• Korean Institute of Interior Design Journal
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• v.21 no.6
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• pp.186-193
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• 2012

This study is to reveal the periodical form of the 4 staged building sites with the size and the site composition of the master plan and floor plan of the Ungjindan (altar) from the Ungjindan excavation works in 2011. In order to project the research results aiming to the purpose of the study, the basic study was done with collecting data about shrine architecture for its architectural characteristics and case studies with ancestral facilities such as the Ak hae dok (national-level ancestral ritual to the big mountain, ocean and river) to understand the exact form of the site plan and architectural composition elements through the general information and excavation status. In addition, with the current situation and information from the excavation works the planned measurement scale will be calculated in inference for the size of the construction by stages and speculate the floor plan composition of the shrine architecture.

• Journal of Drive and Control
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• v.20 no.4
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• pp.133-139
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• 2023

A weighing system calculates the bucket's excavation amount of an excavator. Usually, the excavation amount is computed by the excavator's motion equations with sensing data. But these motion equations have computing errors that are induced by assumptions to the linear systems and identification of the equation's parameters. To reduce computing errors, some commercial weighing system incorporates particular motion into the excavation process. This study introduces a linear regression model on an artificial neural network that has fewer predicted errors and doesn't need a particular pose during an excavation. Time serial data were gathered from a 30tons excavator's loading test. Then these data were preprocessed to be adjusted by MPL (Multi Layer Perceptron) or CNN (Convolutional Neural Network) based linear regression models. Each model was trained by changing hyperparameter such as layer or node numbers, drop-out rate, and kernel size. Finally ID-CNN-based linear regression model was selected.

• Journal of the Korean Geosynthetics Society
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• v.19 no.1
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• pp.11-23
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• 2020

In this paper development artificial neural networks (ANN) for preliminary design and prediction of urban tunnelling and deep excavation-induced ground settlement was presented. In order to form training and validation data sets for the ANN development, field design and measured data were collected for various tunnelling and deep-excavation sites. The field data were then used as a database for the ANN training. The developed ANN was validated against a testing set and the unused field data in terms of statistical parameters such as R², RMSE, and MAE. The practical use of ANN was demonstrated by applying the developed ANN to hypothetical conditions. It was shown that the developed ANN can be effectively used as a tool for preliminary excavation design and ground settlement prediction for urban excavation problems.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.271-278
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• 2002

Recently, deep excavation for high-rise buildings occurs frequently to accommodate the rapidly increasing population in urban area. The stability of the earth retaining structures for deep excavation becomes more critical. The behavior of the earth retaining structures should be accurately predicted in a design stage, but the predicted behavior is different from the measured data due to uncertain soil properties and problems in construction. In this study the back-analysis using Powell's optimization theory was performed to match the measured deflection and results obtained from back-analysis were presented.

• Journal of the Korean Geosynthetics Society
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• v.14 no.4
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• pp.23-33
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• 2015

Together with the wall stiffness, a berm has the role of deciding the stability of a temporary retaining wall before structure installation after excavation. Especially in case of loose or soft soil excavated ground, the role of berm is very important. In this study, the measurement data obtained from the temporary retaining wall in the bermed excavation site in urban and numerical analysis are used to investigate the effects of berm's dimension (width and slope), excavation depth and ground property on the maximum horizontal displacement of the temporary retaining wall. The measurement data indicated that the wall displacement varied to the berm's width. That is, as the berm width decreased, the wall displacement increased. As a result of numerical analyses, the maximum wall displacement increased as slope increased and berm width decreased. This means that the berm is effectively restrained to the wall displacement. As excavation depth increased, the effect of berm's slope and width increased. In case of the same berm condition, the wall displacement restrained as ground property increased.

• Journal of the Korean GEO-environmental Society
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• v.11 no.2
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• pp.61-68
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• 2010

Recently, it is a trend of the underground excavation to become larger and deeper for more effective use of available space and with the advent of new excavation technologies. The ground typically has a complex stratigraphy. The excavation can lead to large deformation in the nearby structures and large earth pressure on the wall. This can lead to serious problem in the stability of the wall. For the retaining wall to be safely constructed, it is important that the stratigraphy and engineering properties of the ground be accurately estimated, based on the excavation plan and appropriate excavation method. This study uses the measured field data and numerical results to characterize the characteristics of the lateral deformation of the retaining wall. A touredof six field data were analysed. SUNEX, a numerical program which uses the elasto-plastic model to represent the soil, was used. It was shown that the measured deformations exceeded the proposed values for shallow excavations. Overall, the maximum lateral deformation was within the proposed value and hence, the walls were analyzed as safe.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.5
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• pp.357-371
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• 2023

