• Title/Summary/Keyword: resistance capacity

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Estimation of Ultimate Lateral Resistance for Lateral Loaded Short Piles Using CPT Results in Sand (CPT결과를 이용한 사질토지반에 관입된 짧은 단일말뚝의 극한수평단위지지력 산정)

  • Kim, Min-Kee;Hwang, Sung-Wook;Kyung, Du-Hyun;Lee, Jun-Hwan
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1083-1086
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    • 2008
  • In this study, Estimate solutions of ultimate lateral resistances for lateral loaded piles are proposed using cone penetration values, $q_c$ values, as CPT results. Cone penetration values, $q_c$ values measured on clean sand layers, are represented by factors for relative densities, axial stresses, and lateral stresses which are important on analysis of sandy soil layers. Also, these factors are same factors to consider existed estimations of ultimate lateral capacity. In this study, estimation of ultimate lateral capacity for lateral loaded piles using CPT results is proposed, and this estimation is verified by adequate analysis for effective reliability.

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Optimum Reliablity Based Design Criteria for Bridge Cassion Foundation (교량케이슨기초의 최적신뢰성 설계 규준)

  • 손용우;신형우;이증빈;정철원
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1992.10a
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    • pp.79-89
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    • 1992
  • This study is directed to propose a stability analysis and Design Criteria for Bridge Caisson foundations, with Could possibly replace the traditionals W.S.D. provisions of the Current Code, based on the FBOR(Load Factors based on optimum Reliability). The optimum reliability indices(Vertical bearing Capacity : $\beta$opt : 3.19, Lateral bearing Capacity : $\beta$opt= 3.15(ordinary), $\beta$opt : 2.93 (earthquake), Shearing resistance Capacity ; $\beta$opt : 2.87) are Selected as optimal Values Considering our practice base on the Calibration with the current Bridge Caisson foundation design Safety provisions, Load and resistance factors are measure by Using the proposed uncertainties and the Selected optimum reliability indices. furthermore, a set of nominal safety factors are proposed for the U.S.D. design provisions.

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A Study on the Electrochemical Properties of the Cathode upon Different Kinds of Activated carbon in Zinc/Air Battery (활성탄 종류에 따른 아연공기전지용 Cathode의 전기화학적 특성 연구)

  • 김지훈;엄승욱;문성인;윤문수;김주용;박정식;박정후
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.4
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    • pp.415-421
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    • 2004
  • The voltage profile of Zinc/Air battery during discharge has very flat pattern in a given voltage range, But, if not enough the porosity in cathode, as a result of that capacity, energy and discharge voltage of batteries become low. Therefore, we focused the pore effects in activated carbon for cathode. We examined discharge voltage, specific capacity, specific energy, resistance and characteristics during the GSM pulse discharge upon different kinds of activated carbon in Zinc/Air battery, Also we measured porosity of the air cathode according to the ASTM. So we achieved improvement of specific capacity, specific energy and discharge voltage according to increase meso pores of activated carbon. We found the optimized activated carbon material for Zinc/Air battery.

Eccentric Load Resistance of Washbasin Attached to ALC Block Wall (ALC 블록 벽체의 세면기 부착에 따른 편심하중 저항성 평가)

  • Park, Jun-Hyeong;Lee, Duck-Ju;Kim, Hyun;Chol, Soo-Kyung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.05a
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    • pp.12-13
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    • 2019
  • The bearing capacity of the wall against the eccentric load when the washbasin was attached on the ALC block wall was tested. Test methods are BS EN 14688 and BS 5234-2. Tests in accordance with BS EN 14688 showed that the holding capacity of steel was much stronger and more stable when HA-II (chemical anchor) was used than when the washbasin was fixed using HA-I (plastic anchor). As an experimental result according to the Annex K of BS 5234-2, the bearing capacity of ALC block wall corresponded to the "stage in which the force works(performance grade) 1,500N" for all of the cases where a washbasin is fixed using two types of the wall's dedicated anchors(HA-I and HA-II).

