• Journal of the Korean Geotechnical Society
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• v.24 no.7
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• pp.51-60
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• 2008

In this paper, the behaviour of shell foundation was studied. In the theoretical program, the general shallow foundation theories and failure mechanism developed by Terzaghi, Mayerhof and others were reviewed and compared. In the numerical study, the 2 and 3 dimensional FEM simulations were carried out using an uncoupled-analysis approach. The results obtained from the model test show that the bearing capacity of shell foundation was about 25% to 30% larger than that of general foundation. Due to the cases of shell angle, the maximum bearing capacity of shell foundation shows when the shell angle of foundation was $60^{\circ}$. In addition, even if the shell foundation has various advantages compared with the general foundations as described above, the practical verifications in full scale size will be necessary to use in the field and will be helpful in the technical development of other special foundations.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.107-118
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• 2009

As CPT penetration tends to show a similar behavior to that of pile driving, a number of methods for estimating the toe bearing capacity of piles based on CPT data have been proposed. To evaluate the applicability of the methods in this country, a total of 172 dynamic load tests data on PHC piles and 82 CPT data at a site in the Nakdong River estuary were collected. A specific four-step procedure was adopted for the selection of the reliable data, and statistical techniques were then applied to the analysis of the applicability. The results indicated that among a total of 10 CPT-based methods applied, the best one is the Aoki method (1975), followed by the LCPC (1982), ICP (2005) methods and others.

• Journal of the Korean Geotechnical Society
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• v.23 no.4
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• pp.47-58
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• 2007

The usage of Integral abutment bridges has been increased worldwide because of reducing bridge maintenance costs and resisting seismic loads. Although these attributes make the integral abutment bridge an increasingly popular choice, back-abutment interaction issues remain unresolved. Hence, the earth pressure behavior of an integral abutment bridge having 90 m long PSC beam bridge for the first time in Korea was analyzed by conducting long term monitoring in this study. Based on this study, the results were as follows; the ratio of maximum passive movement to the abutment height (H) of 0.0027 and the maximum passive earth pressure coefficient of 4.8 were developed at 0.82H from the bottom of the abutment during summer season. During winter season, the ratio of maximum active movement to H of 0.0011 and the maximum active earth pressure coefficient of 0.7 were developed at the same location as in summer season. The new earth pressure distributions having a trapezoid type were proposed based on this study.

• Journal of the Korean Geotechnical Society
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• v.24 no.9
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• pp.33-40
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• 2008

This paper describes the performance of ground improvement project using prefabricated vertical drains of condition, in which approximately 10m dredged fill overlies original soft foundation layer in the coastal area composed of soft marine clay with high water content and high compressibility. From field monitoring results, excessive ground settlement compared with predicted settlement in design stage developed during the following one year. In order to predict the final consolidation behavior, recalculation of consolidation settlements and back analysis using observed settlements were conducted. Field monitoring results of surface settlements were evaluated, and then corrected because large shear deformation occurred by construction events in the early stages of consolidation. To predict the consolidation behavior, material functions and in-situ conditions from laboratory consolidation test were re-analyzed. Using these results, height of additional embankment is estimated to satisfy residual settlement limit and maintain an adequate ground elevation. The recalculated time-settlement curve has been compared with field monitoring results after additional surcharge was applied. It might be used for verification of recalculated results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1D
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• pp.57-65
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• 2008

Joint of concrete pavement contributes to improvement of pavement performance by preventing occurrence of random cracking due to drying shrinkage and temperature changes of concrete slabs at early age. However, saw-cutting operations performed prior to sufficient concrete hardening develop micro-cracking of the concrete near the joints, which may develop to long-term distresses due to repetitious traffic and environmental loadings. To reduce the distresses, the joint crack inducers with heights of 100 mm, 150 mm, and 220 mm and the joint cracking slots with various depth were installed at a test section to investigate occurrence of the joint cracks and their behaviors over 5 months. As the results, higher efficiency of the crack inducing and larger behavior of the joint cracks were observed for the taller joint crack inducer. Higher efficiency of the crack inducing and improvement of the joint performance are warranted by additional investigation and reformation of the joint crack inducer.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4A
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• pp.581-590
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• 2008

