• Title/Summary/Keyword: excavation survey

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A Case study of steel sheet pile (강널말뚝을 이용한 국내.외 시공 사례)

  • 여병철;김광일
    • Proceedings of the Korean Geotechical Society Conference
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    • 1994.09a
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    • pp.111-118
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    • 1994
  • The use of steel sheet pile walls as barrier walls have the temporary for coffer dam, retaining wall in excavation, etc., but also permanent of semi-permanent for harbor construction, containment systems, vertical barrier systems for waste disposal (landfill) or subway in excavarion. In all these applicaions the resistance of the structure to seepage plays an important role. Also the stability and longevity of the construction, the possibility of permanent control and survey make the steel sheet pile wall a nearly perfect vertical barrier from a technical and economical point of view.

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A Case Study on the Cause and Reinforcement of Railroad Facilities Settlement According to the Ground Excavation (지반굴착에 따른 철도시설물의 침하 원인 및 보강 사례연구)

  • Oh, Beyung-Sam
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.10
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    • pp.85-94
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    • 2012
  • Recent development trend of construction projects in the urban area is the efficient use of insufficient land, however caused to difficult construction conditions because of many adjacent structures. This paper presents the case study that analyzed the ground settlement of railroad structure for the double track railway project of Gyeongui line, adjacent to the high rise building under ground excavating for substructure work, considering interaction of soft ground characteristics. Field survey and measurement works were carried out during construction of station and excavation of high rise building, and field data were analyzed to find the source of settlement of platform and railway. In addition, the soil reinforcement and foundation restoration were performed using in-situ injection method, i.e., D-ROG(Digitalized Restoring On Grout) method which filled the pore of bottom and around of foundation with micro-cement.

액화석유가스(LPG) 지하저장기지에서의 TSP(Tunnel Seismic Prediction)탐사

  • Cha, Seong-Su
    • Journal of the Korean Geophysical Society
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    • v.5 no.2
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    • pp.75-86
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    • 2002
  • A TSP(Tunnel Seismic Prediction) survey which is modified VSP(Vertical Seismic Profiling) survey applied in tunnel was carried out at Pyongtaek and Incheon liquefied petroleum gas(LPG) storage cavern during excavation. The TSP survey in Pyongtaek LPG storage cavern which is located below Namyangho was performed to confirm the location and orientation of the fault detected at pre-investigation stage. The TSP survey was carried out in access tunnel, construction tunnel, and watercurtain tunnel to characterize 3 dimensional figure of the fault. The results of TSP survey are compared four in vestigation boreholes drilled in shelter of access tunnel. The fault was also detected by borehole survey and the location was coincided with the result of TSP survey. Depending on the result of TSP survey and core logging, the design such as cavern layout and length was changed. Another TSP survey was performed in Incheon LPG storage cavern which is located below sea. Because of poor geological information at pre-investigation stage and suffering from heavy leakage of groundwater, the TSP survey to detect fracture zone was carried out. The support and grouting design was reflected by the result of TSP survey.

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A Study on Data Analysis of Ground Vibration.Noise Dust Dispersion Measurement for Enhancing Safety at the Construction Sites - Focussed on Blasting and Piling in Sedimentary and Igneous Rocks in the Youngnam Area - (건설 현장에서 안전성 향상을 위한 지반진동.소음.비산먼지 측정자료의 분석에 관한 연구 -영남지역의 퇴적암.화성암층에서의 발파 및 항타작업을 중심으로-)

  • 안명석;류창하;박종남
    • Explosives and Blasting
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    • v.19 no.3
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    • pp.91-104
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    • 2001
  • As in Korean environments with mountainous and hilly areas, the rock generally has to be removed in construction or civil engineering work in tunnelling or excavation for development in urban area. Explosives should be used for blasting, which may cause serious problems on local people for their claim for compensation due to ground vibration, noise. For safe and economic blasting, geology and engineering characteristics of rocks such as discontinuities of rock or weathering are very important factors, together with site characteristics for prediction of ground vibration. In this study, conducted were the detailed study for major rocks most widely distributed in the South-east area, in-situ geological survey, geological and geochemical analysis, and further laboratory uniaxial rock stress, seismic velocity of core samples together with in-situ seismic velocity measurements. Regulations on ground vibration and noise were reviewed for assessing their adaptabilities, and a total of 4,856 measured blasting vibration data were examined for enhancing the confidence level in estimating the predictive formulation using scaled distance statistically.

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Seismic reflection imaging ahead of tunnel face using 3 component geophones (3성분 지오폰을 이용한 막장전방 예측 탄성파탐사)

  • Jo Churl Hyun;Cha Young Ho;Yang Jong Hwa;Bang Ki Moon
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.412-417
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    • 2005
  • To ensure the safety of the tunnelling without the loss of economy, the tunnel seismic profiling(TSP) method for the prediction ahead of tunnel face, begins to be used routinely in these days. TSP method does not interfere the tunnelling works while the horizontal drilling does, and its prediction length is longer than that of the drilling. Yet the most frequently adopted technique of TSP in Korea is the multi-shot and 2 receiver array using in-hole receivers, even though this array requires as many as 26 drill-holes for receiver installation and ballasting, which results in 3-6 hours of suspension in excavation work. In this paper, multi-receiver and lesser shot array using side-wall attached 3 component geophones is to be described to prove the efficiency in terms of the survey time as well as the reliability of the method by comparison of the predicted weak points and the face mapping results. The predictions mostly agreed with the real fractures or joint developed zones which have been confirmed during the excavation. It also has been found that TSP method can be effectively applied to perform draining ground water ahead of tunnel face by imaging the geologic discontinuities.

