• 제목/요약/키워드: restraint

검색결과 926건 처리시간 0.031초

CGS 공법에 의한 지반침하억제 사례연구 (A Case Study on the Plan for Settlement Restraint by CGS)

  • 천병식;여유현;김우종;황성식;김우철
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2002년도 봄 학술발표회 논문집
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    • pp.611-618
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    • 2002
  • In this study the CGS as an injection method by low slump mortar was performed the pilot test to confirm the applicability of this method and the effectiveness of settlement restraint. From the results, there has been concluded the construction control standard such as an institutional diameter, space, depth, injection materials, Infection pressure etc. Also, there has been estimated the ground improvement effectiveness which has resulted from the field investigation and consolidation test etc. From the results, in the adjacent ground the CGS, generally, has been confirmed to in-crease ground strength to improve the consolidation characteristic obtained from the field investigation and consolidation test. Especially, the CGS which performed the larger stiffness to the ground has been concluded that the settlement restraint to the ground complicates the ground effect which Increases the bearing capacity and stress assignment. So, the CGS can be considered as an effective method to increase the bearing capacity as well as the settlement restraint of soft ground.

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어린이보호용좌석 효과의 실험적 연구 (Experiments of CRS for Safety Improvement)

  • 이재완;박형원;윤경한;박경진
    • 한국자동차공학회논문집
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    • 제11권4호
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    • pp.79-85
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    • 2003
  • The child restraint system is blown to be excellent to reduce child occupant injury in frontal collisions. The effects of the child restraint system are experimently investigated according to FMVSS 213. A sled simulator is utilized with varying restraint types such as 2point, 3point seat belts, forward-facing types and booster types of child restraint systems. The head and chest injuries for various cases are evaluated based on industrial standards. Also, the maximum displacements of the head and the knees are measured by film analysis. Using the results of the test, the effects of the child restraint system is discussed and reduction of child occupant injury is pursued.

Elastic rotational restraint of web-post in cellular beams with sinusoidal openings

  • Durif, Sebastien;Bouchair, Abdelhamid;Bacconnet, Claude
    • Steel and Composite Structures
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    • 제18권2호
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    • pp.325-344
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    • 2015
  • Experimental tests on cellular beams with sinusoidal openings showed two main failure modes around the openings. They concern the formation of four plastic hinges and the local instability of the sinusoidal part of the opening. In parallel, numerical analysis of the sinusoidal part of the opening revealed the existence of an elastic rotational restraint between the intermediate web-post and the adjacent opening panel. The aim of the present study is to present an approach to quantify this rotational restraint. Through the response surface method, a mathematical model is proposed. It shows a great ability to predict the rotational restraint value as a function of the geometrical parameters of the opening. This model can be used to perform an extensive study with various geometrical configurations of beams with the aim to develop a reliable and realistic analytical model predicting the resistance of the sinusoidal openings.

중환자실 환자의 억제대 경험과정 (ICU Patients' Experience Process of Physical Restraint)

  • 김미영
    • 성인간호학회지
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    • 제19권4호
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    • pp.583-592
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    • 2007
  • Purpose: The purposes of this study were to explore and describe the use of restraint on patients and to generate a grounded theory of how the use of restraint affects patients who have been restrained. Methods: Interview data from seven patients with physical restraint was analyzed using the Strauss and Corbin's grounded theory method. Data were collected and analyzed simultaneously. Unstructured and in-depth interviews were conducted retrospectively with patients recalling their memories of ICU following their transfer to general unit. Results: 'Safety belt' was emerged as a core category and it reflected that physical restraint provided a sense of security to patients. On the basis of core category, a model of the experience process of restrained patients in ICU was developed. The experience process were categorized into four stages: resistance, fear, resignation, and agreement. Stages of these proceeds appeared to have been influenced by the nurses' attitude and caring behavior such as the frequency of nurse-patient interaction, repetition of explanation, and empathetic understanding. Conclusion: These findings indicate that patients have mixed feelings towards restraint use, although negative feelings were stronger than positive ones. The result of this study will help nurses make effective nursing intervention.

