• Title/Summary/Keyword: Pressure drainage

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A study on efficient management of the drainages of underground tunnels for environmentally friendly urban railway systems (도시철도 친환경 지하터널 배수형식의 효율적인 유지관리 방안 검토)

  • Baek, Jong-Myeong;Hong, Jong-Hun;Kim, Han-Bae
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.1982-1990
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    • 2010
  • Excepting tunnel of dorimstream - ccachimountain station section, the subway line No.2th section was build using ASSM and NATM methods because of soil pressure and land condition. The way of dealing underground water was selected without sufficient preconsideration of geographical features, ground condition, influence of lowing underground water, and long-term cost of running maintenance so that the form of undrained tunnel was build having decreased construction characteristics and technically improper elements. The form of partial drainage is very difficult to manage structures of tunnel, because water leakage, water pressure causing cracks of lining concretes and scaling are constantly happened. so partial drainage suggest that setting reinforced Anchor Bolt to prevent buoyancy and should increase center drainage way up to height of railroad. Partial drainage suggest that holey pipe(${\phi}$350mm) manhole, drainage checking pipe manhole are should be regularly dredged, when changing roadbed(gravel${\rightarrow}$concrete) drainage checking pipe manhole should be build and setting a limitation of entering underground water's quantities. Beside drainage degree in changed section of structures causing instability of structures is continuous degree. so if efficient drainage way and the patterns of flaws, problems are considered in survey, it will be expected to have a advantage condition in maintenance part.

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Development of Nursing Practice Guideline for External Ventricular Drainage by Adaptation Process (수용개작을 통한 뇌실외배액 간호 실무지침 개발)

  • Jung, Won Kyung;Yi, Young Hee
    • Journal of Korean Clinical Nursing Research
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    • v.22 no.3
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    • pp.294-304
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    • 2016
  • Purpose: This study was done to develop an evidence-based external ventricular drainage (EVD) nursing practice guideline in order to provide standardized nursing and prevent EVD related complications. Methods: We used the standardized methodology for nursing practice guideline adaptation developed by Korean Hospital Nurses Association for the guideline adaptation process in this study. Results: The newly developed EVD nursing practice guideline was adapted to the American Association of Neuroscience Nurses (AANN)'s clinical practice guideline which is 'Care of the patient undergoing intra-cranial pressure monitoring/external ventricular drainage of lumbar drainage.' There were 61 recommendations documented in the preliminary guideline all evaluated by 9 experts based on acceptability and applicability. The final practice guideline was composed of 3 domains with 57 recommendations. The three domains of nursing were the insertion, maintenance, and removal of the EVD. The number of recommendations in each domain was 8 in EVD insertions, 39 in EVD maintenance, and 10 in EVD removals. Of the 57 recommendations 3.5% were level 1, 31.5% were level 2, and 65% were level 3. Conclusion: The standardized practice guideline can improve nurses' performance and accuracy. It can also be used as the foundation for effective communication between all medical staff.

Subjective Evaluation of Drainage Noise in Bathroom of Apartment Buildings (공동주택 욕실 배수소음의 주관적 평가)

  • 장호연;류종관;전진용
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.766-771
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    • 2003
  • In this study the drainage noises were investigated for the subjective allowing limitation and the testified classes. 7 point scale was selected to evaluate the annoyance level with vocabularies. As a result, 'a little annoying' is the most suitable expression for the allowing limitation, and the sound pressure levels for the urinal was 43.5㏈ and the bathtub was 44.6㏈.

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Finite Element Analysis based on the Macroelement Method for the Design of Vacuum Consolidation (진공압밀공법 설계를 위한 Macro-element법 기반 유한요소해석)

  • Kim, Hayoung;Kim, Kyu-Sun
    • Journal of the Korean Geotechnical Society
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    • v.38 no.8
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    • pp.29-37
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    • 2022
  • A three-dimensional analysis is required to interpret the drainage behavior of an improved ground with vertical drains, and the macroelement method enables efficient interpretation considering the three-dimensional drainage effect of vertical drains under two-dimensional plane strain condition. In this study, a novel finite element analysis program was developed by applying the macroelement method to the vacuum consolidation method used in ground improvement practice. The conventional macroelement method was used to calculate the amount of drainage from the vertical drain by setting the excess porewater pressure in the drainage material to zero; however, the program developed in this study was improved to consider negative excess porewater pressure as an actual vacuum consolidation condition. To verify the performance of the program, because of a comparison with the measurement values at the site where the vacuum consolidation method was applied, results predicted by the program and field measurement data showed similar settlement behavior.

Hydraulic and structural interaction of a double-lined tunnel lining due to drainhole blockings (이중구조 라이닝의 배수공 막힘에 따른 수리-역학적 상호작용)

  • Shin, Jong-Ho;Nam, Taek-Soo;Chae, Sung-Eun;Yoon, Jae-Ung
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.11 no.3
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    • pp.243-254
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    • 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.