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Water-induced changes in mechanical parameters of soil-rock mixture and their effect on talus slope stability

  • Xing, Haofeng;Liu, Liangliang;Luo, Yong
    • Geomechanics and Engineering
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    • v.18 no.4
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    • pp.353-362
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    • 2019
  • Soil-rock mixture (S-RM) is an inhomogeneous geomaterial that is widely encountered in nature. The mechanical and physical properties of S-RM are important factors contributing towards different deformation characteristics and unstable modes of the talus slope. In this paper, the equivalent substitution method was employed for the preparation of S-RM test samples, and large-scale triaxial laboratory tests were conducted to investigate their mechanical parameters by varying the water content and confining pressure. Additionally, a simplified geological model based on the finite element method was established to compare the stability of talus slopes with different strength parameters and in different excavation and support processes. The results showed that the S-RM samples exhibit slight strain softening and strain hardening under low and high water content, respectively. The water content of S-RM also had an effect on decreasing strength parameters, with the decrease in magnitude of the cohesive force and internal friction angle being mainly influenced by the low and high water content, respectively. The stability of talus slope decreased with a decrease in the cohesion force and internal friction angle, thereby creating a new shallow slip surface. Since the excavation of toe of the slope for road construction can easily cause a landslide, anti-slide piles can be used to effectively improve the slope stability, especially for shallow excavations. But the efficacy of anti-slide piles gradually decreases with increasing water content. This paper can act as a reference for the selection of strength parameters of S-RM and provide an analysis of the instability of the talus slope.

Case Study on Location of Possible Tension Crack in Rock Slope (암반 비탈면의 인장균열 위치 선정에 관한 사례 연구)

  • Jeon, Byung-Gon;Kim, Jiseong;Kang, Gichun
    • Journal of the Korean Geotechnical Society
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    • v.37 no.3
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    • pp.5-17
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    • 2021
  • This study aims to investigate the causes and countermeasures for the occurrence of tension cracks in the slope of the rock mass of heavy equipment for road construction. Electric resistivity survey was performed to investigate the expandable tensile crack range. As a result of examining the distribution of soft zones in the rock mass, a low specific resistance zone was found at the bottom of the access road where tensile cracks occurred. It was confirmed that a low resistivity zone was distributed near the top of the excavation slope. Therefore, reinforcements was performed by determining the location of the possible tensile crack as the top of the excavation slope. Two rows of reinforced piles and anchors were proposed as a reinforcement method, and the slope stability analysis showed that the allowable safety factor was satisfied after reinforcements.

Application of TSP Suvey to Predict the Ground Conditions Ahead of Tunnel Face (터널막장 전방 파악을 위한 TSP(Tunnel Seismic Prediction) 탐사 사례 연구)

  • Cho, Sung-Won;Lee, Hyo;Yoo, Jae-Won;Kim, Do-Hun Dave;Nam, Seung-Hyeok
    • Explosives and Blasting
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    • v.31 no.2
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    • pp.40-49
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    • 2013
  • To predict ground conditions ahead of the tunnel face, seismic refraction survey has been widely used. But due to the development in seismic equipment and techniques, tomography using borehole and others are actively applied in recent years. This study has a purpose to prevent stability problems during excavation and construction of tunnels by predicting unfavorable ground conditions such as fault, fractured zone and rock quality variation zone ahead of the tunnel face using TSP survey equipment. In this study, the validity of predicting ground conditions ahead of tunnel face by TSP survey has been evaluated through the case study in the road construction site.

The Safety Assessment of Embankment by Three Dimensional Electrical DC Modeling (3차원 전기비저항 모델링을 통한 제체의 안정성 분석 연구)

  • Oh, Seok-Hoon
    • Journal of the Korean earth science society
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    • v.29 no.6
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    • pp.447-453
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    • 2008
  • Recently, the electrical DC survey has frequently been performed to assess the safety of embankment. This study showed that the damaged section of embankment could be appropriately detected by the survey only when the three dimensional effect was correctly considered. The shape of the three dimensional embankment was numerically implemented, and a proper modeling was performed to confirm the effect by analyzing the apparent and inverted true resistivity. Then, the field work was carried out. The three dimensional interpretation distinguished the erroneous weak zones from the geometrical artifact, and the embankment was ensured as safe both by the additional survey performed in rainy season and the partial excavation for direct observation.

3-Dimensional Terrain Model of Ruins Distribution Using GIS (GIS를 이용한 유적분포 3차원 지형모델)

  • 곽영주;장용구;강영신;강인준
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.04a
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    • pp.455-460
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    • 2004
  • Recently, As a part of NGIS project, cultural-assets digital map is produced by cultural properties administration and local autonomous entities. Cultural-assets unified GIS(Geographical Information System) is essential to cultural properties managers and other organizations which is executing land related business for appling it at planning stage. With explosive national land developments, it has been obligated to implement surface survey by the cultural properties protection Art(clause 2, Atr 74). In this paper, the author used the district of Sachon city and made 3D terrain model using digital map which is made of It5000 scale. moreover, the author improved to RDBMS(Relational Database Management System) structure and remodeled the existing DB design in detail. The author suggest to realize shape and kind of remains which have 3D information of accuracy and actualization from surface survey to excavation.

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