• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1294-1301
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• 2010

In this study, a case study, where a hazard management for tunnel collapses has been quantitatively undertaken based on the KICT Tunnel Hazard(KTH) index, is presented. From this, it was able to timely inform the field engineers when the more detailed investigation is required for checking if any risky factor is shown on the tunnel face. At the same time, variable additional information such as sensitivities of major influence factors are also provided to field engineers from the methodology given in this study. The additional information would be helpful for better understanding of tunnel hazard level at the current tunnelling stage and following the required actions for more detailed checks of risky factors.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1130-1141
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• 2010

Even though a number of historic structures in Korea need to be repaired, an intensive research on their engineering performance has rarely been investigated. Herein, we attempted to provide a methodological approach via the explicit finite element analysis to investigate geotechnical aspect of the performance of the dry-stone wall structures. To do so, we summarized relevant literature on the world-wide historic stone structures as well as its analysis in terms of modern geotechnical engineering. The method of the explicit finite element analysis has been briefly summarized. The numerical results on an idealized block structure show that the displacement of blocks and the distribution of earth pressure is different from the conventional theory of the retaining wall because of the discrete nature of the dry-stone wall structure.

• Economic and Environmental Geology
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• v.17 no.1
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• pp.57-78
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• 1984

The object of this study is to offer the standarized data for the design and calculating engineering cost of the rock excavation an the construction of the 3rd and 4th Seoul Subway lines From Jnauary to March in 1983, this study was carried out by the both methods of the field and laboratary studies. In the field, the geological survey in the entire area of Seoul City and sites on the subway lines were carried out and also a site measure of uniaxial compressional strength of rock masses by using Schmidt hammer was done. The labartory studies were carsied out by a study of preuions surveyes, microscopic studies of the mineral composition and degree of weathering of rocks, and measure of uniaxial compressional strengths Finally an engineering classification of each rock masses of South Africa council for Scientific and Industrial Research, CSIR, after Bieniawski, 1974. was done. In this method of classification 6 parameters such as strength of intact rock material, rock quality designation, spacing of fractures, condition of fractures, groundwater conditions, and the effect of fracture strike and dip orientation in tunnelling were used to evaluate rating of each rock mass.

• Geomechanics and Engineering
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• v.14 no.5
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• pp.453-458
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• 2018

Geomechanical parameters are important factors for engineering projects during design, construction and support stages of tunnel and dam projects. Geostatistical estimation methods are known as one of the most significant approach at estimation of Geomechanical parameters. In this study, Azad dam headrace tunnel is chosen to estimate Geomechanical parameters such as Rock Quality Designation (RQD) and uniaxial compressive strength (UCS) by ordinary kriging as a geostatistical method. Also Rock Mass Rating (RMR) distribution is presented along the tunnel. Main aim in employment of geostatistical methods is estimation of points that unsampled by sampled points.To estimation of parameters, initially data are transformed to Gaussian distribution, next structural data analysis is completed, and then ordinary kriging is applied. At end, specified distribution maps for each parameter are presented. Results from the geostatistical estimation method and actual data have been compared. Results show that, the estimated parameters with this method are very close to the actual parameters. Regarding to the reduction of costs and time consuming, this method can use to geomechanical estimation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.1050-1058
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• 2008

The application of TBM tunneling has been progressively increased since the first entrance into Korea in 1985. In order to an apprehension and operation development of TBM method which has excellent boring in hard rock tunnel, this study has analyzed mutual relation of lose time and TBM boring from actual construction result TBM tunneling. This study compared an analyzed result with TBM tunnelling construction results of Korea, America, Japan, analyzed a primary factor of TBM boring effect and suggested operation development method from the analyzed results. accordingly this study can be used an index when similar construction apply TBM method to planning steps.

• Tunnel and Underground Space
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• v.12 no.4
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• pp.284-290
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• 2002

Over the past few decades, a considerable number of studies have been conducted on GIS(Geographic Information System) to process spatial date. As GIS comes to be used in many fields and used by many people, Web GIS which is a GIS system used on the internet, was proposed as a good tool to maintain the need. There is an increasing demand for Web GIS to provide more opportunity for users to manage and to analyze geotechnical data. This study mainly focused on the design and application of Web GIS particularly with geotechnical data, including design of efficient database structure for borehole data. A practical application of the Web GIS to tunnelling site has been successfully completed by the design of several analytical functions.

• Geotechnical Engineering
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• v.1 no.1
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• pp.31-46
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• 1985

An extensive program of tunnel instrumentation has been Implemented in the construction of the Seoul Subway Line 3 and 4, in which the NATM was adopted as the main tunnelling technique. Among more than ten instrumented sections in the downtown area, five representative test sections were selected for analysis in this study, with an emphasis on the surface settlement and crown settlement. Variations of the surface and crown settlement. Variations of the governing factors, such as ground conditions, tunnel geometry, and construction conditions are described in this paper. Possible mechanisms for ground deformations occurring at different stages of tunnel construction are formulated, based on overall interpretation of the field observations and data obtained.

• Geotechnical Engineering
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• v.9 no.3
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• pp.61-66
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• 1993

In this paper, the incorporation of qualitative(or soft) data, such as outputs of geophysical tests or construction experience which has so far been cumulated, was discussed for rock classsification. Geostatistics wart used for this research since the parameters for the design of tunnels are spatially correlated. In particular, indicator kriging technique, which is one of non -parametric approaches, was used. As a selection criteria for an optimal classification, the cost of errors was adopted and the binary classes were only considered for rock classification. In future, incorporating an appreciable amount of available qualitative data will be necessary in tunnelling projects in which quantitative data are scarce. In this respect, this research is of great significance.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.181-187
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• 2003

This paper describes a study of the influence of shield tunnel construction on the displacements and stresses induced in the linings of existing nearby parallel tunnels. The paper presents a brief review of a set of laboratory scale model research programme investigating the influence of tunnel proximity and alignment, liner stiffness on the nature of the interactions between closely spaced tunnels in clay. A total of two sets of carefully controlled physical model tests were performed. A cylindrical test tank was developed and used to produce clay samples of Speswhite kaolin. In each of the tests, three model tunnels were installed in order to conduct two interaction exts that have been carried out to investigate the interaction problem between parallel tunnels. The results of these tests are compared with the results of finite element analysis to investigate the techniques that must be used to obtain reliable numerical solutions to this type of problem.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1275-1282
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• 2005

This paper deals with the numerical study for excavation crossing the fault zone and the change of support pattern in field. The numerical analyses by FLAC program were performed to evaluate the suitable support pattern influenced by the width of Fault Zone, considering rock mass condition(RMR classification). Based on the results, it is found that partial reinforcement or degrading support pattern is suitable, when the width of Fault is under 3m. But when the width of Fault is more than 6m(0.5D), extra support pattern for fault zone is acceptable. At field, this result is generally used as a guide in the construction of roadway tunnel, but it is also possible to vary this assessment along the condition of fault.