• 한국터널지하공간학회 논문집
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• 제18권1호
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• pp.31-40
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• 2016

본 연구에서는 철도터널의 배수재로 사용되는 부직포의 배수 특성을 정밀하게 조사하기 위하여 실제 터널 시공현장과 유사한 경계조건 및 하중조합을 가진 실험장비를 고안하였다. ASTM D4716과 유사한 성능을 갖는 실험장비는 숏크리트 및 방 배수재와 콘크리트 경계면의 굴곡을 현장 조건과 유사하게 구현할 수 있으며 관련 시방조건 만족유무에 따른 실험결과로부터 일반 배수재의 성능을 규명하였다. 또한 배수성능 개선을 위하여 부직포 사이에 지오그리드를 삽입한 혼합형 배수재를 사용한 경우와 일반 배수재에 대한 실험결과로부터 혼합형 배수재의 배수성능 및 적용방안에 대하여 고찰하였다.

• 한국안전학회지
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• 제33권4호
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• pp.119-126
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• 2018

In recent years, as flood damage caused by heavy rains increased, the great-depth tunnel using urban underground space is emerging as a countermeasure of urban inundation. The great-depth tunnel is used to reduce urban inundation by using the underground space. The drainage efficiency of great-depth tunnel depends on the intake design, which leads to increase discharge into the underground space. The spiral intake and the tangential intake are commonly used for the inlet facility. The spiral intake creates a vortex flow along the drop shaft and reduces an energy of the flow by the wall friction. In the tangential intake, flow simply falls down into the drop shaft, and the design is simple to construct compared to the spiral intake. In the case of the spiral intake, the water level at the drop shaft entrance is risen due to the chocking induced by the flowrate increase. The drainage efficiency of the tangential intake decreases because the flow is not sufficiently accelerated under low flow conditions. Therefore, to compensate disadvantages of the previously suggested intake design, the multi-stage intake was developed which can stably withdraw water even under a low flow rate below the design flow rate. The hydraulic characteristics in the multi-stage intake were analyzed by changing the flow rate to compare the drainage performance according to the intake design. From the measurements, the drainage efficiency was improved in both the low and high flow rate conditions when the multi-stage inlet was employed.

• 대한설비공학회지:설비저널
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• 제25권5호
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• pp.401-411
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• 1996

• 대한토목학회논문집
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• 제31권1D호
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• pp.83-90
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• 2011

도로하부 혹은 성토부를 구성하는 다져진 지반재료들은 불포화상태로 존재하는 관계로 재료의 침투 혹은 배수에 대한 평가시 불포화지반의 특성이 반영하는 것이 필요하다. 이에 본 연구에서는 강우강도와 시간조건에서 도로하부 재료에서 어떠한 영향이 있는지를 파악하고자 수치해석적인 연구를 수행하였다. 기존의 실험을 통해 획득한 불포화 함수특성 자료를 활용하였으며 SWCC를 통하여 투수계수를 추정하였다. 제안된 방법을 통하여 시간 변화에 대한 침투 및 배수성능을 평가하였다. 연구결과 침투 및 배수 과정에서 초기흡수력의 여부와 함수특성곡선의 경로에 따라서 많은 영향을 받고 있음을 알 수 있다.

• 화약ㆍ발파
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• 제39권4호
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• pp.12-21
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• 2021

본 연구에서는 발파진동에 대한 콘크리트 배수관로 보호구의 내진성능을 비교하기 위해 일련의 FEM 수치해석을 수행하였다. 비교 대상은 본 연구에서 제안하는 두 종류의 ㅁ 형태의 보호구와 재래식의 ㄷ 형태의 보호구이다. 해석 과정에서는 폭원 이격거리와 지발당 장약량을 변화시키면서 세 종류의 보호구의 내진 저항을 비교하였다. 그 결과, 본 연구에서 제안하는 두 종류의 보호구가 진동저감 성능의 측면에서 재래식 보호구에 비해 더 우수한 것으로 나타났다.

• 한국산학기술학회논문지
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• 제20권3호
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• pp.513-519
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• 2019

배수 시스템에서 오염퇴적물이 장기간 발생하게 되면 배수관 폐색현상을 일으켜 유지관리가 어렵고 배수관의 잔류수압이 커져 파손의 위험이 있다. 이에 본 연구에서는 PVDF 필름에 의해 발생하는 진동에너지를 활용하여 물리/화학적 폐색에 의한 터널배수 시스템 폐색을 감소시키는 시스템을 구축하였다. 또한, PVDF 필름을 기존 배수재와 융합한 하이브리드 배수재와 역압전 효과를 일으킬 수 있는 구동장치로 배수재 유지관리 시스템을 개발하였다. 터널 배수관 유지관리 성능을 고찰하기 위하여 실내조건에서 오염퇴적물을 모사하고 진동조건에서 폐색저감 효율을 관찰하였다. 그 결과 개발된 PVDF 필름 구동 장비로 20분 내외의 진동에너지를 발생하여 씻겨나간 오염퇴적물의 잔류면적을 측정한 결과 74.62%의 오염퇴적물 제거효과를 볼 수 있었다. 현장 적용성 평가를 위하여 PVDF 필름을 배수관에 부착하고 장기적으로 음압측정을 하여 실내실험으로부터의 측정 음압과 비교하여 현장실험의 대응율을 제시하였다. 현장실험은 터널 배수관으로부터 내부에 폐색이 주로 발생하는 구간인 종배수관과 횡배수관에 PVDF 필름을 부착하였고 터널현장 음압측정 실험으로부터 오염물퇴적 제거효율은 실내실험대비 현장 대응율은 90% 이상으로 확인됐다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 가을 학술발표회 논문집
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• pp.67-74
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• 1999

