• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.149-156
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• 2002

Field measurements were carried out in this study to investigate the behavior of cut and cover tunnel such as the distribution and the magnitude of the earth pressure during back fill process of the ground material. Three kinds of measuring instruments, such as the earth pressure load cell, the concrete strain gauge and the reinforcing bar meter of embedded type in concrete structure were installed and measured. Earth pressure load cells, installed after construction of the tunnel lining, measure the outside forces acting on the tunnel lining with radial directions. Three load cells were installed at the crown, the right and the left shoulder of the tunnel, respectively. Three sets of reinforcing bar meter were installed in the double reinforcements of the tunnel lining and their locations were the same with the position of the earth pressure load cells. Concrete strain gauge was installed only one site of the upper compressive part at the tunnel crown. Based on the measuring results in the field, the deformation and the earth pressure acting on the tunnel lining were investigated with the back fill process of the ground material. Considerations on the validity of the measuring results were paid. For the analysis of measurements, after dividing back fill process into three steps, various factors which affect on the behavior of tunnel lining were investigated at each step.

• Geomechanics and Engineering
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• v.29 no.3
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• pp.339-348
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• 2022

The bored tunneling method is generally preferred for urban tunnel construction, However the cut & cover tunnel is still necessary for special conditions, such as metro station and access structures. In some case, deep excavation for cut & cover construction is planed of irregular and unusual shape, as a consequence, the convex and concave corner is often encountered during that excavation. In particular, discontinuity or imbalance of the support structure in the convex corner can lead to collapse, which may result in damages and casualties. In this study, the behavior of the convex corner of retaining structure were investigated using 3-dimensional numerical models established to be able to simulate the split-shaped behavior of convex corners. To improve the stability in the vicinity of the convex corner, several stabilizing measures were proposed and estimated numerically. It is found that linking two discretized wales at the convex corner can effectively perform the control of deformation. Furthermore, it was also confirmed that the stabilizing measures can be enhanced when the tie-material linking two discretized wales is installed at the depth of the maximum wall deflection.

• Journal of Korean Tunnelling and Underground Space Association
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• v.7 no.2
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• pp.177-186
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• 2005

World widely, the occurrences of earthquakes have been increased recently including to nations which earthquake often happen to like Japan. Taking into account that the earthquake acceleration at design was 0.154 g at the contigency level earthuake (CLE) with its geological condition, it resulted that this method must be the most efficient condition against the earthquake vibration to two lane cut-and cover tunnel. The correlations between the result of the shaking table test and its numerical analysis showed that the test data of the bending stress due to the earthquake vibration have been underestimated about 5 percents in case of the cut slope 1 : 0.6 and about 10 percent in case of the cut slope 1 : 1.2. However, on average, the results showed a similar tendency that the higher the height of the backfill of the EPS block was, the less the bending stress was.

• Journal of the Korean Geotechnical Society
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• v.22 no.6
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• pp.27-40
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• 2006

Damage of cut-and-cover tunnel lining can be attributed to physical and mechanical factors. Physical factors include material property, reinforcement corrosion, etc. while mechanical factors include underground water pressure, vehicle loads, etc. This study is limited to the modeling of rigid circular cut and cover tunnel constructed at a depth of $1.0{\sim}1.5D$ in loose sandy ground and subjected to a vibration frequency of 100 Hz. In this study, only damages due to mechanical factors in the form of additional loads were considered. Among the different types of additional, excessive earth pressure acting on the cut-and-cover tunnel lining is considered as one of the major factors that induce deformation and damage of tunnels after the construction is completed. Excessive earth pressure may be attributed to insufficient compaction, consolidation due to self-weight of backfill soil, precipitation and vibration caused by traffic. Laboratory tunnel model tests were performed in order to determine the earth pressure acting on the tunnel lining and to investigate the applicability of existing earth pressure formulas. Based on the difference in the monitored and computed earth pressure, a factor of safety was recommended. Soil deformation mechanism around the tunnel was also presented using the picture analysis method.

• Management Science and Financial Engineering
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• v.14 no.1
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• pp.91-96
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• 2008

Robust knapsack problem appears when dealing with data uncertainty on the knapsack constraint. This note presents a generalization of the cover inequality for the problem with its lifting procedure. Specifically, we show that the lifting can be done in a polynomial time as in the usual knapsack problem. The results can serve as a building block in devising an efficient branch-and-cut algorithm for the general robust (0, 1) IP problem.

