• Title/Summary/Keyword: Foundation Practice

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Field measurements of wind-induced transmission tower foundation loads

  • Savory, E.;Parke, G.A.R.;Disney, P.;Toy, N.;Zeinoddini, M.
    • Wind and Structures
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    • v.1 no.2
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    • pp.183-199
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    • 1998
  • This paper discusses some of the findings arising from long-term monitoring of the wind effects on a transmission tower located on an exposed site in South-West England. Site wind speeds have been measured, together with the foundation loads at the base of each of the four legs. The results show good correlation between the wind speeds and leg strains (loads) for a given wind direction, as expected, for wind speeds in excess of 10 m/s. Comparisons between the measured strains and those determined from the UK Code of Practice for lattice towers (BS8100), for the same wind speed and direction, show that the Code over-estimates most of the measured foundation loads by a moderate amount of about 14% at the higher wind speeds. This tends to confirm the validity of the Code for assessing design foundation loads. A finite element analysis model has been used to examine the dynamic behaviour of the tower and conductor system. This shows that, in the absence of the conductor, the tower alone has similar natural frequencies of approximately 2.2 Hz in the both the first (transversal) and second (longitudinal) modes, whilst for the complete system and conductor oscillations dominate, giving similar frequencies of approximately 0.1 Hz for both the first and second modes.

Performance of under foundation shock mat in reduction of railway-induced vibrations

  • Sadeghi, Javad;Haghighi, Ehsan;Esmaeili, Morteza
    • Structural Engineering and Mechanics
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    • v.78 no.4
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    • pp.425-437
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    • 2021
  • Under foundation shock mats have been used in the current practice in order to reduce/damp vibrations received by buildings through the surrounding environment. Although some investigations have been made on under foundation shock mats performance, their effectiveness in the reduction of railway induced-vibrations has not been fully studied, particularly with the consideration of underneath soil media. In this regard, this research is aimed at investigating performance of shock mat used beneath building foundation for reduction of railway induced-vibrations, taking into account soil-structure interaction. For this purpose, a 2D finite/infinite element model of a building and its surrounding soil media was developed. It includes an elastic soil media, a railway embankment, a shock mat, and the building. The model results were validated using an analytical solution reported in the literature. The performance of shock mats was examined by an extensive parametric analysis on the soil type, bedding modulus of shock mat and dominant excitation frequency. The results obtained indicated that although the shock mat can substantially reduce the building vibrations, its performance is significantly influenced by its underneath soil media. The softer the soil, the lower the shock mat efficiency. Also, as the train excitation frequency increases, a better performance of shock-mats is observed. A simplified model/method was developed for prediction of shock mat effectiveness in reduction of railway-induced vibrations, making use of the results obtained.

Estimation of Kinematic Soil-Structure Interaction for Deeply Embedded Foundations (깊은 직접기초의 지반-구조물 상호작용 평가)

  • Kim Seng-Hyun
    • Journal of the Korean Geotechnical Society
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    • v.22 no.4
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    • pp.105-111
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    • 2006
  • Earthquake strong motion recordings from two deeply embedded sites with instrumented structures and free-field accelerographs are used to evaluate variations between foundation-level and free-field ground motions. The foundation free-field ground motion variations are quantified in terms of frequency-dependent transmissibility function amplitude, ${\mid}H\mid$. Comparisons are then performed with an analytical model for the assumed conditions of a rigid base slab and a vertically propagating, coherent incident wave. The limiting assumptions of the model are not strictly satisfactory for actual structures, and the results of the analysis reflect not only incoherence effects, but also possible foundation flexibility and wave inclination effects. Nonetheless, the simple analytical model is in an acceptable agreement with the empirical analysis and appears to be applicable in practice.

A Survey Research to Diagnose the Problems of Mathematics Education ID Korea (우리나라 수학교육의 문제점 진단을 위한 조사 연구)

  • Park, Kyung-Mee;Kim, Dong-Won
    • The Mathematical Education
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    • v.50 no.1
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    • pp.89-102
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    • 2011
  • The purpose of this study is to diagnose the problems of mathematics education in Korea by conducting an in-depth analysis of international comparative studies, a Delphi method, and a survey. Further analysis of TIMSS and PISA results also reveals several negative aspects of mathematics education practice in Korea. The mathematics education experts' opinions collected by Delphi method were classified into 12 categories: private education and test-driven education, curriculum and textbooks, lessons, evaluation, teacher, learner, teaching aid and facilities. affective aspects of mathematics, discrepancy between a theory and a practice, preservice/inservice teacher education and teacher employment test, education policy, and overall. Another survey was conducted to focus more on the development of curriculum which is a pending issue. Considering the fact that mathematics education should contribute to improve practical aspect as well as elaborate theoretical aspect, this study lays a foundation of improvement of mathematics education in Korea.

