• Journal of the Korean GEO-environmental Society
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• v.15 no.10
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• pp.53-62
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• 2014

In Korea, the pipe type that has been well used as sewage pipe from the past is primarily a rigid pipe which is represented by concrete hume pipe, but the use of it is being decreased sharply because of the problems such as tube erosion and incomplete watertightness securing through the time. On the other hand, the use of flexible pipe has been increased because its construction ability is excellent on account of its light weight as well as it is resistant to corrosion. However, because there are lacks of market's confidence in flexible pipe and occurrence cases of partial damage incomplete caused by compaction control, cause analysis and management for them are needed. Therefore, this study tried to estimate the deformation characteristics of pipe caused by each condition through numerical analysis changing construction sequence, rigidity of pipe, strength of ground concrete under the pipe, relative compaction ratio of sand foundation under the pipe and relative compaction ratio of backfill material above the pipe. Evaluation result is that influence on each factor is confirmed and the quality control of sand around the pipe are turned up to be important.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.5
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• pp.469-484
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• 2012

This study aims to numerically investigate ground movement around a square steel pipe as well as a group of square steel pipes induced by its and their ground penetration for trenchless construction of a concrete box. From numerical results, ground movement induced by a square steel pipe is much more dominantly governed by vertical displacement rather than horizontal displacement. Ground settlement induced by pipe penetration is much larger as the overburden becomes lower. The settlement is also shown to be slightly dependent upon the sequence of pipe penetration. More careful construction management is highly in demand during the penetration of upper pipes since their induced settlement occupies approximately 75 percent of total ground settlement after the whole construction of steel pipes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.3
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• pp.711-721
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• 2014

PPWS, a large number of which a main cable of a suspension bridge consists of, must be precisely erected at a target location under construction considering the differences among design conditions. The absolute sag is measured for several PPWSs, which are reference strands and the relative sag is surveyed from them to other PPWSs, which are divided into several groups. And the adjustment of PPWS length is performed to erect it at target configuration. When PPWS is being under erection in a real bridge site, the procedures are as follows; evaluate sag sensitivities according to sag variation factors, calculate an adjustment length of PPWS corresponding to them and adjust a sag of PPWS by controlling the calculated amount of PPWS length. In this study, the differential-related equations of sag sensitivity were proposed for support movement of PPWS. Before site demonstration study of a series of them, we established a catenary model system and accomplished verification tests of them. From test results, the validation of them was done.

• Journal of Korea Multimedia Society
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• v.12 no.8
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• pp.1164-1171
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• 2009

This paper proposes an efficient implementation way of traditional wooden building using Parametric modeling method which uses the relations of numerical value ratio between building materials. Building structures and order of construction for Geunjungjeon of Kyuungbok Palace is digitally implemented proving the efficiency of the suggested proposal. Although the existing digital modeling methods for traditional wooden building emphasize the exterior modeling of the building, our modeling method constructed numerous wooden materials and arranged those pieces orderly so that people can see the interior structures of the building which usually is beyond one's vision. The suggested Parametric modeling method, Multi-Object Texture Mapping, Physical Camera Restoration, and GI Renderer for implementing Geunjungjeon of Kyuungbok Palace can be practically used for digital implementation for other traditional wooden buildings.

• Journal of Digital Convergence
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• v.11 no.8
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• pp.213-218
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• 2013

In this paper, when vehicle inspection is made, the check way is recommended based on the intelligent and personalized in the workplace, education, and other space-time according to the current situation. These results increase productivity, reduce costs, and improve performance. So we designed vehicle inspection recommendation system using ontology. Recommendation method is that components connected concept are shown according to weight value. if components are connected with other concept, the components are extended.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.434-437
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• 2004

본 반층벽체 적용지역의 경우, 침출수의 영향으로 암모니아성 질소의 농도가 최대 29.12mg/L까지 검출되고 있으며 반응물질은 암모니아성 질소제거에 적합한 제올라이트를 선정하였다. 투수성 및 다짐강도를 고려하여 왕사와 50:50의 비율로 혼합, 적용하였으며 지하수 평균유속은 0.0864m/d이고 평균지하수위는 원지반 기준 - 4.0m의 분포를 나타내었다. 지질조사 결과, 적용구간의 지질구조는 매립층, 풍화토, 풍차암, 연암의 순서로 분포하고 있으며, 반응벽체의 설계깊이는 현장 시추조사 결과를 바탕으로 지하수의 Under-pass를 방지하기 위하여 연암층 50cm까지 관입시키도록 설계하였다. 최종적으로 선정된 반응벽체의 규모는 35m(길이) $\times$ 1.2m(두께) $\times$ 8.5 ～ 9.42m(구간별 깊이)로 설계에 반영되었다. 현재, 지하수감시정을 이용한 모니터링 결과, 상부지하수 감시정에서의 오염원은 우기의 영향으로 간헐적으로 발생하고 있으나 하부 지하수 감시정에서의 암모니아성 질소농도는 불검출 되거나 0.5 mg/L 이하로 유지되고 있다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.2066-2067
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• 2007

