• Title/Summary/Keyword: Pre-construction

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A New Proposed Technique for a Secondary Consolidation Coefficient Based on the Constant Rate of Strain Test (CRS시험에 의한 2차압밀계수의 결정방법 제안)

  • 김형주;이민선;이용주;김대우
    • Journal of the Korean Geotechnical Society
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    • v.20 no.8
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    • pp.113-121
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    • 2004
  • The present study is suggested to estimate the degree of secondary consolidation caused by various changes of stress such as loading, unloading and reloading in improving poor subsoil through pre-compression loading construction method and, for this purpose, examined the characteristics of the consolidation of Kunsan clay through incremental loading test (IL) using standard consolidation tester and constant loading rate test (CLR), which were adapted from the constant rate of strain test (CRS). In addition, after CRS test, this study determined the characteristics of secondary consolidation and relationships among void ratio, effective stress and time according to the ratio of effective over-consolidation on reloading at the point of time of random expansion. Kunsan clay had larger expansion and smaller secondary consolidation settlement when the ratio of effective over-consolidation was high. In addition, when loading was applied after the load was removed at once, the secondary consolidation coefficient $C'_{\alpha}$ was smaller than that when the load was removed gradually, and when the ratio of effective over-consolidation was over 1.4 a similar value was produced. Based on the entire settlement resulting from reloading, the secondary consolidation coefficient $C"_{\alpha}$ increased non-linearly with the lapse of time but the final value was similar to that in the case of rapid removal. The strain velocity of void ratio was in a regular linear relationship with the increase of loading time regardless of the ratio of effective over-consolidation in both tests and it grew smaller with the increase of the ratio of effective over-consolidation.tion.

A Development of System for Efficient Quantitative Risk Assessment on Natural Gas Supply Facilities (천연가스 공급시설에 대한 효율적 정량적 위험성 평가를 위한 시스템 구축과 적용)

  • Yoon, Ik-Keun;Oh, Shin-Kyu;Seo, Jae-Min;Lim, Dong-Yeon;Yoon, En-Sup
    • Journal of the Korean Institute of Gas
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    • v.16 no.1
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    • pp.39-45
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    • 2012
  • While the natural gas supply industry has continuously been growing, its potential hazard has also risen since the natural gas facilities essentially require installations that carry highly flammable and pressurized gas close to the populated areas, posing a serious consequence of significant property damage as well as human casualties in the event of accident. Therefore Quantitative Risk Assessment (QAR) has been recognized as a appropriate method to reduce the risk as far as possible, considering the reality of unachievable zero-risk. However, it is hard to perform effective QRA on hundreds of gas facilities because of insufficient number of expert and long-term analysis. In this paper, we suggest a conceptual QRA system framework to support more efficient risk analysis in gas supply facilities. In this system, the experts make questionnaires and internal calculation formula needed in accident frequency/consequence analysis of the facility through pre-analysis on the point of analysis, called incident point, and general users locate the point on the map and input the value required by the questionnaire to obtain the risk. Ultimately, this is suggested based on the idea that the specialization is available in QRA analysis process and the validity of the system is verified through actual system construction and application.

A Study to Analyse the Characteristic of New Condominium Buyers with the object of Investment and Owner-Occupation : The Case of Busan and Gyeong Nam Area (공동주택 분양시장의 투자자와 실수요자 특성 연구 - 부산·경남지역을 중심으로 -)

  • Han, Gwang-Ho;Kim, Tae-Yong;Ro, Seung-Han
    • Journal of Cadastre & Land InformatiX
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    • v.47 no.2
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    • pp.91-105
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    • 2017
  • It is important to identify new apartment buyers with the object of investment and owner-occupation because it may determine the scope of marketing and marketing strategies. Establishing an more effective marketing scope and strategies should result in maximizing profits and reducing expenses. In this study, we split the participants in the new apartment market depending on the buyers' intent - investment and owner-occupation - and then examine their characteristics. We employ condominium buyers' information from 2011 to 2016, which is provided by the one of the largest construction companies in South Korea. The sites of the condominium samples locate in Gyeongnam and Busan areas and the number of household sample is 5,549. The results show that investors are approaching at a greater distance than actual buyers. The higher the age and the lower the price, the higher the probability of participation of investors. We also find that the samples of Busan have different results from the others, which may imply that the area has more demand due to its attractiveness.