Influence of Health Literacy and Health Empowerment on Health Behavior Practice in Elderly Outpatients with Coronary Artery Disease (외래 통원 관상동맥질환 노인환자의 건강정보이해능력, 건강임파워먼트가 건강행위이행에 미치는 영향)

  • Ko, Moung Sil;Kang, Kyung Ja
    • Journal of Korean Clinical Nursing Research
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    • v.24 no.3
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    • pp.293-302
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    • 2018
  • Purpose: The purpose of this descriptive study was to identify the influence of health literacy and health empowerment on health behavior practice in elderly patients with coronary artery disease. Methods: 239 elderly outpatients older than 65 years of age were included. The data were analyzed with descriptive statistics including independent t-test, ANOVA, and hierarchical regression. Results: Major factors having a significant impact on health behavior practice were health literacy (${\beta}=.26$, p<.001) and health empowerment (${\beta}=.32$, p<.001). Health literacy was increased by 4.7% after controlling for general and health-related characteristics. Health empowerment increased by 5.9% after controlling for general and health-related characteristics, and health literacy. The two variables explained 35% of the variance in health behavior practice (F=7.74, p<.001). Conclusion: The main findings of this study can be utilized as the foundation for developing programs to promote health empowerment and health behavior practice of the elderly population. Furthermore, the results of the study can also be used to establish health-related strategies.

Appraisal of Clinical Practice Guidelines of Temporomandibular Disorders Using AGREE II (Appraisal of Guidelines for Research & Evaluation II) (AGREE II를 이용한 턱관절 장애의 국내외 기개발 임상진료지침의 평가)

  • Yoon, Ye-Ji;Park, Hye-Sung;Kim, Hyungsuk;Jeon, Junyung;Park, Jae-Hyun;Shin, Woochul;Kim, Seyoon;Bae, Jun-hyeong;Yun, Jung-min;Kim, Koh-Woon;Ha, In-Hyuk;Lee, Yoon-Jae;Kim, Me-riong;Song, Mi-Yeon;Cho, Jae-Heung
    • Journal of Korean Medicine Rehabilitation
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    • v.27 no.4
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    • pp.67-74
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    • 2017
  • Objectives This study is aimed to identify and evaluate the already developed clinical practice guidelines (CPGs) of temporomandibular disorders (TMD) and contribute to making decisions in developing Korean medicine CPG of TMD. Methods We searched electronic database and selected CPGs of TMD according to the inclusion and exclusion criteria. Then, we made appraisal of selected CPGs by using AGREE II (Appraisal of Guidelines for Research & Evaluation II). Results Four CPGs are included and appraised with AGREE II. Among 6 domains of AGREE II, all CPGs failed to score over 60% in four domains. Only one CPG mentioned acupuncture as an adjunctive treatment for myofascial TMD. Conclusions It is difficult to indicate that included CPGs are with sufficient quality to recommend and it appears not to be appropriate to apply these already developed CPGs in Korean medicine clinical fields. Therefore, developing a new Korean medicine clinical practice guideline of TMD is required.

Foundation Modeling Considering the Soil-Structure Interaction (지반-구조물 상호작용을 고려한 기초모델링)

  • Lee, Yong-Jei;Kim, Tae-Jin;Maria, Feng
    • Journal of the Earthquake Engineering Society of Korea
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    • v.16 no.3
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    • pp.13-22
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    • 2012
  • Even with its significant influence on the dynamic analysis and foundation design of structures, sometimes the soil-structure interaction has been ignored during the design process. One of the reasons is due to the fact that the modeling procedures are too complicated to meet the requirements in practice. In this study, using the Cali(IT)2 building in California with high and frequent seismic activities, the analysis differences for different boundary conditions are reviewed. The Beam on Nonlinear Winkler Foundation Model, one of the foundation modeling methods, is modified for easy use by the Linear Matrix Inequalities Model Reduction Technique. The product of the proposed process is applied to create the Finite Element Model. The results show fairly good agreement with the real data acquired from the Cal(IT)2 building.

