• Geomechanics and Engineering
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• v.5 no.2
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• pp.99-118
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• 2013

Construction of the extension project of the Bangkok MRT Blue Line underground railway was recently started in 2011. The construction of approximately 5 km long underground tunnel and 4 deep excavations of underground station are considered to be the most important geotechnical works. The pressuremeter was selected as a high-quality in situ testing of the soil to evaluate design parameters for the project. In addition, other field and laboratory tests such as vane shear and $CK_0U$ triaxial tests were included in the investigation programme. This paper aims to present the ground conditions encountered along the MRT Blue Line extension project as well as the site investigation and interpretation techniques with particular focus on the pressuremeter tests. The results are also compared with the pressuremeter investigation from the previous Bangkok MRT project.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1322-1327
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• 2010

Ready-mixed shotcrete mixed with high quality materials and can be controled shotcrete quality is producted in plants and transported to construction fields, so do not need a field batch plant. In this study, the field construction system that can be applied Ready-mixed Shotcrete to construction fields was proposed, and the all-in-one silo that was the key component of the field construction system was design. It was performed to evaluate the constructability that the field construction process analysis in case of applying a field batch plant and the all-in-one silo, the cost analysis of the material production and transport in a road tunnel was also performed to evaluate the economic feasibility of Ready-mixed shotcret.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.428-444
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• 2010

After underground excavation being introduced in dometic, many technologies have been storing up. One of them, measurement, has been recognized as an important item under excavation construction. But, unlike a large-scale construction, it was not been treated importantly at the general small-scale structures with poor ordering and original design was unchanged under construction was normal if the problem didn't occur on monitoring. In this paper, the site which safe and economical management as well as shortening construction period was made effectively using measurement result was introduced. Also, the site which was completed safely with analyzing measurement and reinforcement when unusual symptom happened was introduced. Using measurement result effectively will be able to obtain the safety and prevent unnecessary economical loss.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.210-220
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• 2005

We have analyzed the stability for cut-slopes at main street 3-2 line section in Pa-ju local industrial complex. After studying an additional boring test, laboratory test and face mapping etc., we have determined the extent of reinforcement, slope inclinations and soil strength parameter from the analysis of test results. After changing the inclination of slopes for ground limit and carrying out the analysis of slope stability, we applied the Mass Nailing Method to the site because of need for reinforcement to soil and weathered rock slopes. In slope for soft and hard rock sections, we also reinforced the sections that are difficult to obtain the safety without reinforcement in alteration zone.

• Structural Engineering and Mechanics
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• v.65 no.6
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• pp.689-698
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• 2018

This study focuses on a novel procedure for the robustness assessment of reinforced concrete (RC) framed structures under threat-independent damage scenarios. The procedure is derived from coupled dynamic and non-linear static analyses. Two robustness indicators are defined and the method is applied to two RC frame buildings. The first building was designed for gravity load and earthquake resistance in accordance with Eurocode 8. The second was designed according to the tie force (TF) method, one of the design quantitative procedures for enhancing resistance to progressive collapse. In addition, in order to demonstrate the suitability and applicability of the TF method, the structural robustness and resistance to progressive collapse of the two designs is compared.

• Geotechnical Engineering
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• v.13 no.2
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• pp.169-184
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• 1997

A semi -analytical solution is derived to solve the elastic-plastic behavior of the axisymmetric tunnels in Drucker-Prager medium. Based on this analytical solution, a computer program FDAXP. is developed. Parametric studies are carried out to verify the FDAXP program, and the results were found to be satisfactory. This simple solution could be incorporated into the preliminary design, analysis of deep underground tunnel as well as tunnels with unfavourable geotechnical conditions. The program provided a useful means of checking the Drucker-Eraser model and iris associated computational algorithms in other tunnel programs.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.89-96
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• 2001

A concrete lining of NATM tunnel is the final product of a process that involves planning and evaluation of user needs, geotechnical investigations, analysis of ground-lining interaction, construction, and observations and modifications during construction. The designer must consider the lining in context of the many function, construction, and geotechnical requirements. Also, the loss of supporting capacity of shotcrete lining due to poor rock qualities and shotcrete erosion must be considered. The values, shapes, and estimating methods of rock load and water pressure are very different with every designers. Estimating methods of rock loads used in the design of NATM tunnel concrete lining are investigated. Numerical analyses are done in various conditions. And the rock loads estimated from radial stress and plastic zone are compared respectively.

• Geotechnical Engineering
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• v.4 no.2
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• pp.15-24
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• 1988

To identify the stability of cantilever retaining wall in safe state by the deterministic method, these potential modes of such geotechnical failures as bearing capacity, horizontal sliding and overturning are analysed using Advanced First Order Second Moment (AFOSM) method. All design variables are assumed of the normal distribution and to be statistically independent. Considering the correlations between the single modes, structural system reliability index is 2. 05. Even if the safety factors are larger than the required value in the codes' by the conventional deterministic method, the system reliability of this structure may not be Judged to be safe state since the system reliability index is much lower than general value of 3.

• Geomechanics and Engineering
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• v.20 no.5
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• pp.421-432
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• 2020

Cutting of rocks is very common encountered in tunneling and mining during underground excavations. A deep understanding of rock-tool interaction can promote industrial applications significantly. In this paper, a distinct element method based approach, PFC^3D, is adopted to simulate the rock cutting under different operation conditions (cutting velocity, depth of cut and rake angle) and with various tool geometries (tip angle, tip wear and tip shape). Simulation results showed that the cutting force and accumulated number of cracks increase with increasing cutting velocity, cut depth, tip angle and pick abrasion. The number of cracks and cutting force decrease with increasing negative rake angle and increase with increasing positive rake angle. The numerical approach can offer a better insight into the rock-tool interaction during the rock cutting process. The proposed numerical method can be used to assess the rock cuttability, to estimate the cutting performance, and to design the cutter head.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1317-1323
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• 2009

A finite element analysis was performed for new earth retention system that is a kind of truss tower with non-supported excavation. A 2D finite element model was adopted in this study to investigate the behavior of the earth retention system. Just because this non-supported truss tower system is too complex to model in 2D plain-strain condition to itself, so have to simplify it by the conception of equivalent rigidity. The horizontal displacement of the wall and lateral earth pressure distribution on the wall were computed. And it is compared with NAVFAC design manual.