Study on Diagnosis by Facial Shapes and Signs as a Disease-Prediction Data for a Construction of the Ante-disease Pattern Diagno-Therapeutic System - Focusing on Gallbladder's versus Bladder's Body and Masculine versus Feminine Shape - (미병학(未病學) 체계구축을 위한 질병예측자(疾病豫側子)로서의 형상진단연구 - 담방광체(膽膀胱體)와 남녀형상(男女形象)을 중심으로 -)

  • Kim, Jong-Wan;Kim, Kyung-Chul;Lee, Yang-Tae;Lee, In-Seon;Kim, Kyu-Kon;Chi, Gyoo-Yang
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.3
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    • pp.540-547
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    • 2009
  • There needs disease-predictable signs in order to enable preventive diagnosis and therapy. Then traditional Chinese medicine applies various medical diagnostic equipments used in western medicine to diagnosing sub-healthy state. But such data are not originated from inherent oriental medicine, and not obtained easily in ordinary clinical practice. This paper is to provide synopsis of the ante-disease diagno-therapeutics partly and to show predictable data based on the facial shapes and signs, especially of gall bladder's versus bladder's body and masculine versus feminine shape. Ante-disease means not only the complete healthy state, but also the state unseen any symptoms in macrographically in the course of outbreak of disease. It contains two stages, first one is the former state of disease and second one is untransmitted state of disease. The patterns of ante-disease consist of latent disease, pre-disease, transmission type like senescent syndrome, abnormal reactive syndrome(變證), syndrome of transmission and transmutation. The classification with gall bladder and bladder type manifests the differences of shape, color and size of each organ in comparison of the universal and standard figures of the human being. On the other hand, the classification with masculine and feminine shape contrasts the innate sexual difference and the shape, characteristics originated from in itself. These two classification theories have their own pathologic types and syndrome types with each disease so that disease-predictable data can be constructed based on such a relationship. In addition, this diagnostic method by facial shapes and signs is able to be applied to whole stages from prenatal to present state of disease even if the cause and inducement are not clear. Ante-disease diagno-theraputic system by Gall Bladder's versus Bladder's Body and Masculine versus Feminine Shape is getting more important in the chronic and internal disease in comparison of the acute and traumatic disease. So this study is able to make up for the limit of diagnosis on ante-disease in the field of oriental medicine clinic.

Hyoid Bone Fracture Associated with Hypoglossal Nerve Palsy: A Case Report (설하신경마비를 동반한 설골골절: 증례보고)

  • Kim, Sin-Rak;Park, Jin-Hyung;Han, Yea-Sik
    • Archives of Plastic Surgery
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    • v.38 no.2
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    • pp.199-202
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    • 2011
  • Purpose: Hyoid bone is a U-shaped bone in the anterior of the neck. Hyoid bone fractures are exceedingly rare and represent only 0.002% of all fractures because of its protective position relative to the mandible and its suspension by elastic musculature. We report a patient who presented hyoid bone fracture associated with hypoglossal nerve palsy. We also discuss the possible complication and treatment. Methods: A 69-year-old man was transferred from another institution because of persistent purulent discharge from the left chin. He had a history of trauma in which a knuckle crane grabbed his face and neck in the construction site. A CT scan at the time of the accident demonstrated a comminuted fracture of the right side of the mandible and hyoid bone fracture at the junction between body and right greater cornua. The displaced fracture of hyoid bone and fullness in the pre-epiglottic space were noted, probably indicating some edema. The patient was transferred into ICU after treatment of emergency tracheostomy because the patient showed respiratory distress rapidly. When the patient was hospitalized in our emergency room, he complained of dysphagia and pain when swallowing. On examination of oral cavity, the presence of muscle wasting with fasciculation of the tongue was noted and the tongue deviates to the left side on protruding from the mouth. Pharyngolarygoscopy was performed to make sure that there was no evidence of progressive swelling and pharyngeal laceration. Results: The patient underwent surgical removal of dead and infected tissue from the wound and reconstruction of mandibular bony defect by iliac bone grafting. Hyoid bone fracture was managed conservatively with oral analgesics, soft diet and restricted movement. Hypoglossal nerve palsy was resolved within 7 weeks after trauma without complications. Conclusion: Closed hyoid bone fracture is usually uncomplicated and thus it can be treated conservatively. Surgical intervention for hyoid bone fracture is recommended for patient with airway compromise, pharyngeal perforation and painful symptoms which show no response to conservative care. Furthermore, since respiratory distress syndrome may develop quickly, close observation is required. Besides, hypoglossal nerve palsy is a rarely recognized complication of hyoid bone fracture.

