• Journal of Conservation Science
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• v.17 s.17
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• pp.83-94
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• 2005

Host rock or the standing sculptured Buddha in the Yongamsa temple is macular porphyritic biotite granite, which has gone through mechanical and chemical weathering. The rock around the Buddha statue is busily scattered with steep inclinations that are almost vertically discontinuous planes with the strikes of $N8^{\circ}E$. Especially the development of the joints that cross the major joints causes the structural instability of the rock. The rock of the Buddha statue is separated into several rock blocks because of many different discontinuity. Thus it is estimated that the bed rock has not only plane and toppling failure but also wedge failure in all the sides. Since the differential pressure is imposed on the body of the Buddha in the host rock, it is urgent to give a reinforce treatment of geotechnical engineering for the safe of its structural stability. Very contact area of joints have turned into soil, which promotes the growth of weeds and plant roots, then aggravates the mechanical weathering of the rock. Thus conservational treatments should also be considered to get rid of secondary contaminants and vegetation along the discontinuities and to prevent further damages.

• Journal of the Korean GEO-environmental Society
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• v.17 no.7
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• pp.5-13
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• 2016

This research is focused on the seepage behavior of embankment which had the weak zone with big permeability. The distributed TDR (Time Domain Reflectometer) and point sensors such as settlement gauge, pore water pressuremeter, vertical total stressmeter, and FDR (Frequency Domain Reflectometer) sensor were used to measure the seepage characteristics and embankment behavior. Also, the measured data were compared to the data of 2-D and 3-D numerical analysis. The dimension of model embankment was 7 m length, 5 m width and 1.5 m height, which is composed of fine-grained sands and the water level of embankment was 1.3 m height. The seepage behavior of measuring and numerical analysis were very similar, it means that the proper sensing system can monitor the real-time safety of embankment. The result by 2-D and 3-D numerical analysis showed similar saturation processing, however in case of weak zone, the phreatic lines of 2-D showed faster movement than that of 3-D analysis, and finally they converged.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.534-544
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• 2019

Because the pile-bent of IPM Bridge is projected from the soil surface, excessive displacement of abutment can be induced. According to design guide of IPM Bridge, the shape of the bridges used in this study was applied to the maximum applicable 120.0m span, 30-degree for skew angle, and 10.0m for the protruded pile-bent height. The maximum displacement by the maximum span application condition of the IPM Bridge was calculated using this bridge model, and the safety of a horizontal displacement of the IPM Bridge was investigated based on the allowable displacement presented by Bozozuk. The maximum horizontal displacement of the IPM Bridge was calculated to be larger in the winter shrinkage condition than in the summer expansion condition, the horizontal displacements were more affected by the length of a bridge than by the skew angle. And the vertical displacement was not affected by the skew angle and length. As the span increases, the horizontal displacement increases significantly, the horizontal displacement at 120.0m span length was found to exceed the allowable displacement proposed by Bozozuk. However, the moment generated in the pile-bent did not exceed the plastic moment.

• Journal of the Korean Geotechnical Society
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• v.23 no.4
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• pp.161-167
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• 2007

In this study, ultimate lateral load capacity of piles is analyzed with consideration of lateral stress effect. Based on results obtained in this study, a method for the estimation of ultimate lateral load capacity is proposed. This makes it possible to more realistically estimate the ultimate lateral load capacity under various stress states caused by in-situ soil condition and pile installation process. Calibration chamber test results with various soil conditions were used in the analysis. From the test results, it was found that effect of the lateral stress was greater than that of the vertical stress on the ultimate lateral load capacity of piles. It was also found that, as the relative density increases, displacements required to reach the ultimate state increases, showing relative displacements of around 14% and 18-25% for $D_R$ : 55% and 86%, respectively. Based on results obtained in this study, a methodology for the estimation of ultimate lateral load capacity of piles using correction factors was proposed. Results from proposed method matched well measured results.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.4
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• pp.305-330
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• 2023

Unlike NATM tunnels, Shield TBM tunnels have split linings. Therefore, the stress distribution of the lining is different even if the lining is under the same load. Representative methods for analyzing the stress generated in lining in Shield TBM tunnels include Non-joint Mode that does not consider connections and a 2-ring beam-spring model that considers ring-to-ring joints and segment connections. This study is an analysis method by Break-joint Mode. However, we do not consider the structural role of segment lining connections. The effectiveness of the modeling is verified by analyzing behavioral characteristics against vibration loads by modeling with segment connection interfaces to which vertical stiffness and shear stiffness, which are friction components, are applied. Unlike the Non-joint mode, where the greatest stress occurs on the crown for static loads such as earth pressure, the stress distribution caused by contact between segment lining and friction stiffness produced the smallest stress in the crown key segment where segment connections were concentrated. The stress distribution was clearly distinguished based on segment connections. The results of static analysis by earth pressure, etc., produced up to seven times the stress generated in Non-joint mode compared to the stress generated by Break-joint Mode. This result is consistent with the stress distribution pattern of the 2-ring beam-spring model. However, as for the stress value for the train vibration load, the stress of Break-joint Mode was greater than that of Non-joint mode. This is a different result from the static mechanics concept that a segment ring consisting of a combination of short members is integrated in the circumferential direction, resulting in a smaller stress than Non-joint mode with a relatively longer member length.