• Geomechanics and Engineering
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• v.29 no.4
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• pp.407-420
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• 2022

Embedded piles, which are typically used in Korea, are precast piles inserted into prebored ground with cement paste. Dynamic pile tests tend to underestimate the bearing capacity of embedded piles because of the undeveloped shaft resistance prior to the curing of the cement paste and the insufficient energy transferred after the curing. In this study, a resistance combination method using the base resistance before the cement paste is cured and the shaft resistance after the cement paste is cured is proposed to obtain a combined load-settlement curve from dynamic pile tests. Two pairs of embedded piles with diameters of 600 and 500 mm are installed. Each pair comprises one pile for the dynamic pile test and another pile for the static load test. The shape of the load-settlement curve obtained using the proposed method is similar to that obtained from the static load test. Thus, the resistances evaluated using the proposed method at selected settlements are similar to those obtained from the static load test. This study shows that the resistance combination method may be used effectively in dynamic pile tests to accurately evaluate the bearing capacity of embedded piles.

• Journal of Arbitration Studies
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• v.11 no.1
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• pp.3-35
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• 2001

$\ulcorner$The South-North Joint Declaration$\lrcorner$ of June 15, 2000 made by President Kim Dae Jung and National Defense Committee Chairman Kim Jong Il will contribute to the activation of economic exchange between south and north Korea. To realize the fundamental spirit of the South-North Joint Declaration, the authorities concerned of south and north Korea have reached an agreement titled $\ulcorner$Agreement on Settlement Procedure of Commercial Disputes$\lrcorner$ last December. In this connection, a speedy and reasonable settlement of commercial disputes arising therefrom is becoming a problem of vital importance between south and north Korea. Also, south and north arbitral institutions have to consider a possible arbitration agreement carefully to solve the disputes systematically under the Agreement, which will serve as an example for similar arrangements and possible harmonization in East-West commercial relations. A variety of dispute settlements including friendly consultations, conciliation and arbitration will be used more frequently within the framework of the bilateral agreements of governmental or non-governmental level which have been concluded in the past between socialist and capitalistic economy countries. There is a growing tendency that East-West trade parties recognize and accept the UNCITRAL Arbitration Rules in their contracts. So it is advisable to use the UNCITRAL Rules in arbitrations of south and north Korea in case that the interested parties fail to agree on applicable rules. Finally it should be noted that pre-arbitral settlement called ‘joint conciliation’ should be reflected in the settlement mechanism of commercial disputes between south and north Korean parties as proved to be successful between the U.S. and China trade in the past.

• Journal of Arbitration Studies
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• v.30 no.4
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• pp.3-29
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• 2020

The WTO's dispute settlement system has played a significant role in settling trade disputes between countries, and its function and role have been expanded by handling about 596 disputes since its establishment in 1995. This shows that the WTO's dispute settlement system is gaining enormous trust among member countries that it recognizes as a fair, effective, and efficient system for resolving trade disputes. The U.S. remains uncooperative in the WTO dispute settlement system, citing disregard for the 90-day deadline for appeals, continued service by persons who are no longer A.B. members, issuing advisory opinions on issues not necessary to resolve a dispute, A.B. review of facts, and review of a member's domestic law de novo. The A.B. claims its reports are entitled to be treated as a precedent. These problems should be gradually improved through various discussions and agreements by establishing a multilateral forum for resolving disputes and gradually ending the problems through reform of the DSU.

• Geomechanics and Engineering
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• v.29 no.3
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• pp.229-236
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• 2022

In this study, a model experiment and field experiment was conducted to introduce the optimal tensile force when constructing a non-open cut tunnel according to the ground conditions of sandy soil. CMR (Concrete Modular Roof) method is economical because of the high precision and excellent durability, and corrosion resistance, and the inserted parts can be used as the main structure of a tunnel. In addition the CMR method has a stable advantage in interconnection because the concrete beam is press-fitted compared to the NTR (New Tubular Roof) method, and the need for quality control can be minimized. The ground conditions were corrected by adjusting the relative density of sandy soil during the construction of non-open cut tunnels, and after introducing various tensile forces, the surface settlement according to excavation was measured, and the optimal tensile force was derived. As a result of the experiment, the amount of settlement according to the relative density was found to be minor. Furthermore, analysis of each tensile force based on loose ground conditions resulted in an average decrease of approximately 22% in maximum settlement when the force was increased by 0.8 kN per segment. Considering these results, it is indicated that more than 2.0 kN tensile force per segment is recommended for settlement of the upper ground.

• Journal of the Korean Geotechnical Society
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• v.25 no.10
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• pp.67-76
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• 2009

Statistical analysis was performed using a series of data on RMR, RMR* and crown settlements collected from sites of weathering rock tunnels in Korea. The crown settlements were predicted by recurrence analysis, exponential function, and artificial neural network (ANN) using collected in-situ data. The result of the prediction fitted well compared to the measured settlement in the order of ANN, exponential function, and recurrence analysis. The range of crown settlement predicted by recurrence analysis widely scattered and promised larger settlement than the measured. Also in all method, the predicted value by RMR well matched compared to the measured settlement predicted by RMR*.

