• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.1399-1406
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• 2009

Probability distribution of geotechnical properties is very useful information and it is used for evaluating the geotechnical properties itself and calculating probability of failure. In this study, probability distribution of compression index, recompression index, and void ratio are evaluated, and analysis results show that all property distributions satisfy normal and log-normal distribution.

• 한국지반환경공학회 논문집
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• 제25권1호
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• pp.5-11
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• 2024

지반함몰은 인구 밀집도가 높은 도심지에서 주로 발생함으로, 발생 원인을 명확히 파악하여 사전에 대비할 필요가 있다. 지반함몰의 주요 발생원인은 지하매설관의 손상으로 인한 지반 내 공동 생성으로 보고되어 있으나, 지반함몰 발생을 예측하여 대비하기 위한 지하매설관의 속성정보 및 영향인자가 올바르게 구축되어 있지 않은 실정이다. 따라서 본 연구에서는 지하매설물 속성정보 중 지반함몰 발생과 유의미한 상관성을 나타내는 인자를 선정하고, 로지스틱 회귀분석을 통해 회귀식을 제안하였다. 이를 위해, 대상지역의 지하매설물 및 지반함몰 이력정보의 데이터를 수집하였고, 대상지역을 QGIS를 활용하여 100m×100m 크기의 Gird로 구분하였다. Gird 내부에 포함되어 있는 지하매설물 속성정보와 지반함몰 이력정보를 추출하여 전처리를 수행하고 데이터셋을 구축하여 상관분석을 수행하였다. 그 결과, 하수관과 통신관의 매설년도와 통신관, 열배관, 가스관의 평균심도를 제외한 인자가 지반함몰과 유의미한 상관성을 보이는 것으로 나타났다. 또한, 로지스틱 회귀분석을 통해 대상지역의 지반함몰 발생 여부 회귀식을 제안하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.388-392
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• 2003

In this study, various railroad geotechnical informations were standardized. The standardization was progressed by classifying the informations as basic properties, railroad vibrations and design plans. Basic informations included soil properties(27), dynamic property(1), geophysical prospecting(1), and elastic wave prospecting(4). Specification for 'human exposure to whole-body vibration' was used to construct the information of railroad vibration. And in the case of the information of design plan, the way to save by graphic files was chosen. Thus standardized informations examined their application by setting up database. Entity-Relation(E-R) model was used in the design of database and by this, the database system was constructed. This database system will be able to serve the performance enhancement of railroad system.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
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• pp.58-63
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• 2007

We developed a new algorithm for jointly inverting dc resistivity and seismic travel time tomography data based on the multiple constraints: (1) structural similarity based on cross-gradient, (2) correlation between two different material properties, and (3) a priori information on the material property distribution. Through the numerical experiments of surface dc resistivity and seismic refraction surveys, the performance of the proposed algorithm was demonstrated and the effects of different regularizations were analyzed.

• 한국지리정보학회지
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• 제11권2호
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• pp.38-50
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• 2008

부지고유 지진 응답과 그에 따른 지진 재해는 지하 지질 및 지반 동적 특성에 따라 주로 영향을 받는다. 본 연구에서는 지진 응답의 신뢰성 높은 평가를 목적으로, 연구 영역을 포괄하는 확장 영역과 지표면의 지반-지식 자료 획득을 위한 추가 부지 방문 조사라는 새로운 개념을 도입하여 GIS 토대의 지반 정보 시스템(GTIS)을 개발하였다. 역사 지진 피해 기록이 많아 향후 지진 발생 가능성 높은 경주 지역에 대해 GIS 기반 GTIS를 구축하였다. 연구 지역인 경주를 대상으로 지반 특성 및 동적 물성을 대표하는 전단파속도($V_S$)를 평가하기 위한 종합적 지반 조사와 기존 지반 자료 수집을 실시하고 부지 방문 조사를 추가적으로 수행하였다. 경주 지역에 대한 GTIS 내에서 지구통계학적 크리깅 기법을 이용하여 지반 조사 자료로부터 연구 영역 전체의 공간 분포 지층과 $V_S$를 신뢰성 높게 예측하였다. GTIS 내에서 예측된 공간 지층 및 $V_S$를 토대로, 부지 효과에 따른 부지고유 지진 응답의 평가 지표인 부지 주기($T_G$)에 관한 지진 구역 지도를 경주 연구 지역에 대해 작성하였다. 경주의 공간 $T_G$ 분포 지도로부터 2 층에서 5 층 건물의 지진 취약도를 확인하였다. 본 연구에서는 GIS 기반 GTIS 내에서 $T_G$를 토대로 수행된 지진 구역화를 지진 재해 평가 및 저감을 위한 효율적 지역 대책 방안으로 제시하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.987-997
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• 2008

Successful design, construction and maintenance of geotechnical structure in soft ground and marine clay demands prediction, control, stability estimation and monitoring of settlement with high accuracy. It is important to predict and to estimate the compression index of soil for predicting of ground settlement. Lab. and field tests have been and are indispensable tools to achieve this goal. In this paper, Artificial Neural Networks (ANNs) model with Levenberg-Marquardt Algorithm and field database were used to predict compression index of soil in Korea. Based on soil property database obtained from more than 1800 consolidation tests from soils samples, the ANNs model were proposed in this study to estimate the compression index, using multiple soil properties. The compression index from the proposed ANN models including multiple soil parameters were then compared with those from the existing empirical equations.