지중송전선로는 2006년 기준으로 전체 송전선로의 8.8%를 차지하고 있으며 그 점유비율은 점차 증가하는 추세이다. 지중송전선로의 주요 구조물 중 하나인 전력구는 "토목구조물 시공 -부대설비 시설 - 케이블 포설"의 순서로 공정이 진행된다. 전력구 부대설비 중 환기설비, 배수시설에 대한 검토는 토목 구조물의 기초설계시에 설치위치와 더불어 그 규격에 대한 검토가 이루어져여 하나 관련 기준이 명확하지 않아 정확한 검토에 어려움이 따른다. 본 논문에서는 최근 개정된 한전 설계기준 및 제정된 전력구부대설 비시설기준을 토대로 집수정의 규격에 대한 검토기준을 제시하였고 아울러 환기설비에 대한 설계방법을 구체적으로 제시하였다.

• Korean Journal of Construction Engineering and Management
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• v.15 no.6
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• pp.26-34
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• 2014

Highway construction is a combination of linear, repetitive, and highly equipment intensive operations. Various types of construction equipment are deployed to ensure undisrupted performance of construction, and thus productivity improvement and cost-saving can be achieved through well-thought-out planning. The selection of construction equipment is dependent upon construction sequence, site conditions, and construction methods. In the process of planning, management should consider various types of construction methods per each type of construction operation. Also, management should map out proper construction equipment operation plan that takes the construction duration and cost measures into consideration. However, limited availability of historic data from the similar types of operations has been a stumbling block to proper construction planning, making the operations performed based upon experience and intuition guided by rules-of-thumb. As a consequence, the planing phase rarely provided an adequate validity in the implementation phase. The researchers developed a process logic for each construction type that management can utilize from early phase of highway construction planning process. Moreover, derived the construction equipment combination optimized for efficiency by using the process simulation technique. The developed method is expected to be useful for the decision-making process that aims to evaluate efficiency of various process plans and to ensure optimal selection of construction equipment for highway construction projects.

• Journal of the Korean GEO-environmental Society
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• v.17 no.12
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• pp.45-54
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• 2016

In this study, the construction method of new underground continuos impervious wall that the bentonite slurry keeps the stability of excavated trench and the mixture of cement and bentonite plays a role as a constituent of impervious wall in the trench. The merit of homogeneity of the method so called as a cement-bentonite slurry wall enables to accurately make an estimation of hydraulic conductivity of the walls compared with that by other general grouting methods and to verify their waterproof efficiency without difficulty at the design stage. The use of cement-bentonite slurry walls for the containment of groundwater flow has also proven a cost-effective impervious wall technology by employing the simple combination of construction equipments and easy and fast construction procedures. The engineering characteristics of cement-bentonite impervious wall obtained by carrying out the laboratory experiments under various conditions. This study reveals the effect of variation of constituent materials and their mixing methods (Water-Cement-Bentonite) on the engineering characteristics of a composition. Also, this study makes some recommendations on the optimum mixing ratio and mixing sequence for the best quality at the site. That is the most important factors to estimate the construction cost and design of the technique. The comparison is lastly made to evaluate the effect of ordinary Portland and blast furnace slag cement as a bonding material on the behavior of impervious walls.

• Explosives and Blasting
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• v.37 no.1
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• pp.34-47
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• 2019

This case study is concerned with the project of the explosive demolition for the DCRE Incheon plant located in Hakik district in Incheon city. The building was severely aging due to the high temperature and sea winds of hundreds of degrees emitted by chimney-shaped steel structures inside the building. Due to this, the concrete of the column and the beam fell off and rusted rebar were exposed, and some of the slabs were severely damaged, making it difficult for workers to access the structure. Therefore, it is not possible to apply a mechanical demolition method in which heavy equipment enters the interior of the building, and an explosive demolition method was applied to allow the building to be demolished without dismantling the internal facilities of the building. The order of blasting proceeded in the order of (1) building ${\rightarrow}$ (2) chimney 2 ${\rightarrow}$ (3) chimney 1. A total of 406 electronic detonators (Unitronic 600) was used to sequentially initiate the explosives installed at appropriate in building and chimneys.