• Journal of the Korean GEO-environmental Society
• /
• v.23 no.6
• /
• pp.5-17
• /
• 2022

The performance of the relief wells installed for the purpose of controlling seepage of the dam embankment is affected by various parameters such as diameter, spacing, penetration rate, permeability coefficient of the ground, thickness of the foundation layer. Therefore, when the relief wells are adopted for the purpose of reducing seepage pressure, these parameters should be sufficiently reviewed to determine the installation specifications of the relief wells. This study evaluated the effect of the length of the geosynthetics blanket on the performance of the relief wells installed in the downstream part of the dam embankment with blankets in the upstream and downstream part of the dam embankment as countermeasure methods to control seepage of the dam embankment. In the relationship between the length of the upstream and downstream blanket and the discharge, the discharge of the relief wells decreases as the length of the upstream blanket increases, and on the other hand, the discharge of the relief wells decreases as the length of the downstream blanket increases. In the upper and lower blanket length-spacing relationship, as the length of the upstream blanket increases, the spacing of the relief wells increases and as the length of the downstream blanket increases, the spacing of the relief wells decreases. Therefore, when installing the relief wells in parallel with the blanket, it was found that increasing the length of the upstream blanket is more efficient than increasing the length of the downstream blanket in order to minimize the discharge of seepage discharge and to ensure economic feasibility by wider installation of the relief wells.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.62 no.6
• /
• pp.119-129
• /
• 2020

Through 3D seepage analysis of pressure relief well installed on the embankment of agricultural reservoir, the effects of reducing pore water pressure and hydraulic gradient, and increasing piping safety, depending on diameter (0.2, 0.4, 0.6 m) and space (10, 25, 50 m) of relief well, were analyzed. The conclusions drawn through this study are as follows. i) At the location of pressure relief well, pore water pressure decreases by 25.3~62.5%, and hydraulic gradient decreases by 22.4~55.7%. ii) Between relief wells, pore water pressure decreases by 2.7~40.3%, and hydraulic gradient decreases by 2.8~47.0%, which are relatively less than at the cross section of installed location of relief well. iii) Piping safety factor by critical hydraulic gradient increases by 28.9~125.6% at the location of relief well and increases by 2.9~88.8% between relief wells. iv) Seepage analysis needs to be performed by the 3D method to make evaluation of seepage at the location of relief well and between relief wells possible. v) Additional evaluation is required for various conditions such as waterhead, engineering characteristics of embankment body and its foundation, location, diameter, spacing and depth of pressure relief well.

• Journal of the Korean GEO-environmental Society
• /
• v.21 no.2
• /
• pp.5-13
• /
• 2020

The relief wells have been studied to be effective in seepage control in small dams such as agricultural dams. However, quantitative studies on the effects of the relief well are rare and there is no design standard also. To quantitatively analyze the effects of the seepage control in small dams, the research of up-lift pressure influencing the toe of dam body was conducted by seepage analysis, which investigates the behavior characteristics, according to the conditions of dam and foundation. The effect of seepage control was studied by analyzing the reduction effect of up-lift pressure at foundation ground of the toe of downstream dam slope depending on the installation of the relief well. As a result, it was found that the relief wells are effective in reducing the pore water pressure in the foundation, which can cause piping and sliding failure.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.03a
• /
• pp.687-694
• /
• 2002

This paper presents the results of 3-D analysis on steady state flow in the region where the leakage in a cable tunnel is occurred due to high excess ground water pressure. In numerical modeling, a relief well is selected as a method of reduction in water pressure at the surrounding region of the cable tunnel. The distribution of ground water level after dewatering by relief wells is analyzed, Results show that the amount of dewatering level in the layer of hard rock is about 4.2∼8.6m, and that in the layer of fracture zone is about 5.8∼8.2m. The predicted settlement at the cable tunnel due to the increase of effective stress by dewatering is 0.3mm.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.54
• /
• pp.145-166
• /
• 2012

This article examines the limitations of the choice of law caused by Internationally Mandatory Rules in Entering into the Turn-Key Contracts. In June 2007, Clough Engineering, a corporation based in Western Australia, approached the Federal Court of Australia seeking injunctive relief and leave to commence proceedings against an entity located outside Australia, the Oil & Natural Gas Corp of India (ONGC). Clough had contracted with ONGC to provide a range of services in relation to the construction of gas and oil wells off the coast of India. The contract was governed by Indian law, and included a clause by which the parties agreed to submit their disputes to arbitration. Yet the Federal Court assumed jurisdiction over the dispute, principally because Clough had framed its claim as a plea for relief for contraventions of Australia's Trade Practices Act 1974. The result of this cases that it is possible for an arbitral tribunal to hear a claim made under the Trade Practices Act even if that claim arises "in connection with"a contract the proper law of which is not the law of Australia. However, in Transfield Philippines Inc v Pacific Hydro Ltd, the turnkey contract included a choice of law provision, selecting the law of the Philippines, and a clause providing that all disputes arising out of or in connection with the agreement were to be arbitrated under the ICC Rules, with the seat in Singapore. Hearings were in fact conducted in Melbourne, Australia, although all awards were published in Singapore. The result of this cases that it would not be appropriate for an Australian court to adjudicate claims for misrepresentation under Australian statutes dealing with misleading and deceptive conduct, once the arbitral tribunal had determined, applying appropriate choice of law rules, that such claims are governed by the law of the Philippines. To do so would lead to a multiplicity of proceedings, usurp the jurisdiction of the tribunal and deny the intention of the parties as expressed by them in the arbitration agreement. In short, the Internationally Mandatory Rules as an active part of public order create limitation of party autonomy in choice of law rules in a different way. The court is fully entitled to refuse to use those rules of law applicable on the contract which are in the contradiction to the internationally mandatory rules of law of the forum. And the court may give an effect to those Internationally Mandatory Rules that form a part of a law of foreign country when deciding about applicability of certain rules of applicable law.