• Title/Summary/Keyword: Cutting stability

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Study on Analysis for Factors Inducing the Whangryeong Mountain Landslide (황령산 산사태 원인 분석에 대한 연구)

  • 최정찬;백인성
    • The Journal of Engineering Geology
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    • v.12 no.2
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    • pp.137-150
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    • 2002
  • Recently, plane failure mode occurred frequently along the bedding plane having low angle dip about 20 degree when cutting slopes were constructed in sedimentary rock region of the Gyeongsang Basin. Landslide of the Whangryeong Mountain which was occurred at Busan Metropolitan City in 1999 belongs to the category mentioned above. Reconstruction for cutting slope of the Whangryeong Mountain has finished in 2000 and final grade of reconstructed cutting slope is 1:2.0. To analyze slope failure mode for landslide of the Whangryeong Mountain, various analyses were performed such as in-situ investigation and test, drilling, laboratory test, aerial photograph interpretation, X-ray diffraction analysis, and slope stability analysis using Stereographic Projection and Limit Equilibrium methods. As the result, it is identified that tension cracks had been developed one year before the landslide took place. The tension crack semis to be formed by merging several joint sets. It appears that failure blocks broke down along the sliding planes of different layers. Risk of plane failure is conformed as a result of stability analysis using Stereographic Projection and Limit Equilibrium methods in case that greenish gray tuffaceous shales, regared as sliding planes, are weathered. From now on, a detailed investigation is needed for the thin layers which is sensitive to weathering, and stability analysis for this layer is performed at cut slope construction site having similar geological condition.

Structural Stability Analysis of Medical Waste Sterilization Shredder (의료폐기물 멸균분쇄용 파쇄기의 구조적 안정성 분석)

  • Azad, Muhammad Muzammil;Kim, Dohoon;Khalid, Salman;Kim, Heung Soo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.34 no.6
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    • pp.409-415
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    • 2021
  • Medical waste management is becoming increasingly important, specifically in light of the current COVID-19 pandemic, as hospitals, clinics, quarantine centers, and medical research institutes are generating tons of medical waste every day. Previously, a traditional incineration process was utilized for managing medical waste, but the lack of landfill sites, and accompanying environmental concerns endanger public health. Consequently, an innovative sterilization shredding system was developed to resolve this problem. In this research, we focused on the design and numerical analysis of a shredding system for hazardous and infectious medical waste, to establish its operational performance. The shredding machine's components were modeled in a CAD application, and finite element analysis (FEA) was conducted using ABAQUS software. Static, fatigue, and dynamic loading conditions were used to analyze the structural stability of the cutting blade. The blade geometry proved to be effective based on the cutting force applied to shred medical waste. The dynamic stability of the structure was verified using modal analysis. Furthermore, an S-N curve was generated using a high cycle fatigue study, to predict the expected life of the cutting blade. Resultantly, an appropriate shredder system was devised to link with a sterilization unit, which could be beneficial in reducing the volume of medical waste and disposal time, thereof, thus eliminating environmental issues, and potential health hazards.

A Study of Cutting Method of H-Pile for Explosive Demolition of SRC Structure (철골구조물 발파해체를 위한 H형강 절단방법에 대한 연구)

  • Min Hyung-Dong;Lee Yun-Jae;Song Young-Suk;Kim Hyo-Jin
    • Explosives and Blasting
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    • v.23 no.3
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    • pp.83-89
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    • 2005
  • It follows in deterioration of the steel frame structure and becomes remodeling and removal. The construction work characteristic, economical efficiency and stability environment characteristic are planned and considered hereafter control plan of the steel frame structure which is deteriorated currently to cutting mettled plentifully sued on gas cutting of H beam. However it will not be able to apply from the explosives demolition which is makes a weak instantaneously and then collapses the building at the time. In this study, shape charge was used for cutting of the H-beam. That is the element testing to estimate explosives demolition for steel frame structure. As a result, it is found for single-side rutting method, both-sides rutting methods by H-beam thickness and pre-rutting process. It confirmed an affix method and an ease characteristic by fixing tool. Also, it is shown that air blasting decreased about 8dB(A) in order to reduce air blasting used by sand box. However, it will be required to reduce air blasting little more because explosives demolition will be done in urban site.

