• Advances in Computational Design
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• v.2 no.2
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• pp.121-131
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• 2017

Collapse was one of the typical common geological hazards during the construction of tunnels. The risk assessment of collapse was an effective way to ensure the safety of tunnels. We established a prediction model of collapse based on Bayesian Network. 76 large or medium collapses in China were analyzed. The variable set and range of the model were determined according to the statistics. A collapse prediction software was developed and its veracity was also evaluated. At last the software was used to predict tunnel collapses. It effectively evaded the disaster. Establishing the platform can be subsequent perfect. The platform can also be applied to the risk assessment of other tunnel engineering.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1151-1155
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• 2010

Frost depth is one of important factors to design roadway structure, and it can be estimated with numerical simulation on thermal distribution through subgrade soils. Thermal conductivity is a key parameter for accurate prediction on thermal distribution, but there are few studies on thermal conductivity of subgrade soils in Korea. Thermal conductivity can be affected by several factors such as dry density, moisture content, and saturation degree based on previous researches. Two empirical equations to estimate thermal conductivity are applied to access the accuracy of these equations with experimental data. Results indicate that the equation can be used to estimate thermal conductivity with proper quartz fraction.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1267-1274
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• 2005

The system which can manage and analyse the tunnel information in design and construction stage was developed through several years' research named ITIS(Intelligent Tunnel Information System). Now, the system is being modified and improved for the use of international tunnel construction information sharing. Some countries have their own management system for tunnel construction, and one of them, called DEST(Data Evaluation System for Tunneling), is adopted for the international cooperation for this research of development. The aimed system is operated under world wide web environment.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.259-266
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• 2008

In the past, MSW (Municipal Solid Waste) disposal was typically done by recycling, incineration, or landfilling. In South Korea prior to the late 1950's, land burial was usually accomplished by disposal in an open dump. Currently, with increasing concerns and environmental recognition, MSW disposal and landfilling is more restricted. MSW landfill facilities have been developed with certain design and construction specifications. However, these methods have a space for improvement. MSW landfill facilities follow a step wise approach of design, construction, operation and closure management after use in agreement with established environmental and sanitary standards. This study intends to give a technical guidance for installation and consideration of newly established MSW landfill facilities, and also provide an establishment and regular inspection of MSW landfill facilities.

• Journal of the Korean Geotechnical Society
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• v.30 no.10
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• pp.33-44
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• 2014

The preliminary design of suction pile as the supporting system for concrete floating structures was performed for the pilot project of the southwest coast area in Korea. Prior to starting design work, site conditions of the area including ground and hydraulic conditions, and a 100-year return period external force were throughly evaluated. The suction pile for mooring of the offshore floating structures has to satisfy the lateral resistance against external force as well as the penetration ability according to the soil conditions such as soil types, shear strengths, effective stresses, and seepage forces. In the design, the required penetration depths, which were stable for lateral resistance, were evaluated with the diameters of cylindrical suction pile as the final installing ones. And the design suction pressures at each penetrating depths, at which sand boiling did not occur, were assessed through the comparison of penetration and penetrationresistance forces. As a result, it was impossible for suction piles with the diameter range of 3.0~5.0 m to penetrate into required penetration depths. On the other hand, suction piles with the diameter range of 6.0 m and 7.0 m satisfied both the horizontal stability and the penetration ability by design suction pressures at the required penetration depths of 8.5 m and 8.0 m, respectively.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.87-95
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• 2022

The geotechnical information constructed in the National Geotechnical Information DB System has been extensively used in design, construction, underground safety management, and disaster assessment. However, it is necessary to refine the geotechnical information because it has nearly 300,000 established cases containing a lot of missing or incorrect information. This research proposes a method for automatic quality control of geotechnical information using a fully connected neural network. Significantly, the anomalies in geotechnical information were detected using a database combining the standard penetration test results and strata information of Seoul. Consequently, the misclassification rate for the verification data is confirmed as 5.4%. Overall, the studied algorithm is expected to detect outliers of geotechnical information effectively.

• Proceedings of the Korean Geotechical Society Conference
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• 1996.10a
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• pp.141-148
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• 1996

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.639-648
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• 2005

Up to now, practical engineers applying simplicity value of rockfall block weight suggested in design manual without considering in-situ rockfall block weight which reflect joint characteristics. However, the size of rockfall block varies with joint spacing of discontinuities and influences over rockfall analysis results. In this paper, we estimate realistic rockfall block weight distribution using statistical invariances of joint spacing derived from scan-line survey result. And, we study whether this distribution is applicable in practical rockfall analysis directly. As the results of this study, rockfall analysis results that using rockfall block weight distribution estimated from scan-line survey show resonable and realistic outcomes.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1299-1306
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• 2005

The introduction of geodetic methods of absolute displacement monitoring in tunnels has improved the value of the measurements significantly. By using this method, structurally controlled behavior and influences of an anisotropic rock mass can be determined and the excavation and support adjusted accordingly. In this study cases of tunnel monitoring in anisotropic/heterogeneous rock masses are analyzed, and various anisotrpic behavior of tunnel can be estimated. Because rock anisotropy and heterogeneity can have great influence on tunnel behavior, tunnel design considering rock anisotropy and heterogeneity is needed. Also under construction, feedback must be performed by using face mapping and monitoring to prevent over-deformation and tunnel collapse.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1562-1571
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• 2005

The use of geogrid for SRW systems and bridge abutment has increased rapidly over the past 10 years in Korea. The concept of segmental retaining walls and reinforced soil is very old and for example The Ziggurats of Babylonia(i.e. Tower of Babel) were built some 2,500 to 3,000 years ago using soil reinforcing methods very similar to those described in current design. Modern SRW(Semental Retaining Wall) units were introduced in 1960's as concrete crib retaining wall systems. In this paper, the friction properties between segmental concrete units and geogrid are investigated by performing various tests.