• Title/Summary/Keyword: Partial drainage characteristics

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Partial Drainage Characteristics of Clayey Silt with Low Plasticity from the West Coast (서해안 저소성 점토질 실트 지반의 부분배수 특성)

  • Kim, Seok-Jo;Lee, Sang-Duk;Kim, Ju-Hyun
    • Journal of the Korean Geotechnical Society
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    • v.32 no.9
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    • pp.17-27
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    • 2016
  • Parial drainage characteristics of clayey silt with low plasticity from the west coast (Incheon and Hwaseong) was analyzed using CPTU based existing correlation equations and compulsory replacement method. Generally, the estimated $OCRs={\kappa}{\cdot}((q_t-{\sigma}_{vo})/{\sigma}^{\prime}_{vo})$ using Powell and Quartman(1988) were higher than those obtained by the oeodometer tests. These trends were noticeable for the layers containing a lot of silty and sand soils. The assessment of partial drainage conditions was performed through Schnaid et al. (2004)'s equation; it is based on plotting the normalized cone resistance, $Q_t$ versus the pore pressure parameter, $B_q$ in combination with the strength incremental ratio, $s_u/{\sigma}^{\prime}_{vo}$ to the CPTU data. It is evident that more than half of the data fall in the range where $B_q$ < 0.3, corresponding to the domain in which the partial drainage prevails when testing normally consolidated soils at a standard rate of penetration (2 cm/s). To estimate the replacement depth of clayey silt with low plasticity, back analysis was carried out to evaluate the internal friction angle based on where the design depths are equal to the checked depths using bearing capacity equation. The internal friction angels obtained from the back analysis tended to increase as the plasticity index decreases, which is ranged approximately from ${\varphi}^{\prime}=2^{\circ}$ to ${\varphi}^{\prime}=7^{\circ}$.

Infiltration and Drainage Capacity of Unsaturated Soil-Aggregate Foundation System (조립질 지반재료로 이루어진 기초의 불포화 침투 및 배수성능 평가)

  • Sung, Yeoul-Jung;Park, Seong-Wan;Tae, Doo-Hyung
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.966-972
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    • 2009
  • Soil-aggregate system in pavement foundations exist in unsaturated conditions. However, change in water content on foundation layers due to joint and structural cracks during rainfall may cause problems like layer deformations or partial settlements. Therefore, a need exist to evaluate the infiltration and drainage capacity of soil-aggregate foundation system under both saturated and unsaturated conditions. To do that, a laboratory soil-water characteristic curve and permeability under unsaturated conditions are assessed to establish hydraulic properties of geomaterials and limited numerical analysis are performed respectively. As a result, it was found that suction profiles and drainage process was greatly influenced by the initial suction of soil-aggregate system at the time of infiltration, soil water characteristics curves, and hysteresis effects.

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Numerical analysis of Self-Boring Pressuremeter test results using FEM - Consolidation characteristics of clay (유한요소해석을 이용한 SBP 시험의 결과해석 - 점성토 지반의 압밀특성)

  • 장인성;정충기
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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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.

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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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A Rathke's Cleft Cyst Presenting with Apoplexy

  • Kim, Ealmaan
    • Journal of Korean Neurosurgical Society
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    • v.52 no.4
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    • pp.404-406
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    • 2012
  • The occurrence of symptomatic pituitary hemorrhage into a Rathke's cleft cyst (RCC) is extremely rare. The author reports an interesting case of intra- and suprasellar RCC presented with features of pituitary apoplexy. This 62-year-old woman suffered acute headache, mental confusion, and partial hypopituitarism. The characteristics of the magnetic resonance imaging seemed most compatible with a hemorrhagic pituitary adenoma. Transsphenoidal drainage of the cyst contents confirmed the diagnosis of hemorrhagic RCC and resolved the symptoms. All published data on this rare clinical entity are extracted and reviewed.

