• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.399-406
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• 1999

Recently, the construction of the several highway bridges in the karst area have encountered severe problems associated with cavities and sinkholes. To solve this problems, it is important to understand the distribution characteristics of cavities in the construction site on limestone area. This paper briefly describes the different types, the distribution control factors and the infill sediment types of lime-cavities in the study area, bridge site in the karst area and propose the effective method of survey design. Cavity system may be divided into two main groups, 1)'slot and cave system'and 2)'sinkhole and cave system'. And the shape, the size and the distribution pattern of cavity are controlled by three main factors - rock type, geological structure and ground water condition. Additionally, infill sediment may be considered as one of the important design factors for foundation design and divided into four types by sediment properties. There are geophysical thechnics and geologic survey and drilling test, etc. by the survey method to interpretate characteristics of cavity system, and this methods are optimally designed at the site investigation stage.

• Structural Engineering and Mechanics
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• v.63 no.3
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• pp.293-302
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• 2017

This study deals with a numerical investigation of load transfer along interfaces of jacketed columns using finite element models. Appropriate plasticity and constitutive models are used to simulate the response of concrete and steel bars. Experimental data were used to calibrate the simulation of mechanical characteristics. The different compressive strength of core and jacket concrete, the confinement ratio, the dowels' diameter size and the load pattern shapes were considered. The path diagrams along the interfaces elucidate the areas around the dowel bars where due to stress concentration plastic hinges and intense discontinuities are created. The stress flow also depicts the contribution of confinement of the jacketed area to the overall resonant load capacity of the core column. The scope of the research is to identify and quantify the shear transfer along the interfaces of strengthened elements.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.427-434
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• 2000

When a large number of hazardous road cut-slopes are spreaded in widely scattered areas, the effective investigation and evaluation method that is able to decide the risk of hazardous road cut-slopes, is required. Many different evaluation techniques were suggested by many different researchers based on their demands, but there are the limited researches on the experimental evaluation technique which can be utilized by personnel who does not have much experiences on the road cut-slopes. In this study, the appropriate and effective evaluation method of the dangerous slope is suggested and this method can be used by both inexperienced and experienced persons. Therefore, this is the one of the effective ways that can mitigate the possibility of landslides.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.722-726
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• 2010

Inventory survey is process collecting data about cut slope. It's different from inspection. It contains not only basic information about cut slope, especially location, GPS positioning, height, length, weathering, joint direction, water conditions but also level of danger and damage. Collected data are being used get at status about cut slope along national roads. And It helps judging about priority of detailed investigation. According to results of analysis, we found better method about maintenance of cut slope. Later on, if inventory research is finished, we will understand characteristics of collapse slopes.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.10a
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• pp.23-34
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• 2006

In a oo dam at oo city of Gyeongbuk, severe damages have been occurred on lower part of dam due to heavy rainfall for several years. This caused significant impediment for maintaining its original function. This is considered as an excellent case for overall improvement of stability of dam system through successful investigation and construction work. This paper present comprehensive specifications that are generalized and used for securing stability of dams by quoting this example.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1012-1017
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• 2010

Sewer Pipes are not being managed for twenty years after laying. So, The life span of sewer pipes is on the decrease. For solve the life span decrease of sewer pipes, correct checking of questions and measure preparation are necessary through investigation in sewer pipes. This research investigated on the state of sewer pipes in the housing and industrial sites through CCTV(closed-circuit television) and device of digitalized strain investigation. And, a result is as follows. A results of PE, PVC, GRP, CSP investigations were found of pipe-transformation state by earth pressure and external load.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.121-128
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• 2001

This is a case study of stability analysis and reinforcement design for the tunnel where the collapse of the entrance slops occured along the fault zone developed in the bed rock. According to the site investigation, the main factor of sliding is the influence of fault gouge and heavy rainfall. Considering the in-situ condition, the versatile reinforcement methods is needed, and so the close investigation on the site area was accompanied with the stability analysis of tunnel and slops. The FRP(Fiberglass reinforced plastic) grouting method improved the defect of Steel Umbrella Arch Method, such as oxidation, low work efficiency, the material's heavy weight, is adapted as the reinforcement methods.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09b
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• pp.13-20
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• 2010

This paper presents the results of a numerical investigation on the ground deformation in deep excavation with emphasis on the groundwater lowering. Using the stress-pore pressure coupled analysis Consideration to the effect of ground excavation and groundwater interaction were carried out and a series of two-dimensional finite element model was employed to perform a parametric study on a wide range of soil profile and initial ground water table condition.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09b
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• pp.88-95
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• 2010

Screw piles(Helical piles and anchors) are increasingly used to support and rehabilitate reinforced structures subjected to both tensile and compressive axial loads. This study presents a variety of detailed investigation on especially pull-out characteristics of screw piles performed to both reduced scale and numerical analysis to identify fundamental failure mechanisms and empirical optimized geometry of screw piles. It was found that the pull-out characteristics of screw piles are influenced with mainly different frequencies of compaction around soil and screw pile's pitch and followings are practical data based on empirical analysis.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11b
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• pp.183-195
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• 2000

Slopes near a dam body can be categorized into 4 groups, such as right and left abutment slopes, reservoir slopes, slopes along the access road and slopes along the relocated road. For each of the geological investigation, the design standards, the evaluation methods of safety and the maintenance methods, both abutment slopes in the four dams have different characteristics from the conventional cut slopes in that they can severely affect the dam safety. From this point of view this study compares and analyzes the geological investigation methods, the status of design and construction, evaluation method of safety, and monitoring & maintaining methods for four major dams in Korea, such as Soyanggang dam, 'Andong dam, Chungju dam and Boryong dam.