• Title/Summary/Keyword: Main-excavation

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A Comparative Study on rural amenities by principal component analysis - Targeting Chungcheongbuk-Do Farming Village Comprehensive Development Project - (주성분 분석을 이용한 농촌마을 자원항목 추출 비교 연구 -충청북도 농촌마을종합개발사업을 대상으로-)

  • Ju, Jae-Cheol;Song, I;Jeong, Da-Yeong;Min, Heung-Gi;Rhee, Shin-Ho
    • Journal of Korean Society of Rural Planning
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    • v.19 no.2
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    • pp.183-192
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    • 2013
  • As the number of aid projects for farming village has been increased, rural amenity is being emphasized. On the contrary, we have a shortfall in excavation and utilization of great resources due to the utilization limit for resources in each village and similarity with the resources from other areas. Thus, we're trying to investigate the ways to make effective use of excellent amenities for farming village development project. In this study, through the principal component analysis, we tried to extract the key factors from the selected areas and examine actual application case of resources. This study categorized the key resource into the big class such as development, farming, nature and experiencing and target areas were categorized into two main classes accordingly. The finding shows 5 example places selected as great areas are taking advantage of extracted excellent resources and 2 target areas are also utilizing enough of excellent resources of each area. Not only limit of used items, subjective view of researcher and resources of each area but also participatory intention of residents and management ways should be additionally considered for another study from now on.

Development of pressurizing support tunneling method and case study of its field application (가압지보 터널공법 개발 및 현장적용 사례 분석)

  • Kim, Dea-Young;Lee, Hong-Sung;Lee, Se-Jin;Lee, Hee-Kwang;Sim, Bo-Kyoung
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.4
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    • pp.397-419
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    • 2012
  • The pressurizing support tunneling method has been developed that overcomes shortcomings of conventional trenchless methods and applied to the field. The main concept of the new method is the pressurization system which, by means of pressurization bag between outer flange of steel ribs and excavated perimeter, applies higher pressure than the pressure relaxed by excavation to the ground to prevent ground displacement. The stability of the support members and effect of displacement control of the new method were verified through 3D numerical analyses. The new method was applied to the construction of a 10.7 m wide, 7.9 m high and 85 m long ramp tunnel that passes under ${\bigcirc}{\bigcirc}$ Expressway. By applying the new method, the tunnel construction was successfully completed in 13.5 months which decreases construction time to 35% compared to conventional methods, and ground displacement was almost negligible.

Modelling the coupled fracture propagation and fluid flow in jointed rock mass using FRACOD

  • Zhang, Shichuan;Shen, Baotang;Zhang, Xinguo;Li, Yangyang;Sun, Wenbin;Zhao, Jinhai
    • Geomechanics and Engineering
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    • v.22 no.6
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    • pp.529-540
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    • 2020
  • Water inrush is a major hazard for mining and excavation in deep coal seams or rock masses. It can be attributed to the coalescence of rock fractures in rock mass due to the interaction of fractures, hydraulic flow and stress field. One of the key technical challenges is to understand the course and mechanism of fluid flows in rock joint networks and fracture propagation and hence to take measures to prevent the formation of water inrush channels caused by possible rock fracturing. Several case observations of fluid flowing in rock joint networks and coupled fracture propagation in underground coal roadways are shown in this paper. A number of numerical simulations were done using the recently developed flow coupling function in FRACOD which simulates explicitly the fracture initiation and propagation process. The study has demonstrated that the shortest path between the inlet and outlet in joint networks will become a larger fluid flow channel and those fractures nearest to the water source and the working faces become the main channel of water inrush. The fractures deeper into the rib are mostly caused by shearing, and slipping fractures coalesce with the joint, which connects the water source and eventually forming a water inrush channel.