Determination of Operational Parameters for TCE Degradation in Photocatalytic Oxidative Reactors (TCE의 분해를 위한 광촉매 산화반응조의 운전인자 도출에 관한 연구)

  • Hur, Joon-Moo;Cheon, Seung-Yul;Kim, Jong-Soo
    • Korean Journal of Environmental Agriculture
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    • v.22 no.2
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    • pp.124-129
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    • 2003
  • The objectives of this study are to manufacture an efficient $TiO_2$, photocatalyst and to delineate optimum operational parameters for TCE (trichloroethylene) degradation in a photocatalytic oxidative reactor. The $TiO_2$ photocatalyst irradiated by 365 nm UV light is expected to increase degradation of TCE in solution by a series of photocatalytic oxidations in the reactor. A new membrane $TiO_2$ photocatalyst wns eventually developed by coating a mixture of Davan-C(0.24 wt%) and PVA(0.16 wt%) on the surface of slips using the slip-casting method. Results show that increase in the number of coating of $TiO_2$ sol on surface of photocatalysts and in the surface thickness improved the endurance and photocatalysts, but these physical modifications caused significant decrease in the overall degradation efficiency of TCE. Pre-aeration or recirculation of the influents to the reactors containing TCE increased degradation efficiency of TCE. The optimum operational conditions far the surface area of photocatalysts and UV light intensity appeared to be $1.47\;mL/cm^2$ and $225\;W/cm^2{\times}100$, respectively, in the reactor. Based on the overall experimental results, the photocatalytic oxidation of TCE with the new membrane $TiO_2$ photocatalyst is found to be very effective under the operational conditions delineated in this study.

A Study on Workbench-based Dynamic Service De-sign and Construction of Computational Science Engineering Platform (계산과학공학 플랫폼의 워크벤치 기반 동적 서비스 설계 및 구축에 관한 연구)

  • Kwon, Yejin;Jeon, Inho;Ma, Jin;Lee, Sik;Cho, Kum Won;Seo, Jerry
    • Journal of Internet Computing and Services
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    • v.19 no.3
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    • pp.57-66
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    • 2018
  • EDISON ( EDucation-research Integration through Simulation On the Net) is a web simulation service based on cloud compu-ting. EDISON provides that web service and provide analysis result to users through pre-built infrastructure and various calcu-lation nodes computational science engineering problems that are difficult or impossible to analysis as user's personal resources to users. As a result, a simulation execution environment is provided in a web portal environment so that EDISON can be ac-cessed regardless of a user's device or operating system to perform computational science engineering analysis simulation. The purpose of this research is to design and construct a workbench based real - time dynamic service to provide an integrat-ed user interface to the EDSION system, which is a computational science engineering simulation and analysis platform, which is currently provided to users. We also devised a workbench-based user simulation service environment configuration. That has a user interface that is similar to the computational science engineering simulation software environment used locally. It can configure a dynamic web environment such as various analyzers, preprocessors, and simulation software. In order to provide these web services, the service required by the user is configured in portlet units, and as a result, the simulation service using the workbench is constructed.

