http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
터널 시공현장 붕괴 사례를 이용한 막장의 안정성 평가 연구
김민태(Kim, Mintae) 한국지반공학회 2024 한국지반공학회논문집 Vol.40 No.2
쉴드공법은 국제적인 사례에서 그 안정성을 입증한 반면, 경제적 효율성을 지닌 것으로 알려진 NATM 터널 굴착공법은 피복이 얕고 지반이 풍화되며 지하수가 많은 도심지에 적용 시 어려움을 겪고 있다. 본 논문에서는 도심지의 풍화된 암반층과 미고결 사질토 지반에서 발생할 수 있는 전형적인 두 가지 붕락 사례를 소개하고, 여섯 가지 안정성 평가 방법으로 두 붕락 사례를 분석하였으며, 그 결과를 종합하여 육각형의 다이어그램에 의한 방법으로 터널의 막장 안정성을 평가하였다. 본 연구의 분석 결과, 붕괴한 두 터널 현장의 결과와 평가 결과가 잘 일치하였으며, 대상터널의 지반 특성을 고려한 종합적인 평가 방법인 막장 안정성 평가 다이어그램에 의한 방법은 터널 설계 단계에서 터널의 막장 안정성을 확보하는 데 중요한 역할을 할 것으로 판단된다. While shield tunneling has demonstrated stability in international cases, the new Austrian tunneling method (NATM) encounters challenges in urban environments with shallow cover, weathered ground, and high groundwater levels. This paper introduces two typical collapse scenarios observed in urban areas, specifically within weathered bedrock and uncemented sandy soil layers. The collapses are analyzed using six stability evaluation methods, and the results are synthesized to assess the excavation face stability through a hexagonal diagram. The study finds a consistent agreement between the analysis results of the two collapsed tunnel sites and the evaluation outcomes. The employment of the stability evaluation diagram, a comprehensive method that considers the ground characteristics of the target tunnel, proves crucial for ensuring barrier stability during the tunnel design stage. This method is essential for a holistic evaluation, especially when addressing challenging ground conditions in urban settings.
김민태(Mintae Kim),오성업(Sungup Oh),성세진(Sejin Seong),백동기(Tongki Paek) 전력전자학회 1998 전력전자학술대회 논문집 Vol.- No.-
Many Harmonics components is contained within the stator currents of the High-speed Reluctance Synchronous Motor with salient pole rotor. They cause the power factor of RSM to get worse. In this paper, the mathematical model of RSM is investigated. And SV_PWM control method is applied to reduce Harmonics components in the stator currents. Simulation results shows the fast response of speed and the reduction of Harmonics components at steady state.<br/> <br/>
김민태(MinTae Kim),제성욱(Sung Uk Je),이해성(Hae Sung Lee),주종남(Chong Nam Chu) Korean Society for Precision Engineering 2006 한국정밀공학회지 Vol.23 No.12
In this work, the surface integrity smoothened with a ball end mill was investigated. Because surface integrity mainly affects the manual finishing process, RV<SUB>AM</SUB> (Remaining Volume After Machining) was introduced, and it gives the relation between machining process and finishing process. Runout and phase shift which adversely affect surface integrity were considered in the generation of surface topography. Cutting points in ball end milling were identified with positional vectors and a set of vectors which have the minimum height in unit area was selected for the generation of surface and RV<SUB>AM</SUB> RV<SUB>AM</SUB> variation according to runout and phase shift was calculated and experimentally verified in proposed HSM conditions for mold machining. From the simulations and the experiments, a desirable High Speed Machining condition was suggested.
가속도 센서 기반 지능형 타이어를 이용한 타이어 마모 추정
김승택(Seungtaek Kim),정다솔(Dasol Jeong),최세범(Seibum Choi),이호종(Hojong Lee),김민태(Mintae Kim) 한국자동차공학회 2020 한국자동차공학회 지부 학술대회 논문집 Vol.2020 No.6
In this paper, intelligent tire based tire wear estimation method is proposed. It is important to estimate tire wear because tire wear is closely related to vehicle safety, especially braking distance. The existing method of estimating tire wear is considering mileage and tire wear rate. However, this method has the limitation that the estimation of the tire wear rate should be preceded. Therefore, in this paper, tire wear estimation method using intelligent tires is proposed. Three wear parameters predominant to wear that can be obtained from an intelligent tire acceleration sensor are proposed: x-direction acceleration peak, z-direction acceleration peak, and z-direction jerk peak. Tendency between the corresponding factor and wear was confirmed through an indoor test. The effect of tire load, speed, and pressure on the wear factor was considered and tire wear was estimated using the support vector regression technique. Wear estimation performance was verified by indoor testing.
박민수(Minsoo Park),김민태(Mintae Kim),이해성(Haesung Lee),주종남(Chongnam Chu) Korean Society for Precision Engineering 2004 한국정밀공학회지 Vol.21 No.10
Finishing is the final process in molds manufacturing and consumes much process time. Also, it influences on surface quality of molds. But, there are few systematic methods to control the process. In this work, basic experiments were carried out to study the machining characteristics of the finishing tools. From the experiments, critical surface roughness and wear coefficient are suggested to reduce the number of finishing steps and to plan a systematic finishing procedure. Comparison experiments were carried out between the expert's method and the new method, which is based on the results of this research. From the experiments, it is verified that the systematic method takes less time and generates less form error in the machined surface than the worker's method.