The Effect of Elastic Therapeutic Taping on Lower Limb Kinematics during a Cross Cutting Movement from Landing in Subjects with Chronic Ankle Instability (탄력 테이핑이 만성 발목 불안정 환자의 착지 후 방향 전환 시 하지 관절 움직임에 미치는 영향)

  • Jo, Tae-Seong;Kim, Tack-Hoon;Choi, Houng-Sik;Roh, Jung-Suk
    • Journal of the Korean Society of Physical Medicine
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    • v.12 no.4
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    • pp.1-9
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    • 2017
  • PURPOSE: This study investigated the effect that an elastic therapeutic taping treatment given to patients with chronic ankle instability had on the vertical ground reaction force, center of pressure, and range of motion in the ankle, knee and hip joints, during a Cross-cutting movement from landing. METHODS: This study analyzed 12 able-bodied adults and 12 patients with chronic ankle instability classified by using the Cumberland tool in the motion analysis laboratory, Hanseo University. The experiment was conducted under two conditions elastic taping and no treatment. In order to analyze the difference between the groups. An independent t-test was performed at p>.01. RESULTS: Plying an elastic therapeutic taping to the patients with chronic ankle instability significantly decreased the range of joint motion in the inversion of the ankle joint, the flexion of the knee joint, and the flexion and internal rotation of the hip joint during a cross-cutting movement from landing in comparison with the able-bodied adults p<.01. This restriction in the range of motion decreased the center-of-pressure trajectory length of patients with chronic ankle instability p>.01. CONCLUSION: An elastic therapeutic taping treatment given to patients with chronic ankle instability causes ankle stability to increase during a cross-cutting movement from landing.

Pattern Development of Skate Pants Allowing for Dynamic Movement and Postures (인체의 동작을 고려한 스케이트 팬츠 패턴 개발)

  • Jeong, Yeon-Hee
    • Korean Journal of Human Ecology
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    • v.17 no.1
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    • pp.115-126
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    • 2008
  • The construction of an athlete's tight-fitting garments is very important to the wearer in terms of athletic performance. Therefore pattern development of tight-fitting garments must allow for the full range of human movement and postures. In this study the relationship between the construction of a skate pants pattern and clothing fitting was explored with the aim of improving the comfort of the clothing. The four male subjects were university students between the ages of 20 to 24. Subjective wear sensations of the experimental garments were rated using a seven-point Likert scale on four consecutive days. While wearing the garments, subjects were asked to take five different postures including waist flexion, sitting and others. A Likert-type scale was used for the evaluation, with 7 points indicating the best fit in tight-fitting pants. Results showed differences in the front-rise length and back-rise length between basic pants(A) and modified pants(B,C,D) were -5.16cm and +5.64cm. Comparing the basic pants pattern(A) with modified pants pattern(B), the latter was superior to basic pants(A) in terms of pressure sensation and closeness of fit, but there was no significant difference. Among the four tight-fitting skate pants, A and B pants were superior to the others in terms of fitting and stability of waist and hip sections. In the case of the skate pants, the number of cutting lines in the pattern had an influence on clothing comfort. A minimum cutting line for tight skate pants was better than a maximum cutting line in terms of clothing comfort.

A Geologic Disasters in Quaternary Volcanic Area, Ulreung-Island (제사기(第四紀) 화산암(火山岩) 분포지역(分布地域)에 빈발(頻發)하는 지질재해(地質災害)에 관(關)하여)

  • Kim, Young Ki
    • Economic and Environmental Geology
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    • v.13 no.2
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    • pp.80-90
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    • 1980
  • A geologic disasters in Ulreung-island is forming along the slope of pyroclastic, deposits and this paper discusses soil mechanics and properties and morphologies of pyroclastic soil. The typers of degradation are determined by cutting the soil and classified genetically. Finally, the range of stability is deduced from dip of slope (${\alpha}$) and lengh of slope (l) as the following;.

