• Journal of the Korean Geotechnical Society
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• v.34 no.4
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• pp.49-55
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• 2018

A pre-load of bracing was imposed to prevent the horizontal displacement on the strut of the braced wall adjacent to the building during the ground excavation. For this purpose, large scale model tests were conducted, without and with pre-load on braced wall. Adjacent building load was also imposed in different locations, that were 0 m, 1D, 2D on ground surface. In this study, model tests in 1:10 scale were performed in real construction sequences, and adjacent building was 12 m in width and the size of model test pit was 2 m in width, 6 m in height, and 4 m in length. As a result, it was found that the stability of the existing building adjacent to the braced wall within Rankine's active zone could be greatly enhanced when the horizontal displacement of the braced wall was reduced by applying a pre-load. which was larger than the designated axial force on the strut of the braced wall.

• The Journal of Engineering Geology
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• v.18 no.4
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• pp.433-437
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• 2008

It's essential to build an earth retaining structure at the beginning and end point of a tunnel constructed in a colluvium area. A large scale of colluvial soil may cause a problem to the stability of the excavation ground. An excavation in colluvium has different behavior characteristics from those in a sandy soil due to unstable elements and needs counter measures for it. There are few systematic research efforts on the behavior characteristics of an earth retaining structure installed in colluvial soil. Thus this study set out to collect measuring data from an excavation site at the tunnel pit mouth in colluvium and set quantitative criteria for the safety of an earth retaining structure. After comparing and analyzing the theoretical and empirical earth pressure from the measuring data, the lateral earth pressure distribution acted on the earth retaining wall was suggested.

• Journal of architectural history
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• v.32 no.3
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• pp.21-30
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• 2023

The Wolseong Wooden moat is a unique example. Which is a vertical wall made of wood. It shows a changing point how to make the wall by digging a hole and stacking stones vertically. This study tried to to make a assumption about the construction process of the wooden structure found in the Wolseong pit moat. I sorted out wooden elements and then analyzing these features and compared with the results of the excavation. After I made 3D modelling in the order to it was made. This moat is not only a function of digging up the ground to trap water, but also a technique of building structures to maintain walls. It is a valuable material that can show the woodworking engineering techniques of the Silla Dynasty.

• The Journal of Art Theory & Practice
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• no.14
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• pp.7-32
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• 2012

The exhibition was started in 2010 in the New Acropolis Museum of Athens and embarked a journey since 2011 as a travelling exhibition inside Greece and abroad. The main purpose of the exhibition was to draw attention of the general public to the value of the 'rescue excavation' and of cultural heritage of Greece, by presenting the reconstruction bust of a girl whose skull was found in Kerameikos cemetery of ancient Athens. The new Kerameikos excavation was initiated by the construction of Metropolitan Railway lines in the center of Athens between 1992 to 1998. It revealed a pit of a mass burial where about 150 people were inhumed in a very hasty way without proper funeral rites or offerings. These bodies are identified as the victims of the infamous plague of Athens in the first years of the Peloponnesian War(430-426 BC). The epidemic disease killed almost one third of the city population including Pericles, and brought extreme fear and panic to the Athens society. The traditional funerary rites were totally disrupted, and the social decorum and the morality among the citizens became enfeebled. The plague and the civil war were the decisive factors to end the Golden Age of Democratic Athens. However, the exhibition organizers did not focus on the tragic aspect of this disaster and its casualties. Their main concern was to simplify the scholarly works of archaeological excavation and microchemistry analysis so that the exhibition viewers will easily understand and empathize the living value of the scholarly works of ancient Greek civilization. The centripetal element of the exhibition was the vivid face of an 11 years old ancient girl 'Myrtis', which was carefully reconstructed based on both the scientific data and artistic imagination. Also the set up of the exhibition was structured in order to stimuli cognitive and emotional experience of the visitors who witnessed the rebirth of a vibrant human being from an ancient debris. The museologists' continuous efforts to promote projects of contemporary artists, publications, and school programs related to the exhibition indicate that the ulterior motive of this exhibition is the cultural education of the present and future generation through the intimate experiences of ancient Greek life. Also this is the reason why the various museums that held the travelling exhibition try to make the presentation as a gesture of memorial service for an anonymous Athenian girl who deceased circa 2400 years ago. The pragmatic efforts of Greek scholars and museologists through exhibition show us a way to find a solution to the continuous threat of cultural resources by massive construction projects and land development, and to overcome public indifference to the history and cultural heritage.

• Tunnel and Underground Space
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• v.20 no.5
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• pp.369-377
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• 2010

Applied to the braced wall in order to stabilize the adjacent tunnel. A pre-load of bracing was imposed to prevent the horizontal displacement of the braced wall during the ground excavation. For this purpose, real scale model tests were conducted, without and with pre-load on braced wall. Real scale model tests were conducted, without and with building load (0 m, 1D, 2D) on ground surface. As a result, it was found that the stability of the existing tunnel adjacent to the braced wall could be greatly enhanced when the horizontal displacement of the braced wall was reduced by applying a pre-load, which was larger than the designated axial force of bracing. In this paper, the behaviors of braced wall and adjacent tunnel was studied. Model tests in 1:10 scale were performed in real construction sequences. Adjacent tunnel was 12 m in diameter and the size of test pit was 2.0 m (width) ${\times}$ 6.0 m (height) ${\times}$ 4.0 m (length) in dimension.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.214-220
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• 2003

