• 건축구조
• /
• 제14권4호
• /
• pp.79-86
• /
• 2007

Underground space development is more active on the latest date. Currently, we construct an connecting tunnel Euljiro underground shopping-area in seoul. we select DSM, considering geological condition and construction efficiency. The numerical analysis is performed with PENTAGON-3D and MIDAS CIVIL This paper will introduce the Earth Tunnel Method and make an examination possible to apply downtown weak ground.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2004년도 춘계학술발표회
• /
• pp.327-333
• /
• 2004

Corestone ground mass has complicated characteristics as it is made up of hard and stiff corestone in a relatively weak and soft matrix. Model corestone ground mass which is physically identical with the stiff corestone in weak matrix were tested in uniaxial compression. The tests show that the increase of the corestone proportion brought the gradual increase of the elastic modulus as well. The ground mass was weaker when the corestone proportion was low while it was stronger in higher corestone proportion. The size of the corestone had no influence on the strength and elastic modulus as long as the proportion of the corestone remains same.

• 한국환경복원기술학회지
• /
• 제7권1호
• /
• pp.68-76
• /
• 2004

Corestone ground mass has complicated characteristics as it is made up of hard and stiff corestone in a relatively weak and soft matrix. Model corestone ground mass whichis physically identical with the stiff corestone in weak matrix were tested in uniaxial compression. The tests showthat the increase of the corestone proportion brought the gradual increase of the elastic modulus as well. The ground mass was weaker when the corestone proportion was low while it was stronger in higher corestone proportion. The size of the corestone had no influence on the strength and elastic modulus as long as the proportion of the corestone remains same.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
• /
• pp.584-590
• /
• 2009

One of the critical design problems involved in deep tunnelling in brittle rock, is the creation of surface spalling damage and breakouts. If weak fault zone is developed in deep tunnel, squeezing problem is added to the problems. According to the results of ground investigation in the study area, hard granitic rockmass and distinguished high angle fault zone are distributed on the tunnel level over 400m depth. To analyse the probability of brittle failure and squeezing, ground characterization with special lab. and field test were carried out. By the results, probability of brittle failures like spalling and rock burst is very low. But squeezing may be probable, if weak fault zone observed surface and drill core is extended to designed tunnel level.

• ETRI Journal
• /
• 제44권2호
• /
• pp.339-345
• /
• 2022

This article presents an investigation of the effects on a grounding system of wireless power transfer (WPT) when transmitting over relatively far distances, that is, up to 1.25 m. Conventional two-coil WPT systems are sufficiently commercialized in strong coupling range, but it is important to accomplish the long-range WPT in weak coupling range for further various applications. This system depends on the coupling effect between the two coils that the grounds of the transmitting and receiving coils should be completely separated. However, when evaluating the performance of two-coil systems with the instrument consisting of two ports and one common ground, undesirable problems occur in weak coupling ranges, for example, obtaining disagreeable transmission efficiency and degrading system stability/reliability. We investigate the problems of the leakage power from common ground systems and provide a practical solution to obtain a reliable WPT system by using an isolation transformer. The usefulness of this approach is that it is possible to achieve the stability of the system with relatively far transmitting distances and to determine the exact transmission efficiency.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 1992년도 가을학술발표회 논문집
• /
• pp.145-148
• /
• 1992

This paper reports the application of field tests to weak ground. In this study, field and laboratory tests were performed in the west seashore of KOREA(Ildo, Sore, Kunsan, Youngam). Applied tests are standard penetration test, cone penetration test, dilatometer test, field vane test, unconsolidated undrained test, oedometer test and other fundametal material properties tests. The results of in-situ test are used to estimate soil types and undrained shear strengths of five clay local deposits. SPT results showed low reliability and FVT war also demonstrated the best field test to weak clayey deposits.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
• /
• pp.1334-1337
• /
• 2009

A SMART anchor is a kind of friction mount anchor, the load is diffused and applied to the various parts of the distributed bond length, having less impact on the grout strength, and being able to secure necessary anchoring force in relatively soft grounds. Smart anchor can have strong loads in soft and weak grounds as in rock beds.

• 한국방재학회:학술대회논문집
• /
• 한국방재학회 2008년도 정기총회 및 학술발표대회
• /
• pp.71-74
• /
• 2008

For reinforcing the overturn of concrete pole instituted in slope ground and weak ground, in this paper, develop the reinforcing installation. The installation increase penetration depth and effect of increasing the penetration depth is verified by experimental paper of Lim, jong suk(2004). In this research, through the experiment of bending test using the reinforcing installation, evaluate the performance. In the result of experiment, concrete pole behave elastically in design load and all sample are safe up to failure load.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
• /
• pp.1170-1180
• /
• 2009

Recently this country has carried out the coast reclamation centering on the west and south coast for effective practical use of a country, considering purchase of materials and environmental problem, most reclaiming work is processing to spoil reclamation which is easy to secure the amount of materials. In case of weak ground that is formed by spoil reclamation like this, initial moisture content is high, as slurry state that is rarely revealed ground strength, compressibility and water permeability have been shown nonlinear change by compaction progress. Analysis of weak ground is unreasonable because the existing Terzaghi compaction theory analyzes compaction fixed number to regular invariable number for prediction of compaction state. This study computes the relation with void ratio-effective pressure and void ratio-finite transformation which is the most basic matter to predict finite strain compaction state of the south coast spoil, and analyze the basic feature to predict compaction feature of the south coast spoil reclaimed ground.

• Structural Engineering and Mechanics
• /
• 제76권3호
• /
• pp.421-433
• /
• 2020

Masonry infills are normally considered as non-structural elements in design practice, therefore, the interaction between the bounding frame and the strength contribution of masonry infills is commonly ignored in the seismic analysis work of the RC frames. However, a number of typical RC frames with irregular distributed masonry infills have suffered from undesirable weak-story failure in major earthquakes, which indicates that ignoring the influence of masonry infills may cause great seismic collapse risk of RC frames. This paper presented the investigation on the risk of seismic collapse of RC frames with irregularly distributed masonry infills through a large number of nonlinear time history analyses (NTHAs). Based on the results of NTHAs, seismic fragility curves were developed for RC frames with various distribution patterns of masonry infills. It was found that the existence of masonry infills generally reduces the collapse risk of the RC frames under both frequent happened and very strong earthquakes, however, the severe irregular distribution of masonry infills, such as open ground story scenario, results in great risk of forming a weak story failure. The strong-column weak-beam (SCWB) ratio has been widely adopted in major seismic design codes to control the potential of weak story failures, where a SCWB ratio value about 1.2 is generally accepted as the lower limit. In this study, the effect of SCWB ratio on inter-story drift distribution was also parametrically investigated. It showed that improving the SCWB ratio of the RC frames with irregularly distributed masonry infills can reduce inter-story drift concentration index under earthquakes, therefore, prevent weak story failures. To achieve the same drift concentration index limit of the bare RC frame with SCWB ratio of about 1.2, which is specified in ACI318-14, the SCWB ratio of masonry-infilled RC frames should be no less than 1.5. For the open ground story scenario, this value can be as high as 1.8.