• Title/Summary/Keyword: Primary settlement

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Enhanced Stabilization of Carcasses by Retrofitting Burial Sites to Bioreactor (매몰지 생물반응조 개조를 통한 사체의 안정화 촉진)

  • Kim, Geonha;Jeon, Haeseong
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.10
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    • pp.679-684
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    • 2014
  • Many burial sites were constructed to suppress the spread of foot and mouth disease during outbreak. Defected burial sites were removed when leachate leak is presumed and carcasses were moved to the circular storage tanks. However, carcasses were not decomposed possibly due to low water content, low microbial activities, and poor mixing. In this research, storage tank containing carcasses in it was modified to bioreactor to accelerate stabilization. Liquids with nutrients were added and circulated to maintain the optimum water content while extraneous microorganisms were augmented. Settlement was used as the primary index for assessing stabilization rate, and the consolidation theory was utilized to estimate the expected final settlement. 30% of carcasses is expected to be decomposed and removed from the storage tank for five years of bioreactor operation.

A Study on the Consolidation Settlement Due to the Vertical Drain Method by the Implicit Finite Difference Scheme (음적차분해석법을 이용한 연직배수 공법에 의한 압밀침하에 관한 연구)

  • Park, Sung Zae;Jung, Du Hwoe;Jeong, Gyeong Hwan;Lee, Kyeong Joon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.5
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    • pp.1243-1251
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    • 1994
  • The implicit finite difference program was developed to evaluate the relationship between time and consolidation ratio within the zone of vertical drain effective radius. In the evaluation, the excess pore water pressure was considered to dissipate in two directions, namely, vertical and radial flow direction. To calculate subsoil stress increments in the soil due to multi-step embanking, the foundation soil was assumed to be an isotropic and homogeneous elastic medium and the initial excess pore water pressure was estimated by using Skempton's parameters whose condition is plane strain and elastic phase of pore pressure response within the soft ground. Regarding to the settlement estimation, immediate and primary consolidation settlements were calculated. The secondary or delayed consolidation settlement was not considered. Numerically calculated excess pore water pressure and settlements were similar to the measured data in situ. Thus, this method can be used to predict the time-consolidation ratio of each layer treated by vertical drain method.

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A Study on International Disputes with Korean Distant-Water Sea Fisheries (한국의 원양어업관련 국제분쟁 사례연구)

  • 김민종
    • The Journal of Fisheries Business Administration
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    • v.34 no.1
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    • pp.69-85
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    • 2003
  • The primary objective of this thesis is to study, case by case, the international disputes for fishing rights between fishing nations and costal states never imagined till the introduction of the UN Convention on the Law of the Sea adopted in 1982 and came into effect in November 16, 1994, which governs the high seas and EEZ in a new manner. Such a study is to provide help in the understanding on this new marine system and how to deal with. This is addressed by the perspectives of disputes (a) in the high seas between fishing nations having traditionally enjoyed the principle of the freedom of the high seas and costal states, (b) in the EEZ between fishing nations and costal states possessing the exclusive jurisdiction over living marine resources and sovereign rights for determining allowable catch and the surplus in its EEZ. The article can be divided into four main parts. First, both the general principles of the settlement of international disputes, and the nature and procedures described in the UNCLOS are introduced. Second, it gives cases of tuna long-liner, North Pacific trawler and squid jigger occurred in the coastal states EEZ, and analyses the problem in both terms of its background and final judgment. It further describes the possible issues in case it depends on the International Tribunal for the Law of the Sea for its settlement. Third, closely tied to above, important points such as the right of hot pursuit, prompt release of vessel and crew, and the limits of cooperation with costal states inspector on board fishing vessels are considered mostly based on the UNCLOS, Bilateral Agreement and UNIA. Finally, the article concludes as follows ; The need for broad analyses on the nature of international suits and legal system for the settlement, to win the case before the International Tribunal for the Law of the Sea or coastal states court, is really acknowledged. However, considering the lack of previous studies about it, it is preferably recommended that governmental efforts for making legal standards to cover the judicial costs, for helping industry out of becoming bankrupt.

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A Study on the Evaluation of Dynamic Behavior and Liquefaction Cau8ed by Earthquake of Sea Dike Structures on the Ground (방조제 축조 예정지반의 지진에 의한 액상화 거동 평가)

  • 도덕현;장병욱;고재만
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.35 no.2
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    • pp.43-56
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    • 1993
  • The laboratory tests are performed on how the liquefaction potential of the sea dike structures on the saturated sand or silty sand seabed could be affected due to earthquake before and after construction results are given as follows ; 1. Earthquake damages to sea dike structures consist of lateral deformation, settlement, minor abnormality of the structures and differential settlement of embankments, etc. It is known that severe disasters due to this type of damages are not much documented. Because of its high relative cost of the preventive measures against this type of damages, the designing engineer has much freedom for the play of judgement and ingenuity in the selection of the construction methods, that is, by comparing the cost of the preventive design cost at a design stage to reconstruction cost after minor failure. 2. The factors controlling the liquefaction potential of the hydraulic fill structure are magnitude of earthquake(max. surface velocity), N-value(relative density), gradation, consistency(plastic limit), classification of soil(G & vs), ground water level, compaction method, volumetric shear stress and strain, effective confining stress, and primary consolidation. 3. The probability of liquefaction can be evaluated by the simple method based on SPT and CPT test results or the precise method based on laboratory test results. For sandy or silty sand seabed of the concerned area of this study, it is said that evaluation of liquefaction potential can be done by the one-dimensional analysis using some geotechnical parameters of soil such as Ip, Υt' gradation, N-value, OCR and classification of soils. 4. Based on above mentioned analysis, safety factor of liquefaction potential on the sea bed at the given site is Fs =0.84 when M = 5.23 or amax= 0.12g. With sea dike structures H = 42.5m and 35.5m on the same site Fs= 3.M~2.08 and Fs = 1.74~1.31 are obtained, respectively. local liquefaction can be expected at the toe of the sea dike constructed with hydraulic fill because of lack of constrained effective stress of the area.

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Analysis of stability control and the adapted ways for building tunnel anchors and a down-passing tunnel

  • Xiaohan Zhou;Xinrong Liu;Yu Xiao;Ninghui Liang;Yangyang Yang;Yafeng Han;Zhongping Yang
    • