• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.482-489
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• 2009

Various model piles with different sections such as reinforced concrete, steel, steel-concrete composite without rebar and steel-concrete composite with rebar were made, and vertical load test was conducted using a large scaled UTM(Universal Test Machine) to evaluate Young's modulus and ultimate load of the model piles. Based on the tests, ultimate load of steel-concrete composite pile is 31% greater than the sum of it of reinforced concrete pile and it of steel pile. This is caused that ultimate load and Young's modulus of inner concrete increase due to confining effect by outer steel casing. Variation of ultimate load is also insignificant depending on the ratio of length to diameter(L/D), therefore bucking has not an effect on change of ultimate load in case of the L/D below 10.

• Geomechanics and Engineering
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• 제7권1호
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• pp.37-53
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• 2014

A Web-based pile load test (WBPLT) system was developed and implemented in this study. Object-oriented and concept-based software design techniques were adopted to integrate the pile load test database into the system. A total of 673 case histories of pile load test were included in the database. The data consisted of drilled shaft and driven precast concrete pile axial load tests in drained, undrained, and gravel loading conditions as well as pre-analyzed data and back-calculated design parameters. Unified modeling language, a standard software design tool, was utilized to design the WBPLT system architecture with five major concept-based components. These components provide the static structure and dynamic behavior of system message flows in a visualized manner. The open-source Apache Web server is the building block of the WBPLT system, and PHP Web programming language implements the operation of the WBPLT components, particularly the automatic translation of user query into structured query language. A simple search and inexpensive query can be implemented through the Internet browser. The pile load test database is helpful, and data can be easily retrieved and utilized worldwide for research and advanced applications.

• Journal of Advanced Marine Engineering and Technology
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• 제38권4호
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• pp.403-408
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• 2014

조선소에서 건조하고 있는 선박, 해양플랜트에 설치된 발전기의 부하 성능 시험 시 생산되는 막대한 양의 전력은 컨테이너 형태로 제작된 로드뱅크를 통해 전량 열로 낭비된다. 따라서 본 연구에서는 선박 건조 시 발전기 부하시험으로 낭비되는 전력량을 대형 조선소를 대상으로 정량적으로 조사하였으며, 소형발전기에서 생산된 전력을 한전계통에 연계하여 회수하는 실험실의 실험결과를 바탕으로 조선소에서 발전기 부하시험 시 생산되는 전력을 한전계통에 연결할 경우 회수 가능한 전력량을 연구 분석하였다.

• Geomechanics and Engineering
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• 제29권4호
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• pp.407-420
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• 2022

Embedded piles, which are typically used in Korea, are precast piles inserted into prebored ground with cement paste. Dynamic pile tests tend to underestimate the bearing capacity of embedded piles because of the undeveloped shaft resistance prior to the curing of the cement paste and the insufficient energy transferred after the curing. In this study, a resistance combination method using the base resistance before the cement paste is cured and the shaft resistance after the cement paste is cured is proposed to obtain a combined load-settlement curve from dynamic pile tests. Two pairs of embedded piles with diameters of 600 and 500 mm are installed. Each pair comprises one pile for the dynamic pile test and another pile for the static load test. The shape of the load-settlement curve obtained using the proposed method is similar to that obtained from the static load test. Thus, the resistances evaluated using the proposed method at selected settlements are similar to those obtained from the static load test. This study shows that the resistance combination method may be used effectively in dynamic pile tests to accurately evaluate the bearing capacity of embedded piles.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1997년도 가을 학술발표회 논문집
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• pp.357-364
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• 1997

• 한국철도학회논문집
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• 제13권4호
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• pp.363-370
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• 2010

본 논문은 철도차량용 추진제어장치의 성능평가를 위한 관성부하 시험설비의 구조안전성 및 동특성 평가를 연구하였다. 추진제어장치는 철도차량의 핵심 부품으로서 차량에 적용하기 전에 안정성 및 신뢰성 검증이 충분히 이루어 져야 한다. 따라서 추진제어장치의 성능시험을 위한 관성부하 시험설비를 이론식을 바탕으로 하여 설계하였다. 설계된 관성부하 시험설비에 대해 Ansys v11.0을 이용하여 구조해석을 수행하였으며, ADAMS를 통해 동특성을 평가하였다. 관성부하 시험설비의 구조안전성은 조합하중하의 베어링에서 안전계수가 10.2로 만족하였다. 또한, 동적 시뮬레이션에 따른 플라이휠은 0.83mm이내의 최대진폭변위로 구조적 안정성이 확보되었다.

• 콘크리트학회논문집
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• 제11권5호
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• pp.119-130
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• 1999

Recently, as the building structure has been larger, higher, longer and more specialized, the demand of material with high-strength concrete for building has been increasing. In this research, silica-fume was used as an admixture in order to get a high-strength concrete. From the test result, High-strength concrete with cylinder strength of 1,200kgf/$\textrm{cm}^2$ in 28-days was produced and tested. The static test was carried out to measure the ultimate load, the initial load of flexural and diagonal cracking, crack patterns and fracture modes. The load versus strain and load versus deflection relations were obtained from the static test. The relation of cycle loading to deflections on the mid-span, the crack propagation and the modes of failure according to cycle number, fatigue life and S-N curve were observed through the fatigue test. Based on the fatigue test results, high-strength reinforced concrete beams failed to 57~66 percent of the static ultimate strength. Fatigue strength about two million cycles from S-N curves was certified by 60 percent of static ultimate strength.

• 한국신뢰성학회지:신뢰성응용연구
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• 제12권3호
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• pp.201-213
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• 2012

A gear type lubrication pump is an essential component of the powertrain and has a major role for supplying oil to the gears and bearings in automatic transmission with a hydraulic clutch. Therefore, the durability test code design of lubrication pump is very important to ensure the reliability of the entire transmission and the vehicle. In this study, the design process for the life testing of lubrication pump has been generalized by four steps. The four design steps of the life testing of lubrication pump consist of the configuration of load spectrum, rain flow counting and analysis of load level, the equivalent damage assessment and test code generation. In fact, the load spectrum should be obtained from the field operating condition but that kind of data is the top secret of manufacturers. This is not open to the public in general. So we could use the artificially simulated load spectrum instead of field obtained one and focused on the development of the general process for designing the life test of a gear type lubrication pump. Reliability goals for lubrication pump, pressure, torque, temperature and load spectrum, if present, as appropriate for the given test conditions, accelerated life testing for the lubrication pump can be designed by the developed design steps.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.700-705
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• 2003

The object of this study is to ensure the stability of flat freight cars using vibration performance test and static load test of body structures. We examined the flat car though static load test and dynamic characteristics analysis related traveling stability and vibration performance. In the results of static load test of body structures for flat car, all structures satisfied allowable stress of materials. The vibration performance test was satisfied with allowable standards. Although flat car exceed speed a little at some speed interval, it was estimated that the cause was not cars but rail.

• 한국지반공학회논문집
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• 제28권4호
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• pp.5-21
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• 2012

국내의 경우 종래의 말뚝기초의 설계에서는 주로 선단지지력에만 의존하는 설계가 이루어져 왔으나 현장에서 실제 크기 말뚝에 대한 하중전이측정실험이 이루어진 이후 많은 하중전이측정실험 자료들을 통하여 마찰력이 크게 발휘되는 것이 밝혀져 왔다. 본 연구에서는 항타강관말뚝 및 대구경 현장타설말뚝의 재하시험 시 측정된 축하중전이 사례들을 분석하여 재하시험방법에 따른 말뚝기초의 하중지지양상을 구명하였다. 사례 말뚝들의 평균마찰력 분담율을 말뚝의 종류, 재하시험방법, 상대근입길이, 말뚝의 직경, 지반의 종류 등의 함수로 상관관계를 나타내는 것은 곤란하였다. 평균 마찰력 분담율은 50% 이상을 상회하는 것으로 나타나고 있었으므로 사례 말뚝기초는 대체로 마찰지지말뚝으로 거동하는 경우가 많은 것을 볼 수 있었으며 극히 일부 사례말뚝은 혼합지지말뚝으로 거동하였다.