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Simple equations for the calculation of the temperature within the cross-section of slim floor beams under ISO Fire

  • Zaharia, R.;Franssen, J.M.
    • Steel and Composite Structures
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    • v.13 no.2
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    • pp.171-185
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    • 2012
  • The calculation of fire resistance for a composite structural element comprises the calculation of the temperature within its cross-section and of the load bearing capacity, considering the evolution of the steel and concrete mechanical properties, function of the temperature. The paper proposes a method to calculate the bending capacity under ISO fire, for Slim Floor systems using asymmetric steel beams, with a wider lower flange or a narrow upper flange welded onto a half hot-rolled profile. The temperatures in the cross-section are evaluated by means of empirical formulas determined through a parametrical analysis, performed with the special purpose non-linear finite element program SAFIR. Considering these formulas, the bending capacity may be calculated, using an analytical approach to determine the plastic bending moment, for different fire resistance demands. The results obtained with this simplified method are validated through numerical analysis.

An Exploration on Prescription of Resistance Training for Geriatric Physical Therapy (노인물리치료를 위한 저항트레이닝 처방에 대한 탐색)

  • Shin Hong-Cheul;Jeong Dong-Hyuk
    • The Journal of Korean Physical Therapy
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    • v.15 no.1
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    • pp.61-81
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    • 2003
  • There can be little dissension that the ultimate goal of all physical therapy interventions with the elderly is to restore or maintain the highest level of function possible for the individual. Whenever physical therapists take on this challenge, they assist elders in maintaining their identities as competent adults. Advancing age is associated with profound changes in body composition, including increased fat mass, decreased fat-free mass(particularly muscle), decreased total body water and decreased bone density. Along with these changes in body compositions, and perhaps as a direct result of them, elderly people have lower energy needs, reduced strength and functional capacity and a greatly increased risk for such diseases as noninsulin-dependent diabetes mellitus and osteoporosis. Resistance training is considered a promising intervention for reversing the loss of muscle function and the deterioration of muscle structure that is associated with advanced age. This reversal is thought to result in improvements in functional abilities and health status in the elderly by increasing muscle mass, strength and power and by increasing bone mineral density. In the past couple of decades, many studies have examined the effects of Resistance training on risk factors for age-related diseases or disabilities. We have explored the positive and negative aspects of older adults' participation in resistance training programs. The benefits to older adults are reported to be increased strength, endurance, muscle capacity, and flexibility; more energy; and improved self-image and confidence. The negative aspects include some pain or stiffness and other nonspecific problems. The positive and negative aspects of resistance training are therefore very similar to those in younger populations. Scientific investigations over the past 10 years have demonstrated that resistance training can be safely and successfully implemented in older populations. Even the frail and very sick elderly can benefit and improve their quality of life. Proper design and progression of a resistance training program for older adults is vital to optimal benefits from resistance exercise. The results of data provided by this research on resistance training for health shows that there is enough existing evidence to conclude that resistance training, particularly when incorporated into a comprehensive fitness program, can offer substantial health benefits which can be obtained by persons of all ages. These benefits, including improvements in functional capacity, translate into an improved quality of life.

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A Study on the Load Sharing Ratio and the Settlement of Prebored Open-Ended Steel Pipe Piles (매입 개단 강관말뚝의 하중분담률과 침하량 분석 연구)

  • Chea min Kim;Ki hwan Kim;Do kyun Yoon;Youngkyu Choi
    • Journal of the Korean Geosynthetics Society
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    • v.22 no.1
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    • pp.39-51
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    • 2023
  • The bearing capacity of the prebored pile has been studied by many researchers. However, The bearing capacity of the prebored pile has been studied by many researchers. However, comparative studies between design data and pile load test data on the load sharing ratio and the settlement were insignificant. Therefore, the design data and the static load test results were compared for the prebored open-end steel piles. In the compressive static pile load test, the load sharing ratios of the base resistance and the shaft resistance were 13%~40% and 60%~87%, respectively and the settlements were measured 2.2mm~4.7mm. In the current bearing capacity calculation formula, the base resistance was shared between 54% and 75%, and the shaft resistance was shared between 25% and 46% and the settlements were calculated about 19.8mm~23.6mm. The settlement in the current bearing capacity calculation formula was 321% to 776% (average : 445%) larger than the settlement in the result of load test. When the settlement were calculated using the load sharing ratio in the pile load tests, it was 137% to 525% larger than the test settlement, and it was as large as 204% on average. It was confirmed that an appropriate evaluation of the load sharing ratio had an important effect on the calculation of pile settlement.