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Analysis of rotational end restraint for cross-beams of railway through truss bridges

  • Siekierski, Wojciech
    • Steel and Composite Structures
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    • 제35권1호
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    • pp.29-41
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    • 2020
  • Cross-beams of modern through truss bridges are connected to truss chord at its nodes and between them. It results in variable rotational end restraint for cross-beams, thus variable bending moment distribution. This feature is captured in three-dimensional modelling of through truss bridge structure. However, for preliminary design or rapid assessment of service load effects such technique of analysis may not be available. So an analytical method of assessment of rotational end restraint for cross-beam of through truss bridges was worked out. Two cases - nodal cross-beam and inter-nodal cross-beam - were analyzed. Flexural and torsional stiffness of truss members, flexural stiffness of deck members and axial stiffness of wind bracing members in the vicinity of the analyzed cross-beam were taken into account. The provision for reduced stiffness of the X-type wind bracing was made. Finally, general formula for assessment of rotational end restraint was given. Rotational end restraints for cross-beams of three railway through truss bridges were assessed basing on the analytical method and the finite element method (three-dimensional beam-element modelling). Results of both methods show good agreement. The analytical method is able to reflect effects of some structural irregularities. On the basis of the obtained results the general values of rotational end restraint for nodal and inter-nodal cross-beams of railway through truss bridges were suggested.

매스콘크리트에서 타설블럭의 크기(L/H)와 구속체의 탄성계수가 온도응력에 미치는 영향에 관한 검토 (Evaluation on the Effect of the Size of Placing Block(L/H) and Elastic Modulus of Base Structure on the Thermal Stress in Mass Concrete)

  • 강석화;이용호;박칠림
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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    • pp.275-279
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    • 1996
  • In this study, the effect of external restraint on the thermal stresses and thermal cracking mode in mass concrete are analysed using the two major factors affecting external restraint such as the ratio of width go height of the placed structure (L/H) and the elastic modulus of base structure (E). For this parametric study, many cases with different values of L/H and Er are analysed by the FEM program and the co-relationship of the those major factors is examined. To evaluate the effect of external restraint on the thermal behavior of placing structure, internal restraint stress caused by temperature difference is subtracted from total thermal stress. In the case of small value of L/H or Er, it shows as internally restricted mode indicating maximum tensile stress in surface at early age, and the external restraint makes the possibility of thermal cracking higher. However, in the case of the large values of L/H and Er, the crack index at center is smaller than at surface due to the effect of external restraint. Thus, the initial location of the thermal crack is shifted from the surface to the center and the resulting crack is formed at later age.

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필렛 및 맞대기 용접부의 간격 및 구속도에 따른 잔류응력 재분포 특성에 관한 연구 (Study on Residual Stress Redistribution by Changing of Distance and Restraint degree between Fillet and Butt weldment)

  • 진형국;이동주;신상범
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2009년 추계학술발표대회
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    • pp.94-94
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    • 2009
  • The purpose of this study is to identify the principal factor controlling transverse residual stress at the weldment for joining unit hull blocks. In order to do it, the comprehensive FE analyses were carried out to evaluate the effect of distance between fillet and butt weldments, in-plane and out-of-plane restraint degree on the amount and distribution of transverse residual stress in way of the weldments between unit hull blocks. In accordance with FEA results, principal factor controlling the amount of transverse residual stress at the weldments was identified as in-plane restraint degree of butt weldment for unit blocks. The effect of other variables on the transverse residual stress was very small relatively. Based on the results, it can be concluded that the proper distance between fillet weldment for stiffener and butt weldment for joining unit blocks should be determined in consideration of in-plane restraint intensity of butt weldments.

