• Title/Summary/Keyword: Static safety

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Characteristics of Bearing Capacity and Reliability-based Evaluation of Pile-Driving Formulas for H Pile (H-pile의 지지력 특성 및 동역학적 공식의 신뢰도 평가)

  • 오세욱;이준대
    • Journal of the Korean Society of Safety
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    • v.18 no.1
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    • pp.81-88
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    • 2003
  • Recently, pile foundations were constructed in rough or soft ground than ground of well condition thus it is important that prediction of ultimate bearing capacity and calculation of proper safety factor applied pile foundation design. This study were performed to dynamic loading tests for the thirty two piles at four different construction sites and selected pile at three site were performed to static loading tests and then compare with measured value and value of static and dynamic loading tests. The load-settlement curve form the dynamic loading tests by CAPWAP was very similar to the results obtained from the static load tests. Based on dynamic and static loading tests, the reliability of pile-driving formula were analyzed and then suggested with proper safety factor for prediction of allowable bearing capacity in this paper.

Dynamic response of coal and rocks under high strain rate

  • Zhou, Jingxuan;Zhu, Chuanjie;Ren, Jie;Lu, Ximiao;Ma, Cong;Li, Ziye
    • Geomechanics and Engineering
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    • v.29 no.4
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    • pp.451-461
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    • 2022
  • The roadways surrounded by rock and coal will lose their stability or even collapse under rock burst. Rock burst mainly involves an evolution of dynamic loading which behaves quite differently from static or quasi-static loading. To compare the dynamic response of coal and rocks with different static strengths, three different rocks and bituminous coal were selected for testing at three different dynamic loadings. It's found that the dynamic compression strength of rocks and bituminous coal is much greater than the static compression strength. The dynamic compression strength and dynamic increase factor of the rocks both increase linearly with the increase of the strain rate, while those of the bituminous coal are irregular due to the characteristics of multi-fracture and heterogeneity. Moreover, the absorbed energy of the rocks and bituminous coal both increase linearly with an increase in the strain rate. And the ratio of absorbed energy to the total energy of bituminous coal is greater than that of rocks. With the increase of dynamic loading, the failure degree of the sample increases, with the increase of the static compressive strength, the damage degree also increases. The static compassion strength of the bituminous coal is lower than that of rocks, so the number of small-scale fragments was the largest after bituminous coal rupture.

A Study on the Oxygen Saturation Level Changes in the Blood Exposed to the Static Magnetic Field (자속에 노출된 인체의 혈중 산소 포화농도의 변화에 관한 연구)

  • Jung, Yong-Chul;Lee, Dong-Hoon
    • Journal of the Korean Society of Safety
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    • v.22 no.6
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    • pp.87-90
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    • 2007
  • The effects of static magnetic field on the human biological system are becoming increasingly more important with the adaption of static magnet in the medical community. It is the goal of this paper to review the effects of static magnetic fields on oxygen saturation level in blood. The results of this paper show that the oxygen saturation level increased in the blood in index finger when the static magnetic dipole was fitted on index finger.

Compare Seismic Coefficient Method and Seismic Response Analysis for Slope during Earthquake (지진시 사면안정해석에 있어서의 진도법과 지진응답해석의 결과 비교)

  • 박성진;오병현;박춘식;황성춘
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.193-200
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    • 2000
  • Numerical analysis of slope stability is presented using slice method, static seismic analysis methods, and earthquake response analysis methods. Static seismic force is considered as 0.2g while vertical static seismic force is not considered in analysis. For earthquake response analysis, Hachinohe-wave is applied. Safety factor calculated using slice method for failure surface. Calculating methods are Bishop's method and Janhu's method. Static seismic analysis was applied using Mhor-Coulomb model and earthquake response analysis was applied using non-linear elastic model.

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Structural Safety Evaluation for Static Strength of Thin Plate RC Member with High Strength Concrete (고강도 콘크리트를 적용한 얇은 RC 판부재의 정적 강도 안전성 평가)

  • Hwang, Hoon-Hee;Park, Sung-Yong
    • Journal of the Korean Society of Safety
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    • v.32 no.5
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    • pp.69-75
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    • 2017
  • Structural safety evaluation for static strength of thin plate RC member with high strength concrete is conducted in this study. Static strengths were predicted and compared with the experimental values. Predicted values were calculated by the evaluation formula based on the punching shear behavior and the yield line theory which can appear in the plate members. Static load tests were carried out for the specimens with high strength concrete and the test results were compared with the required performance in design. The comparison results show that the specimens with high strength concrete have sufficient structural safety for flexural and punching shear performance required in design. High strength concrete specimens exhibited excellent strength despite their small thickness. The range of concrete strengths applied in this study was about 60 MPa to 100 MPa.

