• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.731-736
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• 2001

In this thesis, the study on controlling of cracks of concrete box culvert in early ages is presented. The optimum construction method and economical analysis were proposed also through the experiment of the material and field test. As a result of the experiment of the material, using fly ash, CSA expansive agent and BELITE cement(type IV) showed good result in the control of cracks induced by heat of hydration and shrinkage. As a result of construction test analysis, the maintenance time of form system did not show a big difference in controlling of cracks. Control of distribution of reinforcement, spacing of expansion joint and use of BELITE cement showed big differences in the control of cracks in early ages. As a result of economical analysis, control of construction variables before construction can make it possible to reduce the repair expense.

• Journal of Ocean Engineering and Technology
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• v.34 no.2
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• pp.136-146
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• 2020

In this study, numerical simulations are used to analyze the effect of the south breakwater and weir on seawater flow change and circulation within the Gamcheon port. Flow patterns in the eastern direction are particularly affected by the breakwater during the ebb tide and current velocity is slightly reduced by construction of the weir. Additionally, seawater circulation is reduced by both features. In order to increase seawater circulation, a seawater flux structure is needed on the west breakwater. A weir-type structure will be more efficient than a seawater flux culvert.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.211-218
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• 2001

There are numerous factors in designing the civil-structure even for simple ones. So the designer has to be decide for such conditions and this makes him difficult. Recently, some design programs are used for the design of civil-structure. But even for using the existing design programs, another program is necessary, such as a finite element analysis program. Moreover a few errors may be made in the drafts which must be coincided with the structural calculations. In this study, the design programs for rahmen bridge with single span and box culvert were developed to reduce the design efforts and the manmade errors. These two design programs perform structural analysis, calculations, and making report and draft at a time. In addition, These programs suggest manuals according to standard specifications and references for design. When these programs are used for design, it will be able to reduce the efforts and time of civil engineers.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.06a
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• pp.21-31
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• 2001

The last 30 years have been significant worldwide growth in the use of EPS as a lightweight fill material. A new construction method was introduced, which reduces earth pressure acting on culvert and conduit by placing a thin layer of EPS. This paper analyzes the compressible inclusion function of EPS and geogrid which can results in reduction of earth pressure by arching that is the behaviour of soil-structure system involving redistribution of soil stress around the structure. Field test was conducted to evaluate the reduction of vertical earth pressure using EPS and geogrid inclusion. Based on field test it is found that the magnitude of reduced vertical earth pressure was about 24~50% compared to conventional method.

• Computers and Concrete
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• v.30 no.6
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• pp.409-419
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• 2022

The purpose of this study is to examine the effectiveness of biological repairing mortars on restoring the structural performance of a sewage culvert deteriorated by sulfate attack. The biological mortars were developed for protecting concrete structures exposed to sulfate attack based on the block membrane action of the bacterial glycocalyx. The diffusion coefficient of sulfate ions in the biological mortars was determined from the natural diffusion cell tests. The effect of sulfate-attack-induced concrete deterioration on the structural performance of culverts was examined by using the moment-curvature relationship predicted based on the nonlinear section lamina approach considering the sulfuric-acid-induced degradation of the structure. Typical analytical assessments showed that biological mortars were quite effective in increasing the sulfate-resistant service life of sewage culverts.

• Magazine of the Korea Institute for Structural Maintenance and Inspection
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• v.20 no.1
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• pp.38-41
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• 2016

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.7 no.3
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• pp.49-56
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• 1993

This paper describes design and implementation of signal transmission system using LCX as communication media, which has characteristics of high reliability easy for expansion and complex transmission of voice, data and video signal in Electric culvert. In this system, we estimated system performance as result of variable transmission characteristics test. In case of voice signal, transmission loss characteristics improved 5-10(dB] than designed Values in received signal level. In the test of speech quality estimation, we obtained satisfactory result as speech intensity = 3 (QSA value), speech atriculation = 4 (QRK value). As for data and video signal transmission, communication success rates were 981% 1 in monitoring and control functional test. As a result of transmission characteristics test in transmission line and system, transmission range by LCX communication system without repeater can reach in 6Km. This paper presents basic construction method using LCX communication system for total management in Electric culvert.

• Journal of Korea Water Resources Association
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• v.47 no.7
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• pp.587-598
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• 2014

Recently runoff reduction facilities such as detention ponds were rarely used and limited primarily to cases. A specific installation criteria and method of design for runoff reduction facilities is insignificant in our country. Also it has difficult problems with quantification. A detention pond being installed at outfalls and generalized in our country is adopted as basic form with infiltration facilities because quantification index for runoff reduction facilities have not been developed. A processing of detention pond design has to determinate storage volume and outlet form is very complex and wasting human resources and time in the planning step. In this study, we have been unified FFC11-SimPOND being able to simply calculate size with simplified design method of culvert outlet and made a computing model (SimPOND-CO) for practical users.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.435-440
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• 2000

It is important to pay careful attention to construction backfill for the structural integrity of concrete box culvert. The stability of the surrounding soil is important to the structural performance of most culverts. Good compaction by the dynamic compaction roller with big capacity is as effective as good backfill materials to increase the structural integrity of culvert. However structural distress of the culvert could be occur due to the excessive earth pressure by dynamic compaction load. In this study, 16 box culverts were constructed with various compaction materials and construction methods. Three types of on-site soils such as subbase, subgrade and roadbed materials were used as backfill materials in the test program. Compaction methods were adapted based on the site conditions. In most cases, dynamic compaction rollers with 10 to 16 ton weights were used and vibration speed were applied from 2400 to 2500 rpm for the great compaction energy. Some backfill compactions with good quality soils were carried out to examine the effect of EPS(Expanded Polystyrene) panels with changes of compaction thickness. This paper presents the main results of the research conducted to access the engineering performance of the backfill materials. The characteristics of earth pressures are discussed. It is observed that subgrade and roadbed materials are needed more careful compaction than subbase materials. It is shown that EPS panels are effective to mitigate dynamic lateral earth pressure on the culverts. It is also obtained that the dynamic pressure depends on the soil properties. In addition, the coefficient of dynamic earth pressure (K$\sub$dyn/=ΔP$\sub$H/ ΔP$\sub$V/) during compaction is discussed.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.167-174
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• 2011

This research was conducted to propose the design methodologies of post-tensioned concrete pavements (PTCPs) for specialized section pavements. The specialized sections considered in this study included bus stop sections in urban bus-only lanes and culvert existing highway sections that often showed severe failures. The PTCP designs of those specialized sections were performed based on both the stresses and the fatigue failures, and more conservative design results were selected. In the stress based design, the maximum tensile stress under extreme load conditions was obtained using finite element analyses first. Then, the number of tendons and the tendon spacing were determined so that the tensile stress was less than the allowable flexural strength. The AASHTO fatigue failure equations were used in the fatigue failure based design. From this study, the design methodologies of PTCP for bus stop sections in bus-only lanes and culvert existing highway sections were successfully suggested.