The panels are used as a composite part of the completed deck. They replace the main bottom transverse deck reinforcement and also serve as a form surface for the cast-in-place concrete upper layer that contains the top of deck reinforcement. In this paper, three types of the detail for joints was selected and their structural performance in terms of strength and crack contral was investigated through static tests on composite beams. Form the results, the validity of loop joints for continuity of half-depth precast deck was observed and especially an overlapping length of loop joint and transverse reinforcement were checked. The results suggest that increasing the loop overlapping length increases the flexural strength of half-depth precast deck with loop joints. In terms of crack contral, the loop joint with transverse reinforcement showed better performance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.271-278
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• 2010

Semi rigid pavement is a pavement type using advantages of both flexibility of asphalt pavement and rigidity of concrete pavement by infiltrating cement paste into voids of open graded asphalt mixtures. The semi rigid pavement has better smoothness and smaller driving vibration or noise comparing to the concrete pavement, and has smaller permanent deformation and has temperature falling effect comparing to the asphalt pavement. The temperature falling effect were investigated at a semi rigid overlay pavement test section, and the temperature falling and water retaining effects were verified by measuring the temperature and weight of specimens at a housetop. Horizontal and vertical stresses and strains were compared by structural analysis of the semi rigid pavement and asphalt pavement using the Abaquser o, a commercial 3D finite element analysis program. The results were verified by Bisar 3.0, a multi-layered elastic analysis program. Performance of the semi rigid pavement and asphalt pavement were compared by predicting fatigue cracking based on the structural analysis results.

• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.557-562
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• 2023

This study reviewed the use of soil injection materials using circulating resources as injection materials for the steel pipe multi-stage construction method. The tests performed were homogel time and homogel compressive strength. The steel pipe multi-stage construction method is an auxiliary construction method for tunnels, and the expression of initial strength after construction is an important factor. The better the strength development in the initial stage, the more it can be used as an injection material suitable for the multi-stage steel pipe construction method. As a result of laboratory test, it was found that the homogel time of the injection material using circulating resources required more time than the mixing ratio using cement as the injection material. In addition, it was found that the initial strength curing time satisfying 2MPa was required for more than 24 hours. Therefore, it was confirmed that the injection material using recycled resources required a longer initial curing time than cement of the same mixing ratio.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.851-863
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• 2023

The mandatory use of BIM(Building Information Model) in larger Korean public construction projects necessitates participants to have a comprehensive understanding of the relevant procedures and technologies, especially during the bidding stage. However, most small and medium-sized construction and engineering companies possess limited BIM proficiency and understanding. This hampers their ability to recognize bidding requirements and make informed decisions. To address this challenge, our study introduces a method to gauge the complexity of BIM requirements in bidding documents. This is achieved by integrating a morphological analyzer, which encompasses BIM bidding terminology, with a deep learning model. We investigated the effects of the parameters in our proposed deep learning model and examined its predictive validity. The results revealed an F1-score of 0.83 for the test data, indicating that the model's predictions align closely with the actual BIM performance challenges.

• Explosives and Blasting
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• v.42 no.1
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• pp.1-11
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• 2024

Through existing research and construction cases during tunnel blasting, the electronic blasting method is reported to be more effective in reducing blast vibration than the normal blasting method. However, due to the high price of electronic detonators, they are only used in some blasting sites where security objects are located nearby. Accordingly, this study performed tunnel blasting tests by adjusting the ratio of electronic and non-electronic detonators. And through the research results, the reduction effect of blasting vibration according to the detonator ratio was evaluated. The research results showed that the reduction effect of blast vibration was greatest when 100% electronic detonator was applied. In addition, when more than 52% of the electronic detonator was applied, it was found that the reduction effect was similar to the reduction effect when 100% of the detonator was used.