Characteristics of adhesion areas between the tissue expander and capsule in implant-based breast reconstruction

  • Lim, Yoon Min;Park, Kwang Hyun;Lee, Dong Won;Lew, Dae Hyun;Roh, Tai Suk;Song, Seung Yong
    • Archives of Plastic Surgery
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    • v.46 no.4
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    • pp.330-335
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    • 2019
  • Background The use of anatomic implants has improved the aesthetic results of breast surgery; however, implant malrotation is an uncommon, but serious complication of these procedures. Nevertheless, little research has explored implant adhesion. In this study, we investigated adhesion between the expander and the capsule. Methods Seventy-nine cases of immediate breast reconstruction via two-stage implant-based reconstruction performed between September 2016 and November 2017 were evaluated. Mentor CPX4 expanders were used in 14 breasts, and Natrelle expanders in 65. We analyzed areas of adhesion on the surfaces of the tissue expanders when they were exchanged with permanent implants. We investigated whether adhesions occurred on the cephalic, caudal, anterior, and/or posterior surfaces of the expanders. Results Total adhesion occurred in 18 cases, non-adhesion in 15 cases, and partial adhesion in 46 cases. Of the non-adhesion cases, 80% (n=12) were with Mentor CPX4 expanders, while 94.4% (n=17) of the total adhesion cases were with Natrelle expanders. Of the partial adhesion cases, 90.7% involved the anterior-cephalic surface. The type of tissue expander showed a statistically significant relationship with the number of attachments in both univariate and multivariate logistic regression analyses (P<0.001) and with total drainage only in the univariate analysis (P=0.015). Conclusions We sought to identify the location(s) of adhesion after tissue expander insertion. The texture of the implant was a significant predictor of the success of adhesion, and partial adhesion was common. The anterior-cephalic surface showed the highest adhesion rate. Nevertheless, partial adhesion suffices to prevent unwanted rotation of the expander.

Closure of Myelomeningocele Defects Using a Limberg Flap or Direct Repair

  • Shim, Jung-Hwan;Hwang, Na-Hyun;Yoon, Eul-Sik;Dhong, Eun-Sang;Kim, Deok-Woo;Kim, Sang-Dae
    • Archives of Plastic Surgery
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    • v.43 no.1
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    • pp.26-31
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    • 2016
  • Background The global prevalence of myelomeningocele has been reported to be 0.8-1 per 1,000 live births. Early closure of the defect is considered to be the standard of care. Various surgical methods have been reported, such as primary skin closure, local skin flaps, musculocutaneous flaps, and skin grafts. The aim of this study was to describe the clinical characteristics of myelomeningocele defects and present the surgical outcomes of recent cases of myelomeningocele at our institution. Methods Patients who underwent surgical closure of myelomeningocele at our institution from January 2004 to December 2013 were included in this study. A retrospective chart review of their medical records was performed, and comorbidities, defect size, location, surgical procedures, complications, and the final results were analyzed. Results A total of 14 patients underwent surgical closure for myelomeningocele defects. Twelve cases were closed with direct skin repair, while two cases required local skin flaps to cover the skin defects. Three cases of infection occurred, requiring incision and either drainage or removal of allogenic materials. One case of partial flap necrosis occurred, requiring secondary revision using a rotational flap and a full-thickness skin graft. Despite these complications, all wounds eventually healed completely. Conclusions Most myelomeningocele defects can be managed by direct skin repair alone. In cases of large defects, in which direct repair is not possible, local flaps may be used to cover the defect. Complications such as wound dehiscence and partial flap necrosis occurred in this study; however, all such complications were successfully managed with simple ancillary procedures.