A Study on the Architectural Aspect of the Sutra Hall and the Promoters of the Rotating-sutra Case Cabinet of the Yeongguk Temple in the Koryo Dynasty (영국사(寧國寺) 대장전(大藏殿)과 전륜장(轉輪藏)의 조성주체와 건축특성)

  • Lee, Kyung-Mee
    • Journal of architectural history
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    • v.20 no.5
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    • pp.95-109
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    • 2011
  • The building for the Sutra appeared as the Sutra-belief became popular in the early years of the Koryo Dynasty. According to the written documents, there were two types of apparatus to keep sutras, one by fixing the cabinet to the wall and the other by rotating the cabinet at the center of the hall. There are no remains. Recently, at the excavation of the site of the Yeongguk Temple (寧國寺) in the Chungcheong Prevince (영동군), a building which was presumed as the Sutra Hall was recovered at the side of the Main Hall. At the center of the building, of 6meters width and 6meters depth, there was a large stone which had a round trace which was presumed to supporting the rotating sutra-case cabinet. By examining the concerned situations, this building was concluded as the Sutra Hall of the temple. The Yeongguk Temple had a close relationship with the royal household. Budddhist monk Gwangji, son of the 16th King Yejong was lived at the Temple. the tomb of King's advisory priest Wongak was also erected at the Temple. Two monks were well known as the defender of the Sutra. The Sutra Hall of the Yeongguk Temple regarded as a significant example which showed us how the archtectural aspect of the Sutra Hall was shaped in the Koryo Dynasty. It could be said that revealing the architectural aspect of the Stura Hall will help revealing the Buddhist architecture of the Koryo Dynsty which is veiled in many field.

Theoretical and Numerical Study on the Support Pressure for Tunnel Face Stability in Shield TBM Construction (쉴드터널 시공 시 막장안정을 위한 지보압의 이론적.수치해석적 고찰)

  • Kim, Kwang-Jin;Koh, Sung-Yil;Choo, Seuk-Yeun;Kim, Jong-Soo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.8 no.3
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    • pp.197-204
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    • 2006
  • A large sectional tunnelling method using Shield TBM is expected to be popular as domestic demand of long tunnel gets growing. Although a shield tunnelling method has been recognized as prominent method in consideration of stability and applicability in shallow and poor ground, the cases of accident and constructional trouble have been often happened due to unexpected poor ground condition, or selection and use of improper shield machine. Especially, troubling cases at tunnel face are frequently occurred, so supporting pressure control of tunnel face would be the main issue for securing safer and more efficient tunnel excavation using Shield TBM. In this point, we carried out the numerical feed-back analysis to compare the ground deformation pattern with theoretical result at tunnel face.

An analytical model for assessing soft rock tunnel collapse risk and its engineering application

  • Xue, Yiguo;Li, Xin;Li, Guangkun;Qiu, Daohong;Gong, Huimin;Kong, Fanmeng
    • Geomechanics and Engineering
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    • v.23 no.5
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    • pp.441-454
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    • 2020
  • The tunnel collapse, large deformation of surrounding rock, water and mud inrush are the major geological disasters in soft rock tunnel construction. Among them, tunnel collapse has the most serious impact on tunnel construction. Current research backed theories have certain limitations in identifying the collapse risk of soft rock tunnels. Examining the Zhengwan high-speed railway tunnel, eight soft rock tunnel collapse influencing factors were selected, and the combination of indicator weights based on the analytic hierarchy process and entropy weighting methods was obtained. The results show that the groundwater condition and the integrity of the rock mass are the main influencing factors leading to a soft rock tunnel collapse. A comprehensive fuzzy evaluation model for the collapse risk of soft rock tunnels is being proposed, and the real-time collapse risk assessment of the Zhengwan tunnel is being carried out. The results obtained via the fuzzy evaluation model agree well with the actual situation. A tunnel section evaluated to have an extremely high collapse risk and experienced a local collapse during excavation, verifying the feasibility of the collapse risk evaluation model. The collapse risk evaluation model proposed in this paper has been demonstrated to be a promising and innovative method for the evaluation of the collapse risk of soft rock tunnels, leading to safer construction.

A Study on the Change of Shape of "Jagui" (Adze) Used in Korean Traditional Architecture (전통건축에 사용된 자귀의 형태 변화에 대한 고찰)