In cable tunnel construction using TBM, the vertical shaft is an essential structure for entrance and exit of TBM equipment and power lines. Since a shaft penetrates the ground vertically, it often encounters rock mass. Blasting or rock splitting methods, which are mainly used to the rock excavation, cause public complaints due to the noise, vibration and road occupation. Therefore, mechanical excavation using vertical shaft excavation machine are considered as an alternative to the conventional methods. However, at the current level of technology, the vertical excavation machine has limitation in its performance when applied for high strength rock with a compressive strength of more than 120 MPa. In this study, the potential utilization of waterjet technology as an excavation assistance method was investigated to improve mechanical excavation performance in the hard rock formations. Rock cutting experiments were conducted to verify the cutting performance of the abrasive waterjet. Based on the experimental result, it was found that ensuring excavation performance with respect to changing in ground conditions can be achieved by adjusting waterjet parameters such as standoff distance, traverse speed and water pressure. In addition, based on the relationship between excavation performance, uniaxial compressive strength and RQD, it was suggested that excavation performance could be improved by artificially creating joints using the abrasive waterjet. It is expected that these research results can be utilized as fundamental data for the introduction of vertical shaft excavation machines in the future.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.521-532
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• 2008

Supporting system design and construction management for the soft and hard rock layers with fractured zones are very important theme for the safety of temporary retaining wall, surrounding ground and structures in the urban deep excavation for the construction of subway, railway, building etc. The prevailing design method of supporting system for the soft and hard rock layers in the deep excavation is mostly carrying out by simplification without proper consideration for the characteristic of rock discontinuities. Therefore the behaviors of rock discontinuities and fractured zones dominate the whole safety of excavation work in the real construction stage, serious disaster due to the failure of temporary retaining wall can be induced in the case of developing large deformations in the ground and large axial forces in the supporting system. This paper introduces examples of deep excavation where the soft and hard rock layers with fractured zones were designed to be supported by shotcrete and rock bolt, deformations of corresponding ground and supporting systems in the construction period and increments of axial force in the upper earth anchors and strut due to the these deformations were investigated through detailed analysis of measurement data, the results were so used for the management of consecutive construction that led to the safe and economical completion of excavation work. The effort of this article aims to improve and develop the technique of design and construction in the coming projects having similar ground condition and supporting method.

• Geomechanics and Engineering
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• v.29 no.3
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• pp.249-258
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• 2022

A disc cutter is an excavation tool on a tunnel boring machine (TBM) cutterhead; it crushes and cuts rock mass while the machine excavates using the cutterhead's rotational movement. Disc cutter wear occurs naturally. Thus, along with the management of downtime and excavation efficiency, abrasioned disc cutters need to be replaced at the proper time; otherwise, the construction period could be delayed and the cost could increase. The most common prediction models for TBM performance and for the disc cutter lifetime have been proposed by the Colorado School of Mines and Norwegian University of Science and Technology. However, design parameters of existing models do not well correspond to the field values when a TBM encounters complex and difficult ground conditions in the field. Thus, this study proposes a series of machine learning models to predict the disc cutter lifetime of a shield TBM using the excavation (machine) data during operation which is response to the rock mass. This study utilizes five different machine learning techniques: four types of classification models (i.e., K-Nearest Neighbors (KNN), Support Vector Machine, Decision Tree, and Staking Ensemble Model) and one artificial neural network (ANN) model. The KNN model was found to be the best model among the four classification models, affording the highest recall of 81%. The ANN model also predicted the wear rate of disc cutters reasonably well.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.5 no.1
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• pp.40-45
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• 2002

The calculation of earthwork plays a major role in the planning and design phases of many civil engineering projects, such as seashore reclamation; thus, improving the accuracy of earthwork calculation has become very important. In this paper, we propose an algorithm for finding a cubic spline surface with the free boundary conditions, which interpolates the given three-dimensional data, by using B-spline and an accurate method to estimate pit-excavation volume. The proposed method should be of interest to surveyors, especially those concerned with accuracy of volume computations. The mathematical models of the conventional methods have a common drawback: the modeling curves form peak points at the joints. To avoid this drawback, the cubic spline polynomial is chosen as the mathematical model of the new method. In this paper, we propose an algorithm of finding a spline surface, which interpolates the given data, and an appropriate method to calculate the earthwork. We present some computational results that show the proposed method, of the Maple program, provides better accuracy than the method presented by Chen and Lin.