Methods for Nonlinear Structural Response Analysis of Offshore Structures with Passive Fire Protection under Fires (해양플랜트 구조물의 화재 사고 시 PFP 효과를 고려한 비선형 구조응답 해석 기법에 대한 연구)

  • Kim, Jeong Hwan;Lee, Dong Hun;Ha, Yeon Chul;Kim, Bong Ju;Seo, Jung Kwan;Paik, Jeom Kee
    • Journal of Ocean Engineering and Technology
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    • v.28 no.4
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    • pp.294-305
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    • 2014
  • In offshore structures, fire is one of the most important hazardous events. The concern of fires has recently been reflected in the rules and quantified risk assessment based design practice. Within the framework of quantified risk assessment and the management of offshore installations, therefore, more refined computations of the consequences or hazardous action effects due to fire are required. To mitigate fire risk, passive fire protection(PFP) is widely used on offshore structures. This study presents methods for a nonlinear structural response analysis considering the PFP effects under fires. It is found that a structural response analysis is most likely to use valuable technology for the optimization and design of offshore structures with PFP. Thermal and structural response analyses have been performed using LS-DYNA and FAHTS/USFOS. The results of these structural response analyses are compared with each other.

Component Analysis and Toxicity Study of Combined Cultivated Wild Ginseng Pharmacopuncture (산양산삼복합약침의 표준화 및 급성독성시험)

  • Baek, Sang-hyun;Lee, In-hee;Kim, Min-jeong;Kim, Eun-jee;Ha, In-hyuk;Lee, Jin-ho;Le, Jae-woong
    • The Journal of Internal Korean Medicine
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    • v.36 no.2
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    • pp.189-199
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    • 2015
  • Objectives: The marker substances of cultivated wild ginseng pharmacopuncture that may not be detected during the process of steaming remain controversial. We developed a combined cultivated wild ginseng pharmacopuncture that contains all the marker substances. The aim of this experiment was to investigate the marker substances and test the toxicity of the combined cultivated wild ginseng pharmacopuncture. Methods: The marker substances were detected using HPLC. Intravenous injection toxicity studies were conducted at Medvill, an authorized institution for non-clinical studies, under the regulations of Good Laboratory Practice. We observed survival rates, abnormal behaviors, weight changes, gross findings in autopsy, blood biochemical properties, and histological abnormalities of organs such as the liver and kidney. Results: HPLC data showed that ginsenosides Rg1, Rb1, and Rg3 were detected at concentrations of 19.29, 47.64, and 3.02 μ g /ml, respectively. Administration of combined cultivated wild ginseng pharmacopuncture resulted in no dead animals or significant toxicological changes. Conclusions: The combined cultivated wild ginseng pharmacopuncture contains all the marker substances and is a relatively safe treatment medium. Further studies should be conducted to confirm the present findings.

A Survey on Patient's Experience on Health Care Utilization and Perception of Health Care System for Developing of a Korean Medicine Clinical Practice Guideline for Traffic Injuries (교통사고상해증후군 한의표준임상진료지침 개발을 위한 환자의 의료이용 경험과 의료체계 인식도 설문조사 연구)

  • Park, Sun-Young;Lee, Sang-Hyun;Heo, In;Hwang, Man-Suk;Kim, Koh-Woon;Cho, Jae-Heung;Park, Kyoung Sun;Ha, In Hyuk;Shin, Byung-Cheul
    • Journal of Korean Medicine Rehabilitation
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    • v.30 no.2
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    • pp.139-152
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    • 2020
  • Objectives To explore the traffic injury patients' experience on health care utilization of Korean Medicine (KM) practice and perception of health care system for developing a Korean medicine clinical practice guideline (CPG) of traffic injuries by survey method. Methods Two hundred ten patients in suffering from traffic injuries were surveyed from September 1st, 2019 to January 31th, 2020 at 2 University Hospitals (Pusan National Korean Medicine Hospital and Kyung Hee Korean Medicine Hospital at Gangdong) and 1 Spine Specialty Hospital (Jaseng Hospital of Korean Medicine). A structured questionnaire of experience on health care utilization of KM practice and perception of health care system of was distributed to responders by visits and all data were statistically analysed. Results Survey results showed high satisfaction of patients with the experience of KM treatments in order of daoyin exercise (7.8±2.3), chuna manual therapy (7.7±4.0), pharmacoacupuncture (7.4±3.0) etc. Safety concerns were reported in 9.1% subjects and 205 (97.6%) patients answered that collaboration with KM and western medicine is necessary for patients with traffic injuries. For the patients' requirement for extending insurance coverage, the most required therapy was chuna manual therapy (57.5%) and pharmacoacupuncture (42.0%). Conclusions This study presented the realistic patient-centered perception of KM practice and health care system in Korea. These results will provide basic data to be reflected in the process of adaptation for the revision of Korean Medicine CPG for traffic injuries.