• 한국터널공학회:학술대회논문집
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• 2005.04a
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• pp.233-247
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• 2005

Most tunnel lining material which has been used in the domestic is a concrete. But many problems as the construction period, the cost, and the crack occurrence for the design, construction, and management were happened in the concrete lining. For this reason, many research institutes like the Korea Highway Corporation recognize the necessity of an alternate material development and grow on the interest for that. So in this study, the seismic behaviour characteristics for the application of the Corrugated Steel Plate Lining in cut-and-cover tunnel are evaluated as several conditions for the backfill height, the cutting slope, and the relative density of backfill soil are changed. The compressive stress which is calculated in the Corrugated Steel Plate Lining by the seismic load is decreased as the backfill height increases and the cut slope grows gentle. Also, the moment shows the tendency of decrease according to the increase of the backfill height. But in the case of the relative density of the backfill soil is small, the moment increases according to the increase of the backfill height and affects the dynamic behaviour characteristic. So it is considered that the relative density of the backfill soil is also the important point. As the result in analyzing the seismic response characteristics of the reinforcement spacing of the Corrugated Steel Plate, the variation in the compressive force is hardly happened, but the moment and the shear force increase on the reinforcement spacing being narrow.

• Computers and Concrete
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• v.17 no.4
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• pp.435-453
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• 2016

The main purpose of this study is to perform optimum cost design of cut and cover RC shallow tunnels using Artificial bee colony and genetic algorithms. For this purpose, mathematical expressions of objective function, design variables and constraints for the design of cut and cover RC shallow tunnels were determined. By using these expressions, optimum cost design of the Trabzon Kalekapisi junction underpass tunnel was carried out by using the cited algorithms. The results obtained from the algorithms were compared with the results obtained from traditional design and remarkable saving from the cost of the tunnel was achieved.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.957-964
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• 2004

The selected structure for the value engineering review is one section of cut and cover tunnel for Seoul Subway Line 9. The primary focus of the review is on the optimisation of the structures to save cost on the existing Line 9 contracts through variation of the design criteria as it affects the permanent works. This is to be achieved through comparison with design criteria for other selected international subways. Criteria resulting from the review must not compromise public safety and durability for the 100 year design life.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.9
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• pp.745-752
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• 1990

This paper deals with the path sensitization algrithm from PI to PO center on the nodes of high testability mainstay when CUT is tested by pseudo exhaustive testing. In CUT, the node definition of high testability mainstay treats the testability values of the entire nodes with the population composed of the raw data, and after we examined the level of significance(1-a) region, we accomplished in the estimation of the confidence interval of the testability. Focusing on the defined nodes of high testability mainstay, we performed the singular cover and consistency operation to the forward and backward logic gates. Thus, we easily generated the pseudo exhausitve test patterns. As a result, (1-a) region has 0.1579 and the pseudo exhaustive test patterns are least generated and the rate of test pattern is 1.22%, compared with exhaustive testing. (1-a) region has 0.2368 and this results exhibits the optimal performance of the singular cover and consistency operation. Applying the generated pseudo exhaustive test patterns to the stuck-at faults existing on the inputs and internal nodes in CUT, we verified this performance on the output. Thus, it is confirmed that functional testing of the proposed path sensitization algorithm is very useful.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.11
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• pp.1586-1597
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• 2007

This study is an attempt to examine fashion elements appearing in the cover-page design of fashion magazines published in Korea and aims to find Korea#s own fashion identity in fashion styling and designing of those fashion magazines. In order to do so, the study reviewed the related literature and analyzed the issues of Vogue and Harper#s Bazaar magazines published between 2004 and 2006. The results of the study can be summarized as follows: In case of fashion photographs, the largest number of 72 sampled cover-model photographs is in approximately three-quarter cut size. For the items, most take the form of one-piece dress and feature the use of a variety of accessories. In case of dresses, most are the creations of foreign designers and famous fashion models or celebrities show up, mostly alone, as features on the cover pages. Because of the nature of fashion magazines, their primary emphasis is put on the dress among other things, but on the other hand some of those magazines have differential cover pages where the model#s face is highlighted with the look of makeup or a famous female actress stands out. However, the fashion in designing the cover pages of magazines is, rather than to show the dress itself, to create a new combination of different elements as total fashion or convey an image based on such a fashion style.