• Information and Communications Magazine
• /
• v.20 no.2
• /
• pp.109-117
• /
• 2003

UWB 기술은 주파수 영역에서 광대역을 갖는 임펄스를 사용하므로 목표물로부터 많은 정보를 얻어, 고해상도 레이더 개발이 가능하다. 이러한 UWB 레이더의 특성을 이용하여 한국전기연구원에서는 지중 금속 물체를 탐지하기 위한 지반 탐사 레이더를 개발하였다. 개발된 레이더는 실제환경에서 금속 물체를 탐지하기 위해서 시험되었다. 개발된 레이더는 물체의 깊이에 대해 고해상도를 가졌고, 동작 파장보다 훨씬 작은 금속 물체까지도 탐지가 가능함을 보였다. 본 논문에서는 개발된 지반 탐사 UWB 레이더 시스템을 소개하고, UWB 레이더의 특성 및 UWB 기술에 대해 기술하고자 한다.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2004.03a
• /
• pp.310-325
• /
• 2004

국가전략 6대 분야는 IT(정보기술), BT(생명공학기술), ET(환경기술), NT(극미세기술), ST(우주항공기술) 및 CT(문화기술)로 정부 및 민간부문에서 최근 집중 육성되고 있다. 이중에서 IT는 정보시스템의 계획, 분석, 설계, 구축을 위한 일련의 연결된 형식기법을 통칭하는 용어로 광통신, 디지털방송, 무선통신, 소프트웨어, 차세대 인터넷, 컴퓨터 등을 주요 전략품목으로 삼고 있다. 지반공학에서의 IT는 '계측'이라는 다소 시대에 쳐지는 듯한 용어를 사용하고는 있지만 나름대로 컴퓨터 및 통신기술의 발달과 함께 성장하고 있다.(중략)

• Journal of the Korean Association of Geographic Information Studies
• /
• v.11 no.2
• /
• pp.38-50
• /
• 2008

The site-specific seismic responses and corresponding seismic hazards are influenced mainly by the subsurface geologic and geotechnical dynamic characteristics. To estimate reliably the seismic responses in this study, a geotechnical information system (GTIS) within GIS framework was developed by introducing new concepts, which consist of the extended area containing the study area and the additional site visit for acquiring surface geo-knowledge data. The GIS-based GTIS was built for Gyeongju area, which has records of abundant historical seismic hazards reflecting the high potential of future earthquakes. At the study area, Gyeongju, intensive site investigations and pre-existing geotechnical data collections were performed and the site visits were additionally carried out for assessing geotechnical characteristics and shear wave velocity ($V_S$) representing dynamic property. Within the GTIS for Gyeongju area, the spatially distributed geotechnical layers and $V_S$ in the entire study area were reliably predicted from the site investigation data using the geostatistical kriging method. Based on the spatial geotechnical layers and $V_S$ predicted within the GTIS, a seismic zoning map on site period ($T_G$) from which the site-specific seismic responses according to the site effects can be estimated was created across the study area of Gyeongju. The spatial $T_G$ map at Gyeongju indicated seismic vulnerability of two- to five-storied buildings. In this study, the seismic zonation based on $T_G$ within the GIS-based GTIS was presented as regional efficient strategy for seismic hazard prediction and mitigation.

• Journal of the Korean GEO-environmental Society
• /
• v.15 no.7
• /
• pp.13-21
• /
• 2014

Recently, a great number of natural disasters have more frequently happened than the past. The National Emergency Management Agency of Korea has made preparation for the integrated management system of steep slope lands. There is information based on the steep slope inspection sheets and the underground spatial information related to the prevention against steep slope disasters. Nevertheless, building a complete DB System to prevent the hazards and secure the safeties should be urgently dealt with. It is mainly because the information of the National Disaster Management System is restricted to the text-based brief data. Therefore, the purpose of this study is to suggest the method as to building steep slope DB system for disaster prevention and maximizing the availabilities. This study shows the way of building a web-based DB system having its root in the steep slope inspection sheets. The method of establishing the ideal DB system that has liaisons between the Ministry of Land, Infrastructure and Transport and the National Emergency Management Agency is discussed in this study. Furthermore the optimization of DB utilization will assist the various integrated steep slope management systems based on U-IT which are ongoing projects.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.13 no.4
• /
• pp.32-49
• /
• 2010

Site characterization on geological and geotechnical conditions was performed for evaluating the earthquake ground motions associated with seismic site effects at a small urbanized area, Hongseong, where structural damages were recorded by an earthquake of magnitude 5.0 on October 7, 1978. In the field, various geotechnical site investigations composed of borehole drillings and seismic tests for obtaining shear wave velocity profile were carried out at 16 sites. Based on the geotechnical data from site investigation and additional collection in and near Hongseong, an expert system on geotechnical information was implemented with the spatial framework of GIS. For practical application of the GIS-based geotechnical information system to assess the earthquake motions in a small urban area, spatial seismic zoning maps on geotechnical parameters, such as the bedrock depth and the site period ($T_G$), were created over the entire administrative district of Hongseong town, and the spatial distributions of seismic vulnerability potentials were intuitively examined. Spatial zonation was also performed to determine site coefficients for seismic design by adopting a site classification system based on $T_G$. A case study of seismic zonation in the Hongseong area verified that the GIS-based site investigation was very useful for regional prediction of earthquake ground motions in a small urbanized inland area.