Limberg flap reconstruction for sacrococcygeal pilonidal sinus disease with and without acute abscess: Our experience and a review of the literature

  • Sinnott, Catherine J.;Glickman, Laurence T.
    • Archives of Plastic Surgery
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    • v.46 no.3
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    • pp.235-240
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    • 2019
  • Background The efficacy of Limberg flap reconstruction for pilonidal sinus with acute abscess remains unclear. This study aimed to compare outcomes after Limberg flap reconstruction for pilonidal sinus disease with and without acute abscess. A secondary objective was to perform a review of the literature on the topic. Methods A retrospective chart review was conducted of all patients who underwent excision and Limberg flap reconstruction for pilonidal sinus from 2009 to 2018. Patient demographics, wound characteristics, and complication rates were reviewed and analyzed. Results Group 1 comprised 19 patients who underwent Limberg flap reconstruction for pilonidal sinus disease without acute abscess and group 2 comprised four patients who underwent reconstruction for pilonidal sinus disease with acute abscess. The average defect size after excision was larger in group 2 than group 1 ($107.7{\pm}60.3cm^2$ vs. $61.4{\pm}33.8cm^2$, respectively). There were no recurrences, seromas or cases of flap necrosis postoperatively. There was only one revision surgery needed for evacuation of a postoperative hematoma in group 1. There were comparable rates of partial wound dehiscence treated by local wound care, hematoma, need for revision surgery and minor infection between group 1 and group 2. Conclusions Limberg flap reconstruction for pilonidal sinus in the setting of acute abscess is a viable option with outcomes comparable to that for disease without acute abscess. This practice will avoid the pain and cost associated with a prolonged local wound care regimen involved in drainage of the abscess prior to flap reconstruction.

A Case of Scimitar Syndrome (Adult Form) (성인형 Scimitar 증후군 1예)

  • Kim, Woo-Gyu;Kim, Jeong-Kyung;Jeon, Seong-Hee;Lim, Dal-Soo;Min, Cheol-Hong;Park, Hun-Sik;Lim, Byung-Sung;Hong, Suk-Keun;Hwang, Hweung-Kon;Kim, Mi-Young
    • Tuberculosis and Respiratory Diseases
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    • v.47 no.2
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    • pp.259-264
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    • 1999
  • The scimitar syndrome, a rare complex anomaly, is defined as an anomalous right pulmonary venous drainage, partial or complete, to the inferior vena cava. The shape of the Turkish curved sword (scimitar) has provided the name of this syndrome. Additional characteristics of this syndrome such as hypoplasia of the right lung and of the right pulmonary arterial tree, anomalous arterial supply of the right lung from the aorta, dextrocardia and bronchial anomalies are common. Recently we experienced a case of scimitar syndrome (adult form) in a 19-year-old woman patient, so we report the case with a brief review of the literature.

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Determination of Consolidation Characteristics of Clayey Soils from the Self-boring Pressuremeter Test (자가굴착식 프레셔미터 시험을 이용한 점성토의 압밀특성 산정)

  • 장인성;정충기;김명모;조성민
    • Journal of the Korean Geotechnical Society
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    • v.18 no.2
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    • pp.87-96
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    • 2002
  • The strain holding test(SHT) or the sell-boring pressuremeter test(SBPT) has been effectively utilized to determine the horizontal coefficient of consolidation$(c_h)$ of clayey soils. However, a commonly used procedure proposed by Clarke et al.(1979) can lead to an erroneous estimation of $(c_h)$ because of its simplified assumptions. This paper deals with numerical analyses based on realistic test conditions of the generally accepted testing procedure, and .using the most commonly used type of pressuremeter. The effects of pressuremeter geometry, partial drainage during cavity expansion, and the cavity strain level for the holding test are investigated with the radial distributions of the initial excess pore pressure and their dissipation rate. Based on the results of the numerical analyses, the curve of the time factor for the 50% degree of consolidation($T_{50}$) needed to estimate $(c_h)$ is proposed. Comparisons are made between $(c_h)$ values estimated from the SHT or the SBPT and those obtained from other in situ and laboratory tests performed at two sites in Korea. These results suggest the improved capability of the $T_{50}$ curve proposed herein.