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Distortional buckling of I-steel concrete composite beams in negative moment area

  • Zhou, Wangbao;Li, Shujin;Huang, Zhi;Jiang, Lizhong
    • Steel and Composite Structures
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    • 제20권1호
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    • pp.57-70
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    • 2016
  • The predominant type of buckling that I-steel concrete composite beams experience in the negative moment area is distortional buckling. The key factors that affect distortional buckling are the torsional and lateral restraints by the bottom flange. This study thoroughly investigates the equivalent lateral and torsional restraint stiffnesses of the bottom flange of an I-steel concrete composite beam under negative moments. The results show a coupling effect between the applied forces and the lateral and torsional restraint stiffnesses of the bottom flange. A formula is proposed to calculate the critical buckling stress of the I-steel concrete composite beams under negative moments by considering the lateral and torsional restraint stiffnesses of the bottom flange. The proposed method is shown to better predict the critical bending moment of the I-steel composite beams. This article introduces an improved method to calculate the elastic foundation beams, which takes into account the lateral and torsional restraint stiffnesses of the bottom flange and considers the coupling effect between them. The results show a close match in results from the calculation method proposed in this paper and the ANSYS finite element method, which validates the proposed calculation method. The proposed calculation method provides a theoretical basis for further research on distortional buckling and the ultimate resistance of I-steel concrete composite beams under a variable axial force.

중환자실에서 피부손상을 감소시키기 위한 억제대 개발 및 적용효과 (Effect of a New Developed Physical Restraint to Reduce Skin Injury in Intensive Care Units)

  • 문정숙;이경남;이동숙
    • 기본간호학회지
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    • 제18권1호
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    • pp.28-36
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    • 2011
  • Purpose: The purpose of this study were to develop a new restraint for the intensive care units (ICU) and to investigate the application effect in comparison with a control group using existing restraints. Method: A non-equivalent control group non-synchronized quasi-experimental research design was used. The participants were 40 (control 20, experimental 20) patients who were recruited by convenience sampling the ICU of a university hospital. To avoid contamination of the experiment, data for the control group were collected prior to the experimental group. Measurement variables were edema and skin damage (redness and abrasion) at the application site, and nurses' perceived convenience in applying restraints. Results: Three days after applying the restraint, amount of edema at the application site was small and incidence of skin damage decreased in the experimental group in comparison with the control group. Also, score for application convenience measured by the nurses was higher in for the newly developed restraint than for existing restraints. Conclusion: Results indicate that the newly developed restraint has lower effects such as edema and skin damage and is more convenient compared with existing restraints, and is therefore recommended for patients in the ICU.

흰쥐에서 구속스트레스에 대한 우루소데옥시콜린산의 항스트레스 효과 (Anti-stress Effects of Ursodexycholic Acid on the Restraint Stress in Rats)

  • 조태순;이선미;염제호;유은주;임승욱;장병수;김영만;유영효;박명환
    • 약학회지
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    • 제39권5호
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    • pp.548-553
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    • 1995
  • Effects of restraint stress and its modulations by ursodeoxycholic acid(UDCA) were evaluated on some biochemical and biophysical parameters in rats. Restraint stress induced elevations in blood alkaline phosphatase (ALP). cholesterol (CHOL), aspartate transaminase (GOT), alanine transaminase (GPT), lactate dehydrogenase (LDH) levels. It was also caused adrenal hypertrophy, decrease in weight of spleen and contents of ascorbic acid in stressed rats. As a results, stress indicators such as spleen, ascorbic acid, GOT, GPT, LDH were fastly changed after imposing stress, but those such as ALP, CHOL, adrenal were induced relatively later. UDCA was tested if it has an inhibitory effect against 18-hr restraint induced stress. UDCA lowered ALP, CHOL, LDH level and also effectively elevated the ascorbic acid contents in 25 mg/kg dosage of UDCA. In organ weights. the restraint stress induced increases in spleen and adrenal were attenuated by UDCA in 50 mg/kg dosage. However. stress-induced GOT and GPT levels were unaffected by UDCA.

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