such as rainfall depth are conservational. Otherwise, according to comparison of inundation extents, there were no significant difference but the case of considering building footprint was revealed slightly higher fitness. Thus, it is concluded that the considering building footprint for inundation analysis of urban watershed should be required to improve simulation accuracy synthetically.

• Journal of the Korean Geotechnical Society
• /
• v.25 no.8
• /
• pp.33-45
• /
• 2009

The conventional single-core PBDs have been widely used in order to accelerate consolidation settlement of soft grounds. When using the single-core PBD in a thick clay deposit, a delay of consolidation may occur due to high confining pressure in the thick deposit and necking of drains. This study is to compare the performances of soil improvement by the single-core and double-core PBD installed at a site in Busan New Port which exhibits approximately a 40m-thick clay layer. An in-situ test program was performed at the test site where a set of the double-core PBDs and single-core PBDs were installed to compare the efficiency of each drain. In addition, the discharge capacity of each PBD has been measured using the modified Delft Test. A series of laboratory tests for estimating in-situ soil properties have also been performed in order to obtain input parameters for a numerical program ILLICON. The discharge capacity of the double-core PBD is higher than that of the single-core PBD in the modified Delft Test. However it is observed from the comparative in-situ test and numerical analysis that there is no difference in the performance of ground improvement between the two drain systems. This discrepancy comes from the fact that the amount of water released during consolidation in most common field conditions is much smaller than the capacity of even the single core PBD. And thus, considering actual field conditions, it can be concluded that the single-core PBD has enough discharge capacity even in the thick clay deposit such as this test site.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.5
• /
• pp.869-886
• /
• 2018

Rockbolt is one of the most common supports used to reinforce discontinuous rock during underground excavation. Extra drain pipes are installed to improve excavation workability and the anchorage of rockbolts in water bearing ground. The drain pipe is effective in improving the workability by providing drainage path, but it is difficult to expect the reinforcement effect, increasing disturbance of the discontinuous rock mass and the construction cost. To solve this problem, dual purpose rockbolt (DPR) has been developed for the reinforcement of rock and the drainage of ground water. DPR was able to improve the mechanical and hydraulic stability of the rocks quickly and economically. Two kinds of DPRs using FRP (Fiber Reinforced Plastic) and steel were investigated for the mechanical and hydraulic performance. Also, the workability and stability of DPR were analyzed.

• Journal of the Society of Disaster Information
• /
• v.13 no.4
• /
• pp.483-490
• /
• 2017

Recently, the demand for industrial and residental land are increasing with economic growth, but it is difficult to obtain the area for development with good ground condition. Various kinds of vertical drain technologies such as sand drain, sand compaction pile, packed drain, PVD are commercially available to improve the soft ground. Discharge capacity is the important factor of vertical drains. However, under field conditions, discharge capacity is changed with various reasons, such as soil condition, overburden pressure, and so on. In this paper, the experimental study was carried out to estimate the discharge capacity of four different types of PBD, PBD for double core PBD, deep type PBD, X type PBD, general type PBD. Characteristics of the discharge capacity for the surcharge load and hydraulic gradient were analysed. The double core PBD was excellent for discharge capacity in this study.