• Tunnel and Underground Space
• /
• v.28 no.6
• /
• pp.547-554
• /
• 2018

Using crowdsourced sensor data collection technique, it is possible to collect high-density ground vibration data which is difficult to obtain by conventional methods. In this study, we have developed a crowdsourced ground vibration data collection system using MEMS sensors mounted on small electronic devices including smartphones, and implemented client and server based on the proposed infrastructure system design. The system is designed to gather vibration data quickly through Android-based smartphones or fixed devices based on Android Things, minimizing the usage of resource like power usage and data transmission traffic of the hardware.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.23 no.6
• /
• pp.559-575
• /
• 2021

Due to the increase in ground excavation work, the possibility of ground subsidence accidents is increasing. And it is very difficult to prevent these risk fundamentally through institutional reinforcement such as the special law for underground safety management. As for the various cases of urban ground excavation practice, the ground subsidence behavior characteristics which is predicted using various information before excavation showed a considerable difference that could not be ignored compared to the results real construction data. Changes in site conditions such as seasonal differences in design and construction period, changes in construction methods depending on the site conditions and long-term construction suspension due to various reasons could be considered as the main causes. As the countermeasures, the safety management system through various construction information is introduced, but there is still no suitable system which can predict the effect of excavation and risk assessment. In this study, a web-based system was developed in order to predict the degree of impact on the ground subsidence and surrounding structures in advance before ground excavation and evaluate the risk in the design and construction of urban ground excavation projects. A system was built using time series analysis technique that can predict the current and future behavior characteristics such as ground water level and settlement based on past field construction records with field monitoring data. It was presented as a geotechnical data visualization (GDV) technology for risk reduction and disaster management based on web-based system, Using this newly developed web-based assessment system, it is possible to predict ground excavation impact prediction and risk assessment.

• Journal of the Korean GEO-environmental Society
• /
• v.16 no.1
• /
• pp.17-27
• /
• 2015

Recently, Korean government has tried out to set up earthquake hazards prevention system. In the system, several geotechnical hazard maps including liquefaction hazard map and landslide hazard map for the whole country have drawn to consider the domestic seismic characteristics. To draw the macro liquefaction hazard map, big data of site investigations in metropolitan areas and provincial areas has to be verified for its application. In this research, we carried out site response analyses using 522 borehole site investigation data in S city during a desirable earthquake. The soil classification was separately compared to shear wave velocity considering the uncertainty of site investigation data. Probability distribution and statistical analysis for the results of site response analyses was applied to the feasibility study. Finally, we suggest a new site amplification coefficient, hereby presented with the similar results of liquefaction hazard mapping using the calculated liquefaction potential index by the site response analyses. Above-mentioned study will be expected to help to follow research and draw liquefaction hazard map in moderate seismic region.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.21 no.1
• /
• pp.23-34
• /
• 2018

Recently, mainly in downtown, there have been frequent safety incidents in underground space like ground subsidence and land sinking. Out of diverse coping measures, the government is carrying forward the establishment of underground space integrated map. As a core element of the underground space integrated map, the 3D geotechnical information is used as major data of underground space impact assessment obliged in accordance with the "Special Act on the Safety Control of Underground Space Safety". The construction method of 3D geotechnical information is drawn when establishing the basic establishment plan of underground space integrated map, and the continuous construction is performed by the Integrated DB Center of National Geotechnical Information. However, it is necessary to draw concrete measures with accuracy, efficiency, and utilization. This study drew the construction plan considering the accuracy, utilization, and efficiency of 3D geotechnical information for the support of underground space safety. For this, accuracy between elevation and underground level is compared using MVS and MakeJiban which are software to construct boring information with geotechnical information in geotechnical information portal system. In the results of general analysis, the milepost-based construction of whole strata in a lump would be the most suitable in the aspect of accuracy, utilization, and efficiency. Based on the results of this study, Plan to construct 3D geotechnical information will be pursued.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.25 no.2
• /
• pp.87-99
• /
• 2023

Ground excavation inevitably causes ground displacement of adjacent ground, and structures and facilities exposed to ground displacement may suffer various damages. Therefore, in order to minimize the damage and damage to adjacent structures and facilities caused by excavation, ground displacement (settlement and horizontal displacement) in the adjacent ground caused by excavation must first be predicted. There is many ground displacement information induced by general braced cut excavation, but the information is not enough for circular shaft excavation. This study aims to provide information on the estimation of ground settlement caused by circular shaft excavation through the case analysis of circular shafts and comparison with braced cut excavation. From this study, it was found that the use of the settlement criterion of braced cut excavation as the settlement management criterion for circular shaft excavation is a conservative approach in terms of safety. But when considering the economic aspect, it may result in overdesign of the wall and therefore, a more reasonable settlement criterion can be needed for circular shaft excavation.