• 한국지진공학회논문집
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• 제27권3호
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• pp.147-155
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• 2023

This study aims to present a method to evaluate the relative risk of failure due to liquefaction of domestic small to medium-sized earthfill dams with a height of less than 15 m, which has little information on geotechnical properties. Based on the results of previous researches, a series of methods and procedures for estimating the probability of dam failure due to liquefaction, which calculates the probability of liquefaction occurrence of the dam body, the amount of settlement at the dam crest according to the estimation of the residual strength of the dam after liquefaction, the overtopping depth determined from the amount of settlement at the dam crest, and the probability of failure of the dam due to overtopping was explicitly presented. To this end, representative properties essential for estimating the probability of failure due to the liquefaction of small to medium-sized earthfill dams were presented. Since it is almost impossible to directly determine these representative properties for each of the target dams because it is almost impossible to obtain geotechnical property information, they were estimated and determined from the results of field and laboratory tests conducted on existing small to medium-sized earthfill dams in previous researches. The method and procedure presented in this study were applied to 12 earthfill dams on a trial basis, and the liquefaction failure probability was calculated. The analysis of the calculation results confirmed that the representative properties were reasonable and that the overall evaluation procedure and method were effective.

• 한국지진공학회논문집
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• 제26권4호
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• pp.173-180
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• 2022

Most of the drinking water dams managed by the local governments in Korea are earthfill dams, and these dams have almost no geotechnical property information necessary for seismic performance evaluation. Nevertheless, in the rough planning stage for improving seismic safety for these dams, it is necessary to classify their relative seismic hazard against earthquakes and conduct an additional ground investigation. The zero seismic failure probability curve is a curve suggested in this study in which the probability of failure due to an earthquake becomes '0' regardless of the geotechnical properties of the earthfill dam. By examining the method and procedure for calculating failure probability due to an earthquake suggested in previous researches, the zero seismic failure probability curves for an earthquake in 1,000-year and 2,400-year return periods in Korea were presented in the form of a hyperbola on the plane of the dam height versus freeboard ratio (ratio of freeboard to dam height), respectively. The distribution characteristics of the dam height and the freeboard ratio of 81 Korean earthfill dams were presented. The two proposed zero seismic failure probability curves are shown on the plane of the dam height versus freeboard ratio, and the relative seismic hazard of 81 dams can be classified into three groups using these curves as boundaries. This study presented the method of classifying the relative seismic hazard and the classification result.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.392-399
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• 2005

Shear modulus (or rigidity) of dam material is an important parameter which can be directly associated with the deformation of dam. Seepage or leakage of water can cause the defects or cracks of dam body. The existence of cracks and rigidity of dam body are decisive information for the estimation of dam safety. Rigidity of material is mainly determined from S-wave velocity and the defects of dam body can be detected by seismic reflection survey. Therefore, seismic reflection survey will be a desirable method which can give a solution about dam safety problem. Among various physical properties of dam body, S-wave velocity is the most important information but it is not easy to get the information. In this study, diverse measuring techniques of S-wave reflection survey were attempted to get the information about S-wave velocity of dam body. Ultimately, S-wave velocity could be estimated by the analysis of SH reflection events which can be easily observed in shot gather data obtained from SH measuring technique. Meanwhile, P-wave reflection survey was also performed at the same profile. P-beam radiation technique which can reduce the surface waves and reinforce the P-wave reflection events was applied for giving a help to analyse P-wave velocity. In the end, P-and S-wave velocity, Vs/Vp, Poisson's ratio distribution of the vertical section under the profile could be acquired.

• 한국산업융합학회 논문집
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• 제22권2호
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• pp.125-135
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• 2019

In recent years, the digital transformation age represented by the "Fourth Industrial Revolution", which is a universalization of digitalization across all industries, has become a reality. In the construction sector in 2018, the Ministry of Land, Infrastructure and Transport established the Smart Construction 2025 vision and established the 'Smart Construction Technology Roadmap' aiming to complete construction automation by 2030. Especially, in the construction stage, field monitoring technology using drones is needed to support construction equipment automation and on-site control, and a 3D geospatial information model can be utilized as a base tool for this. The purpose of this study is to investigate the factors affecting earthworks work in order to manage changes in site conditions and improve communication between managers and workers in the earthworks plan, which has a considerable part in terms of construction time and cost as a single type of work. Based on this, field management procedures and applications were developed.