  • Lim, Chae-Hyun
    • Journal of architectural history
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    • v.20 no.3
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    • pp.23-38
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    • 2011
  • The Axes and Adzes are the oldest tools since the beginning of human history which is used to cut the tree and make part of architecture such as boards, square timber etc. Nowadays, these old woodworking tools especially "Jagui(자귀)" (adze) has been almost disappeared at the working site of residential and cultural properties. It is necessary to study Korean traditional woodworking tools to keep Korean traditional skill and technology. It has been reviewed the change of shape of "Jagui(자귀)" (adze) from before Samhan (삼한) period to Joseon Dynasty through excavated relics and paintings and summarize as follows: Based on excavation relics of Dahori, both plate type blade and pocket type blade are used for "Tokki(도끼)" (axe) and "Jagui(자귀)" (adze). The excavated "Jagui(자귀)" (adze) from Jeongbaikri 356 tomb, near Pyongyang is prototype of "Jagui(자귀)" (adze) used nowdays which has almost same shape as well as the insert method of blade and handle. The auxiliary handle is inserted to blade and the main handle is inserted to the auxiliary handle which is different from the method of Chinese and Japanese "Jagui(자귀)" (adze). The length of handle of "Jagui(자귀)" (adze) until late Joseon Dynasty is short by which we assume it is used for a sitting position as hand held Jagui and from that time long handle has been introduced for a standing position which is called "Sunjagui(선자귀)". "Jagui(자귀)" (adze) has been used since the beginning of human history but it is almost disappeared at the most of woodworking site which is the crisis of Korean traditional architecture and we have to do something to keep it.

Construction of the Digital Archive System from the Records of Westerners Who Stayed in Korea during the Enlightenment Period of Chosun (개화기 조선 체류 서양인 기록물의 디지털 아카이브 시스템 구축)

  • Chung, Heesun;Kim, Heesoon;Song, Hyun-Sook;Lee, Myeong-Hee
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.27 no.4
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    • pp.229-249
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    • 2016
  • This study was conducted to create a digital archive for local cultural contents compiled from the records of westerners who stayed in Korea during the Enlightenment Period of Chosun. The compiled information were gathered from 22 records, and 10 main subjects, 40 sub-subjects and 239 mini-subjects were derived through the subject classification scheme. Item analysis was conducted through 38 metadata and input data types were classified and databased in Excel. Finally, a web-based digital archiving system was developed for searching and providing information through various access points. Suggestions for future research were made to expand archive contents through continuous excavation of westerners' records, to build an integrated information system of Korean digital archives incorporating individual archive systems, to develop standardization of classification schemes and a multidimensional classification system considering facet structure in cultural heritage areas, to keep consistency of contents through standardization of metadata format, and to build ontology using semantic search functions and data mining functions.

Treatment of Contaminated Groundwater Containing Petroleum and Suspended Solids Using DAF and Mixed Coagulation Processes (DAF와 혼화응집공정을 이용한 현탁성 고형물 함유 유류 오염 지하수 처리)

  • Lee, Chaeyoung;Jang, Yeongsu
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.8
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    • pp.25-32
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    • 2010
  • Contamination of soil and groundwater by the compounds of hydrocarbon petroleum has been widely accepted as the main cause that harms the environments and health. To remove those pollutants, absorbing clothes, activated carbons, or oil-water separation devices with the gravity method are employed for treatment. However, those materials and devices cannot remove the emulsion pollutants despite of their efficiency for removing free products. Therefore, we investigated the problems which occur during the groundwater treatment for the highly concentrated suspended solid particles, which can be resulted from excavation, and to propose methods to remove TPH(Total Petroleum Hydrocarbon). After coagulation experiment with high molecular polymers, the concentration of SS(Suspended Solids) and COD(Chemical Oxygen Demand) turned to satisfy the groundwater quality criteria within 5 minutes while the concentration of TPH failed to meet the water quality standard of effluent. Consequently, the water quality criteria for effluent could not be met by single DAF(Dissolved Air Flotation) process. However all water quality criteria could be satisfied after 20 minutes when coagulation reactions are carried out simultaneously in the DAF reactor.

Behavior of 2 Arch Tunnel in Sand (사질토지반에서 2 Arch 터널의 거동)

  • Lee, Sang-Duk;Cheon, Eun-Sook
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.6 no.2
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    • pp.171-182
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    • 2004
  • This study is focused on finding out the mechanical behavior of pillars and the ground adjacent to the tunnel depending on the central tunnel size and the invert during the construction of 2 arch tunnels in the sandy ground. Model tests were performed in the trap door system, which was composed of 3 separately movable plates. Central pillar was installed on the central movable plate to measure the pillar loads during the excavation of pilot tunnel and the main tunnel. The load-transfer and the loosening load were measured at the bottom plates adjacent to the 2 arch tunnels. The ground settlement and displacement of the tunnel lining were also measured. As results, not only pillar load but also the load transfer mechanism was influenced by the construction sequences, central tunnel size, and the invert.

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