Self-Boring Pressuremeter Test(SBPT) is known to be the most effective in-situ test method which can reliably determine consolidation characteristics as well as deformation modules and untrained shear strength. In order to derive the coefficient of consolidation using SBPT results it is necessary to obtain the dissipation behavior from the pore pressure change with time during constant radial strain(generally 10%) and to derive the reliable time factor(Τ) from the analytical method which considers the real in-situ conditions. As previous studies on time factor are based on the assumptions of plane strain condition that the membrane of SBP is infinite, of untrained condition during the expansion of the probe and of elastic soil behavior during consolidation, these analyses can't consider the real boundary conditions and the real soil behaviour. In this study, consolidation analysis similar to real in-situ conditions including test procedure is conducted using finite element program which employs MCC model and Biot theory. Time factor considering the effects of finite membrane length, the total pressure change during consolidation and partial drainage is proposed and compared with previous results.

• Geomechanics and Engineering
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• 제19권5호
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• pp.435-445
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• 2019

A series of element tests with different drainage conditions and strain rates were performed on compacted unsaturated non-plastic silt in unconfined conditions. Soil samples were compacted at water contents from dry to wet of optimum with the degree of saturation varying from 24 to 59.5% while maintaining the degree of compaction at 80%. The tests performed were shear infiltration tests in which specimens had constant net confining pressure, pore air pressure was kept drained and constant, just before the shear process pore water pressure was increased (and kept constant afterwards) to decrease matric suction and to start water infiltration. In constant water content tests, specimens had constant net confining pressure, pore air pressure was kept drained and constant whereas pore water pressure was kept undrained. As a result, the matric suction varied with increase in axial strain throughout the shearing process. In both cases, maximum shear strength was obtained for specimens prepared on dry side of optimum moisture content. Moreover, the gradient of stress path was not affected under different strain rates whereas the intercept of failure was changed due to the drainage conditions implied in this study.

• 한국지형학회지
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• 제18권1호
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• pp.1-13
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• 2011

김해시 대동면 일대에는 자연배수를 위한 승수로, 안정적인 용수 확보를 위한 터널 굴착, 야주하천의 인위적 직강화, 일반적인 형태의 양·배수장 등, 범람원에서 볼 수 있는 각종 양·배수시설이 다양하게 나타나고, 이들 시설의 개발, 유지, 운영에는 범람원 지역의 지형 조건이 크게 작용하고 있음을 확인했다. 특히 운하천 유역의 경우, 운하천 취수문만 열면 자연 경사에 의해 얼마든지 낙동강 본류의 물을 양수할 수 있고, 연구지역에서 가장 큰 양수장인 월당양수장에서 낙동강 본류의 물을 직접 양수할 수 있다. 감내천은 한때 운하천(이전 하동천)의 상류였으며, 현재는 덕산승수로를 통해 낙동강으로 배수된다. 따라서 이러한 배수체계는 운하천 저지대의 홍수 피해 및 배수 부담을 덜어주고 있다.

• 한국조경학회지
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• 제33권5호통권112호
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• pp.69-82
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• 2005

These studies were carried out (1) to investigate the growth characteristics of Sedum album L. in the field, (2) to propose a suitable shallow peen roof system for this plant, and (3) to evaluate plant growth in the proposed system over the long term. The growth characteristics, such as morphological properties, growth habit, shade tolerance, and flowering, were surveyed. In experimental shallow green-roof systems, the effects of drainage type, substrate type, and soil depth on plant growth were investigated. Then drought tolerance was investigated. After planting Sedum album L. in the proposed system survival rate, cover, and resistance to insects, heal and cold were evaluated for about 2 years. The results of these studies are summarized below. 1. In the field, the aboveground part of Sedum album L. did not die back during the winter. Plant height was 4$\sim$7 cm. Roots were distributed to a depth of 5$\sim$7 cm. Sedum album L. is a compact ground-cover plant that spreads vigorously. Shading condition of less than $30\%$ of full sunlight didn't cause any trouble, but shading conditions above $87\%$ made the shape of the shoots and leaves abnormal. The plant bloomed from June to August and had a rather large compound umbel of white, star-shaped flowers. 2. Two systems, a drainage-blend-10 cm soil depth and a reservoir$\cdot$drainage-blend-15 cm soil depth, performed best in terms of cover, fresh weight, and dry weight. The first has an advantage for green roofs because it is lighter than the latter. 3. In drainage-blend-10 m soil depth and modified reservoir · drainage-blend-10 cm soil depth system no plants died for about 4 months after stopping the irrigation. The visual quality of the latter system was above 5 for 4 months and that of the former was under 5 after 2 months. In the field, however, the drought tolerance of Sedum album L. grown in the former would be enough to withstand the dry season. Considering the urban ecosystem and the importance of healthy growth the modified reservoir $\cdot$ drainage-blend-10 cm soil depth system was finally recommended. This system was composed of a 4 cm thick drainage layer and drain outlets placed at a height of 2.5 cm. 4. In the proposed system, the survival rate was $100\%$, and there was no injury induced by insects and heat. The leaf density decreased a little in winter. Cover increased throughout the year. Sedum album L. was planted with a cover of 72$cm^{2}$ on 3 April 2003; on 16 June 2003 and 15 June 2004, cover was $132.66\pm$5.87 $cm^{2}$(1.8 times) and $886.98\pm$63.51 $cm^{2}$(12.3 times), respectively.