• Journal of the Korean Geosynthetics Society
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• v.7 no.3
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• pp.25-30
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• 2008

In this research, the characteristics of settlement and consolidation behavior of the composite ground formation reinforced by Recycled-Aggregate Porous Concrete Pile (RAPP) were evaluated by conducting a series of laboratory chamber tests. The effect of settlement reduction was verified by comparing the settlement of the composite ground formation with that of the unreinforced ground. In addition, it was studied how much the RAPP can accelerate consolidation in assessment of the degree of consolidation in the composite ground formation. The amount of settlement reduction was decreased with an increase on surcharge pressure, but it was greater than that of the SCP method. The RAPP and the SCP showed a similar rate of consolidation.

• Journal of Arbitration Studies
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• v.14 no.2
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• pp.3-46
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• 2004

To realize the spirit of the South-North Joint Declaration of June 15, 2000, the competent authorities of the South and the North of Korea have reached two Agreements to settle commercial disputes as well as to set up an arbitral organization called 'South-North Commercial Arbitration Commission'. The Commission is an institutional organization for settlement of commercial disputes arising from trade and investment between south and north Korea. Under the situation, it is becoming a problem of vital importance how to manage and control the Commission for prompt and effective settlement of south-north commercial disputes. While analyzing the above two Agreements for dispute-settlement mechanism, the author proposes desirable ideas and directions in connection with the Commission as follows: 1. First of all, the Commission should become a central common system for settlement of commercial disputes which meets the demand of capitalistic market economy. 2. The Authorities of south and north Korea should recognize that the availability of prompt, effective and economical means of disputes resolution such as arbitration and conciliation to be made by the Commission would promote the orderly growth and encouragement of south-north trade and investment. 3. The Korean Commercial Arbitration Board(KCAB) should be designated as the Arbitration Commission of South Korea because the KCAB is the only authorized institution in South Korea, statutorily empowered to settle any kind of commercial disputes at home and abroad.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.8-16
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• 2018

This study examined the long-term behavior of a roadbed using high-speed railway concrete track and roadbed measurement data and evaluated the long-term performance of the track and roadbed. Recently, high-speed railway track type has been adopted as a concrete slab. On the other hand, the concrete track is vulnerable to roadbed settlement. In the case of gravel tracks, it is easy to restore the original state by maintenance even if the roadbed settles. On the other hand, in the case of the concrete track, if excessive settlement of the roadbed occurs, cracks are generated continuously on the slabs and sleepers, resulting in greatly reduced usability. For this reason, it is difficult to restore the original state only by partial maintenance. In this paper, a long-term performance evaluation was carried out on a concrete track during operation by monitoring the measurement data of sensors buried from the beginning of construction for approximately 3 years after the high-speed railway opened. Performance evaluation methods include a performance evaluation of track/roadbed when the train passes, long-term track and roadbed performance evaluation, analysis of the track/roadbed effect on long-term settlement and analysis of the factors influencing long-term settlement. The trail response of KTX-Sancheon was greatest in the track/roadbed performance evaluation by train. The results of the long-term track and roadbed performance evaluation were measured within the standard values. The track and roadbed performance impact assessment with long-term settlement was strongly related to TCL settlement. The influences of the water content and groundwater level were verified by analyzing the external factors of long-term settlement. Through such a method, the stability of a track/roadbed can be secured.

• Journal of the Korean Geotechnical Society
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• v.24 no.5
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• pp.55-64
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• 2008

When the structure is constructed on the soft ground, the embankment is settleed into the soft ground. At this time, the settlement of the structure is needed to predict. We are using bamboo mats construction only as a way of test construction. Under this circumstance, using the equation of Janbu and Perloff, we calculated the settlement, and analyzed the problem, suggesting proper theoretical equations showing the settlement of soft ground using bamboo mat. Using this equations the settlement was calculated and compared with the result of FEM. The result of the application was very close to the numerical value and the trend of theoretical equations. Using the existing equations, the settlement in Janbu's and Perloff's methods were calculated to be 40% of the actual settlement.

• Journal of the Korean Geotechnical Society
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• v.36 no.3
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• pp.5-14
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• 2020

The railway concrete track has been increasingly adopted for high-speed train such as KTX due to its high running stability, improved ride quality for the passengers, and low maintenance cost. However, excessive settlement of the railway concrete track has been monitored at embankment sections of the ◯◯ High-speed Line, resulting in the concerns on the safety of railway operation. In order to establish an effective maintenance plan for the concrete track railway exceeding the allowable residual settlement, it is essential to reasonably predict their long-term settlement behavior during the public period. In this study, we developed a model for predicting the long-term settlement behavior of concrete track using recurrent neural network (RNN) and examined the applicability of the developed model.