Pipe jacking is a name for a method to excavate a tunnel by pushing pipe into the ground from an especial pit. Size of tunnels in this method is different from under 900mm (microtunneling) to more than 3,000mm. Method of excavation is also different from hand digging to use of any kind of tunnel boring machines such as slurry and earth pressure balance (EPB) machines. Slurry pipe jacking was firmly established as a special method for the nondisruptive construction of the underground tunnels in urban area. During the pipe jacking and microtunneling process, the jacking load is an important parameter, controlling the pipe wall thickness, need to and location of intermediate jacking station, selection of jacking frame and lubrication requirements. The main component of the jacking load is due to frictional resistance. In this paper the skin friction between pipe surface and surrounding condition also lubricant quality based on a few fundamental tests, were considered. During this study unconfined compressive strength test, dynamic friction measurement test and direct shear box test were raised for one of the largest diameter slurry pipe jacking project in Fujisawa city in Japan. It could be concluded that in slurry pipe jacking, prediction of frictional forces are mainly dependent on successful lubrication, its quality and lubricant strength parameters. Conclusions from this study can be used for the same experiences.

• Journal of the Society of Disaster Information
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• v.4 no.2
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• pp.10-27
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• 2008

When the ground is excavated adjacent to the existing tunnel, which is loaded by the surcharge on the ground surface, the tunnel stability would be very sensitive to the deformation of the ground induced by the horizontal displacement of braced wall. The stability of the existing surcharged tunnel could be controlled by pre-loading on the braced wall. In this paper, it was investigated, if it would be possible to keep the existing surcharged tunnel stable by preventing the horizontal displacement of a braced wall by imposing the pre-loading during the ground excavation. For this purpose, large scale model tests were performed in a scale 1/10 at the test pit which was 2.0m in width and 6.0m in height and 4.0m in length. Isotropic test ground was constructed homogeneously by wet sand. Model tunnel was constructed in the test ground. Surcharge was loaded on the ground surface above the tunnel. During the tests, the behavior of model tunnel and model braced wall was measured. Numerical analyses were also performed in the same condition as the tests. And their results were compared to that of the model tests. Consequently, the effect of a surcharge could be compensated by imposing the pre-loading on the braced wall. The existing tunnel and the braced wall could be kept stable by preventing the horizontal displacement of the braced wall through pre-loading, although the tunnel is surcharged.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.1
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• pp.85-92
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• 2002

The calculation of earthwork plays a major role in plan or design of many civil engineering projects, and thus it has become very important to advanced the accuracy of earthwork calculation. Current methods used for estimating the volume of pit excavation assumes that the ground profile between the grid points is linear(trapezoidal rule), or nonlinear(simpson's formulas). Generally speaking, the nonlinear profile formulas provide better accuracy than the linear profile formulas. However, all the formulas mentioned have a common drawback to ground profile, such as sharp corners or the grid points of any two straight lines. In this paper, we propose an algorithm of finding a spline surface which interpolates the given data and an appropriate method to calculate the earthwork. We present some computational results showing that our proposed method provides better accuracy than Chen and Lin's method.

• Environmental Engineering Research
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• v.18 no.1
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• pp.37-43
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• 2013

Water distribution pipes installed underground have potential risks of pipe failure and burst. After years of use, pipe walls tend to be corroded due to aggressive soil environments where they are located. The present study aims to assess the degree of external corrosion of a distribution pipe network. In situ data obtained through test pit excavation and direct sampling are carefully collated and assessed. A statistical approach is useful to predict severity of pipe corrosion at present and in future. First, criteria functions defined by discriminant function analysis are formulated to judge whether the pipes are seriously corroded. Data utilized in the analyses are those related to soil property, i.e., soil resistivity, pH, water content, and chloride ion. Secondly, corrosion factors that significantly affect pipe wall pitting (vertical) and spread (horizontal) on the pipe surface are identified with a view to quantifying a degree of the pipe corrosion. Finally, a most reliable model represented in the form of a multiple regression equation is developed for this purpose. From these analyses, it can be concluded that our proposed model is effective to predict the severity and rate of pipe corrosion utilizing selected factors that reflect the fuzzy soil environment.

• Journal of the Korean GEO-environmental Society
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• v.13 no.10
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• pp.15-23
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• 2012

A numerical model and field monitoring data are used to estimate a change in groundwater level at a borrow site, which will be constructed at the mountainous area with a large ground excavation in the study area, Hwaseong city. Lithologic data and hydraulic coefficients are collected at 9 boreholes and also groundwater levels are measured at these boreholes and existing wells in the study area. Additionally, groundwater recharge rate for the type of land cover is estimated using water budget analysis; 133.34mm/year for a mountainous area, 157.68mm/year for a farming area, 71.08mm/year for an urbanized area, and 26.06mm/year for a bedrock exposure area. The change in groundwater level in and around a borrow site is simulated with Modflow using these data. The result of a transient model indicates that a removal of high ground (over 40El.m) by an excavation will produce a decrease in groundwater levels, up to 1 m, around a borrow site in 10 years. It also explains that this ground excavation will bring about the decreases of 9.4% and 7.0% for groundwater recharge and surface runoff, respectively, which are the factors causing groundwater level's change. This study shows that it is required to construct the groundwater monitoring wells to observe the change of groundwater near a borrow site.