Fire-after-earthquake resistance of steel structures using rotational capacity limits

  • Pantousa, Daphne;Mistakidis, Euripidis
    • Earthquakes and Structures
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    • v.10 no.4
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    • pp.867-891
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    • 2016
  • This paper addresses numerically the behavior of steel structures under Fire-after-Earthquake (FAE) loading. The study is focused on a four-storey library building and takes into account the damage that is induced in structural members due to earthquake. The basic objective is the assessment of both the fire-behavior and the fire-resistance of the structure in the case where the structure is damaged due to earthquake. The combined FAE scenarios involve two different stages: during the first stage, the structure is subjected to the ground motion record, while in the second stage the fire occurs. Different time-acceleration records are examined, each scaled to multiple levels of the Peak Ground Acceleration (PGA) in order to represent more severe earthquakes with lower probability of occurrence. In order to study in a systematic manner the behavior of the structure for the various FAE scenarios, a two-dimensional beam finite element model is developed, using the non-linear finite element analysis code MSC-MARC. The fire resistance of the structure is determined using rotational limits based on the ductility of structural members that are subjected to fire. These limits are temperature dependent and take into account the level of the structural damage at the end of the earthquake and the effect of geometric initial imperfections of structural members.

Dynamic tensile behavior of SIFRCCs at high strain rates

  • Kim, Seungwon;Park, Cheolwoo;Kim, Dong Joo
    • Computers and Concrete
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    • v.26 no.3
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    • pp.275-283
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    • 2020
  • Reinforced concrete (RC) does not provide sufficient resistance against impacts and blast loads, and the brittle structure of RC fails to protect against fractures due to the lack of shock absorption. Investigations on improving its resistance against explosion and impact have been actively conducted on high-performance fiber-reinforced cementitious composites (HPFRCCs), such as fiber-reinforced concrete and ultra-high-performance concrete. For these HPFRCCs, however, tensile strength and toughness are still significantly lower compared to compressive strength due to their limited fiber volume fraction. Therefore, in this study, the tensile behavior of slurry-infiltrated fiber-reinforced cementitious composites (SIFRCCs), which can accommodate a large number of steel fibers, was analyzed under static and dynamic loading to improve the shortcomings of RC and to enhance its explosion and impact resistance. The fiber volume fractions of SIFRCCs were set to 4%, 5%, and 6%, and three strain rate levels (maximum strain rate: 250 s-1) were applied. As a result, the tensile strength exceeded 15 MPa under static load, and the dynamic tensile strength reached a maximum of 40 MPa. In addition, tensile characteristics, such as tensile strength, deformation capacity, and energy absorption capacity, were improved as the fiber volume fraction and strain rate increased.

A Study On The Reinforcing Effect Multibell Anchor Applied To The Cut Slope (비탈면에 적용된 다구근 앵커의 보강효과 연구)

  • Cha, Kyung-Sub;Kim, Seon-Ju;Kim, Tae-Hoon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.1286-1293
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    • 2010
  • The ground anchor used in domestic area, which resists by adhesion between anchor body and the ground to the external force, seems not to be adequate for soft ground and urban area where the boundary between structures is close because the ground is disturbed and lost its strength during boring. In order to overcome such a shortcoming an expanded anchor system has been developed. The ground expansion is accomplished by means of Pulse Discharge Technology. In this technology, a high voltage of electricity is stored and discharged in milliseconds which induces high pressure acting on the ground. By making a couple of bulbs, a passive resistance as well as shaft resistance are mobilized, and therefore a higher pullout resistance comparing existing ground anchors is developed.In this study, a couple of full scale tests were conducted in order to figure out how much the resistance of an expanded anchor increases comparing to the straight. As a result, it was found that a remarkable increase in ultimate pullout capacity is observed for the soft ground and as the number of bulb increases. In addtion, as a result of applying to a cut slope reinforcement, it appeared that the length of fixed zone of anchor can be reduced effectively.

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