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Study on slope stability of waste dump with a weak layer using finite element limit analysis method

  • Chong Chen;Huayong Lv;Jianjian Zhao;Zhanbo Cheng;Huaiyuan Wang;Gao Xu
    • Structural Engineering and Mechanics
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    • v.89 no.3
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    • pp.253-263
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    • 2024
  • Slope stability is generally paid more attention to in slope protection works, especially for slope containing weak layers. Two indexes of safety factor and failure model are selected to perform slope stability. Moreover, the finite element limit analysis method comprehensively combines the advantage of the limit analysis method and the finite element method obtaining the upper and lower bounds of the safety factor and the failure mode under the slope stability limit state. In this study, taking a waste dump containing a weak layer as an engineering background, the finite element limit analysis method is adopted to explore the potential failure mode. Meanwhile, the sensitivity analysis of slope stability is performed on geometrical and geotechnical parameters of the waste dump. The results show that the failure mode of the waste dump slope is two wedges if the weak layer is located on the ground surface (Model A), while the slope can be observed as three wedges failure if the weak layer is below the ground surface (Model B). In addition, both failure modes are highly sensitive to the friction angle of the weak layer and the shear strength of waste disposal, and moderately sensitive to the heap height, the dip angle and cohesion of the weak layer, while the toe cutting has limited effect on the slope stability. Moreover, the sensitivity to the excavation of the ground depends on the location of the weak layer and failure mode.

Application for Environment-friendly Retaining Wall Method Composed with Permanent Ground Anchor and Vertical Precast Panel in Cutting Slope Area (영구앵커와 연직 프리캐스트패널을 사용한 절토사면 친환경옹벽공법의 적용사례)

  • Nam, Hong-Ki;Jung, Hong-Seop
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.87-96
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    • 2010
  • PAP method is a combined measures which consist a anchored retaining wall method with permanent ground anchors and vertical precast concrete panels, step by step on the slope surface. And soil is back filled between slope and vertical precast panels. Therefore, this method is more effective than any other ground anchor reinforcing methods of slope stability, for example cross type concrete block ground anchor or buttress concrete block ground anchor method. Because of increasing effective anchor force and green tree planting.

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Measurement of Thermal Properties of SiC/C Functionally Gradient Materials by Laser Flash Method (레이저 플래쉬 방법에 의한 SiC/C계 경사기능재료의 열물성 측정)

  • Mok, Jae-Gyun;Yu, Jae-Seok
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.5
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    • pp.1679-1688
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    • 1996
  • Laser flash technique was applied to measure thermal properties of FGM made by a CVD method. System stability and reproducibility of this measuring system were proved and calibrated with glassy carbon used as reference material. Specimens was prepared by cutting FGM diagonally. Measurements were performed for a wide range of temperatures up to 1500K. Relative heat capacity of the FGM specimen was scattered with in $\pm$13% at room temperature and at high temperature above 1200K, and $\pm$3% at medium temperature range. On the other hand, thermal diffusivity data showed excellent reproducibility and stability through the whole temperature range. In conclusion, the multi-target radiometer can be applied to measure the thermal properties of non homogeneous materials like FGM.

A Study on the Stability of Chucking System for Machine Tools (공작기계용 Chucking System의 안정성에 관한 연구)

  • 박종권
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1998.03a
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    • pp.135-142
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    • 1998
  • The performances of cutting process is mostly affected by the characteristics of closed loop system constructed with machine tool structure, work piece and tools. The chucking system is very important component in this system to hold work piece correctly in various static and dynamic load condition. Therefore, chucking force and accuracy must be considered carefully, from these reason, this paper describes the stability of chucking system which preserve high stiffness and accuracy of machine tool system.

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