Simulation Study on the Safety of a Fastening Device of Agricultural By-product Collector (동역학 시뮬레이션을 통한 농업부산물 수집기 체결장치의 안전성 분석)

  • Jeong-Hun Kim;Seok-Joon Hwang;Ju-Seok Nam
    • Journal of Drive and Control
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    • v.20 no.3
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    • pp.42-49
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    • 2023
  • In this study, the safety of fastening device for the agricultural by-product collector was evaluated according to the driving ground conditions by deriving the stress, static safety factor, and fatigue life using dynamic simulation. A 3D modeling of agricultural by-product collector was carried out, and simulation model was developed by applying the material properties. As a result of dynamic simulation, the magnitude of the maximum stress generated in the fastening device was the highest when driving on the flat off-road, followed by sloped pave-road and flat pave-road. Static safety factor and fatigue life were the highest when driving on the flat pave-road, followed by sloped pave-road and flat off-road. The safety of fastening device was confirmed that static safety factor was more than 1.0 and service life exceeded 9 years in all driving ground conditions.

Study on Flight Test Practice of the Small Civil Airplane Development for Pitot-Static System's Error Identification (소형 항공기 개발 동정압계통 오차 확인 비행시험 사례)

  • Kim, Chanjo;Seo, Jihan;Lee, Wonjoong
    • Journal of Aerospace System Engineering
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    • v.7 no.3
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    • pp.33-38
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    • 2013
  • The air data measured from the static pressure, the dynamic pressure and etc. of an airplane is used for calculation of many flight parameters(altitude and airspeed and so on) and these values applied to flight safety and navigation flight. The pitot-static system of the development airplane is calibrated by finding of pitot-static system's error using tower fly-by, trailing cone method and etc. This paper is describing for the introduction of the trailing cone method and major items for test planning, preparation, operation and results for air data calibration flight test performed, considering efficiency and safety during KC-100 development project.

Design and Implementation of Software Vulnerability Analysis Algorithm through Static Data Access Analysis

  • Lim, Hyun-il
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.8
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    • pp.69-75
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    • 2015
  • Nowadays, software plays various roles in applications in wide areas. However, the security problems caused by software vulnerabilities increase. So, it is necessary to improve software security and safety in software execution. In this paper, we propose an approach to improve the safety of software execution by managing information used in software through static data access analysis. The approach can detect the exposures of secure data in software execution by analyzing information property and flows through static data access analysis. In this paper, we implemented and experimented the proposed approach with a base language, and verify that the proposed approach can effectively detect the exposures of secure information. The proposed approach can be applied in several areas for improving software safety by analysing vulnerabilities from information flows in software execution.

Quasi-static Analysis of Vehicle Seatbelt Using Analysis of Variance and Improvement of Tensile Test Correlation (분산 분석을 이용한 자동차 안전벨트 준정적 해석과 인장시험 상관성 개선)

  • Lee, Kwangseop;Eo, Youngwoo;Kim, Samsung;Kim, Dooyong;Song, Taeckrim;Lee, Kyeongsang
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.3
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    • pp.273-278
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    • 2016
  • This study makes a relative comparison of the results of tensile test and quasi-static analysis using AGL(Adjuster Guide Loop) model that plays a role in adjusting the height of shoulder belt, of the components of the vehicle seatbelt system and attempts to propose a method of reducing the error rate of the quasi-static analysis technique effectively. This study selects two major factors affecting the result of an analysis, draws the result of analysis through the method of experimental design, one of the statistical techniques and understands the contribution rate of the major factors affecting the result of the analysis through ANOVA(Analysis of Variance).

Derivation of Cause Variables necessary for Electrostatic Fire/Explosion Risk Assessment and Accident Investigation (정전기 화재·폭발 위험성평가 및 사고조사에 필요한 발생원인 변수 도출)

  • Junghwan Byeon;Hyeongon Park
    • Journal of the Korean Society of Safety
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    • v.39 no.2
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    • pp.9-21
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    • 2024
  • Static-electricity-induced fires and explosions persistently occur every year, averaging approximately 80 and 20 cases annually according to fire statistics provided by the National Fire Agency and industrial accident statistics provided by the Ministry of Employment and Labor, respectively. Despite the relatively low probabilities of these accidents, their potential risks are high. Consequently, effective risk assessment methodologies and accident investigation strategies are essential for efficiently managing static-electricity hazards in fire- and explosion-prone areas. Accordingly, this study aimed to identify the causal variables essential for accident investigations, thereby facilitating risk assessments and the implementation of effective recurrence prevention measures to mitigate static-electricity hazards in fire-and explosion-prone regions. To this end, industrial accident statistics recorded over the past decade (2012 to 2021) by the Ministry of Employment and Labor were analyzed to identify major fire and explosion incidents and related industrial accidents wherein static electricity was identified as a potential ignition source. Subsequently, relevant investigation reports (63 cases) were thoroughly analyzed. Based on the results of this analysis, existing electrostatic fire and explosion risk assessment techniques were refined and augmented. Moreover, factors essential for investigating electrostatic fire and explosion disasters were delineated, and the primary causal variables necessary for effective risk assessments and scientific investigations were derived.