Comparison between Soil Drainage Experiment and Finite Element Analysis for Air Diffusion in Multiphase Porous Media (다공성 매질내의 공기압 확산에 대한 실내 배수시험과 유한요소해석 비교분석)

  • Kim, You-Seong;Kim, Jae-Hong;Kim, Tae-Heon;Lee, Jin-Kwang
    • Journal of the Korean Geotechnical Society
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    • v.30 no.2
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    • pp.77-85
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    • 2014
  • The paper presents comparison between numerical and experimental results to verify finite element algorithm of air diffusion in three-phase porous media. The theory of two-phase flow in partially saturated soil is a fundamental study to predict the safety for $CO_2$ sequestration. Geotechnical engineering problems exposed to atmospheric pressure generally assume that air pressure is equal to zero in three-phase porous media, but the geotechnical engineering problem at a depth of about over 1 km needs to be considered in connection with deformable solid skeleton due to air pressure. Therefore, the objective of this study is to validate the numerical algorithm by comparing with results obtained from measurement of air diffusion and dissipation through drainage test.

The Role of Negative-Pressure Wound Therapy in Latissimus Dorsi Flap Donor Site Seroma Prevention: A Cohort Study

  • Angspatt, Apichai;Laopiyasakul, Thana;Pungrasmi, Pornthep;Suwajo, Poonpissamai
    • Archives of Plastic Surgery
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    • v.44 no.4
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    • pp.308-312
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    • 2017
  • Background Donor site seroma is the most common complication after latissimus dorsi (LD) flap harvest. This study aimed to evaluate the efficacy of negative-pressure wound therapy (NPWT) in preventing donor site seroma formation after the harvest of an LD flap for breast reconstruction. Methods In this prospective matched-pair study, 40 patients in whom an LD flap was harvested for breast reconstruction were enrolled. NPWT was used in 20 patients, and in a control group composed of another 20 patients, the conventional donor site dressing technique was used. Information was collected regarding postoperative complications, the incidence of seroma, total drainage volume, the number of percutaneous seroma aspirations, and the volume aspirated. Results In the NPWT group, the incidence of seroma formation after drain removal was significantly lower than in the control group (15% vs. 70%; odds ratio=0.07; relative risk, 0.24). Both the mean percutaneous aspirated volume (P =0.004) and the number of percutaneous aspirations (P=0.001) were also significantly lower in the NPWT group. There were no significant differences in the total drainage volume or the duration of wound drainage between the NPWT dressing group and the control group (P>0.05). Conclusions This study showed that NPWT is a promising tool for reducing the incidence of seroma formation after removing the drain at the donor site after LD flap harvesting. It is a simple and safe technique.

A Study on the Soft Ground Improvement in Deep Depth by Application of PBD Method Using Model Test (실내모형실험을 통한 PBD공법이 적용된 대심도 연약지반 개량에 관한 연구)

  • Byun, Yoseph;Ahn, Byungje;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.6
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    • pp.69-77
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    • 2009
  • The shortage of bearing capacity and settlement, shear deformation may occur when constructing a structure such as harbor, airport and bridge on soft ground such as marine clay, silty clay, sandy soil because it is very soft. The various ground improvement methods were applied to obtain preceding settlement of soft ground and strength increase. The vertical drain method has been used to reduce the required time for consolidation of the soft ground. Especially, the PBD (Plastic Board Drain) has been widely used among in the vertical drain method. In this study, a behavior of characteristic was evaluated by operating a compound drainage capacity test about the PBD (Plastic Board Drain) method applied in soft clay in deep depth. As a result, the settlement gradually occurred with increase of surface load. The consolidation settlement was processed with dissipation of pore pressure after surface load of $500kN/m^2$. Accordingly, it was found that change of settlement through load steps was resulted from dissipation of pore pressure. It was also found that the drainage capacity of vertical drains was considerably reduced with pressure increase and time elapse.

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Epidural Hematomas due to Occipital Artery Injury Following Ventriculoperitoneal Shunt and Extraventricular Drainage

  • Choi, Jeong-Hoon;Moon, Jae-Gon;Hwang, Do-Yun;Choi, Jong-Hun
    • Journal of Korean Neurosurgical Society
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    • v.41 no.5
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    • pp.314-317
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    • 2007
  • Ventriculoperitoneal [VP] shunt is a common treatment for hydrocephalic patients. However, complications, such as shunt tube occlusion, infection, intracranial hemorrhage, seizure can occur. Of these, intracranial hemorrhage may occur due to intracranial vascular injury or a rapid decrease of intracranial pressure [ICP]. Most of these hemorrhages are subdural hematomas [SDH] while a few are epidural hematomas [EDH]. It is extremely rare for an intracranial hemorrhage to occur due to an extension of the bleeding from an injured extracranial vessel. We report two cases of EDH due to occipital artery injury following VP shunt and extraventricular drainage [EVD].

Design and Construction of Bottom Drainage Tunnel and the Watertight Tunnel (배수형 터널과 방수형 터널의 설계와 시공)

  • Kim, Seung-Ryeol;Park, Gwang-Jun;Park, Bong-Gi
    • Proceedings of the Korean Geotechical Society Conference
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    • 1993.03a
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    • pp.49-58
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    • 1993
  • Reappraisal of the design and the construction concept of the bottom drainage tunnel has been made through the seepage analysis. An appropriate design approach for this tunnel has also been proposed. It was revealed from this study that water pressures acting on the concrete lining in the bottom dralnage tunnel much depend on the permeability of the surrounding ground, the source of water supply and the discharge capacity of dralnage facilities. The full release of these water pressures by the current drainage system could not be expected if this type of tunnel is constructed in the ground including alluvial deposits having a high permeability. The necessity of a proper reinforcement of the concrete lining or a modification of its shapes corresponding to the water pressure has been suggested.

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