Behavior Characteristics of Helical Pile in Granite Residual Soil (풍화토 지반에 관입된 나선형 강관말뚝의 거동 특성)

  • Cho, Chunhee;Heo, Yol;Bae, Wooseok
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.3
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    • pp.41-49
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    • 2013
  • The rotate penetration pile is a type of displacement pile: the surrounding soil is displaced when installing the pile, and the pile can exert a large bearing power and pullout force. In addition, it uses displaced soil method that does not generate slime, and its applications are increasing in foreign countries owing to the environmentally friendly characteristics such as small noise and vibration. However, mostly driven piles-which are directly driven to the ground, and bored pile- pre-fabricated piles are buried to prebored underground, are used; however, rotate penetration piles still have limited use. Most of the laboratory tests have been carried out until now to identify the support behavior after installation of piles and ground construction, the evaluating the support behavior is lacking due to the rotation intrusive process of the rotate penetration piles. Therefore, this study used indoor experiments simulating rotation intrusive process in weathered soil, to evaluate the bearing power behavior for the weathered soil, varying the diameter of the helical bearing plates, helical bearing plate spacing, number of the helical bearing plates, and helical bearing plate specifications. As the outcome of this study, the helical pile bearing power evaluation results, change in bearing power in accordance with main specifications, and review on the comparative analysis with the existing theories were provided.

Allowable Compressive Stress of Pre-Tensioned Members with Tee or Inverted Tee Sections at Transfer (T형 및 역T형 단면을 가지는 프리텐션부재의 프리스트레스 도입시 허용 압축응력)

  • Lee, Deuck-Hang;Lee, Jeong-Yeon;Lim, Joo-Hyuk;Kim, Kang-Su
    • Journal of the Korea Concrete Institute
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    • v.23 no.3
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    • pp.353-364
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    • 2011
  • In a previous research performed by the authors, the allowable compressive stress coefficient (K) in pretensioned members with rectangular section at transfer was proposed based on strength design theory. In this study, a subsequent research of an enormous analysis was performed to determine the K factor for Tee and inverted Tee section members, considering the effect of section height (h), section type, amount of tendons ($A_{ps}$), and eccentricity ratio (e/h). Based on the analysis results, the allowable compressive stress coefficients (K) for Tee and inverted Tee section members at transfer were derived, which limit the maximum allowable stresses as 80% and 70% of the compressive strengths at the time of release for Tee section and inverted Tee section, respectively. And these were larger than the allowable stresses specified in domestic and other international codes. In order to verify the proposed equations, they were compared to the test results available in literature and other codes, which showed that the allowable stresses in domestic and international codes are unconservative for the cases with low eccentricity ratios while conservative for those with high eccentricity ratios. The proposed equations, however, estimate the allowable stresses of the Tee and inverted Tee section members reasonably close to test results.

Preliminary study on a spoke-type EPB shield TBM by discrete element method (개별요소법을 활용한 스포크 타입 토압식 쉴드TBM의 예비 해석 연구)

  • Lee, Chulho;Chang, Soo-Ho;Choi, Soon-Wook;Park, Byungkwan;Kang, Tae-Ho;Sim, Jung Kil
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.6
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    • pp.1029-1044
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    • 2017
  • The Discrete Element Method (DEM) is one of the useful numerical methods to analyze the behavior of the ground formation by computing the motion and interaction using particles. The DEM has not been applied in civil engineering but also a wide range of industrial fields, such as chemical engineering, pharmacy, material science, food engineering, etc. In this study, to review a performance of the spoke-type earth pressure balance (EPB) shield TBM (Tunnel Boring Machine), the commercial software based on the DEM technology was used. An analysis of the TBM during excavation was conducted according to two pre-defined excavation conditions with the different rotation speed of a cutterhead. During the analysis, the resistant torque at the face of the cutterhead, the compressive force at the cutterhead and shield surface, the muck discharge at the screw auger were measured and compared. Upon the two kinds of excavation conditions, the applicability of the DEM analysis was reviewed as a modelling method for the TBM.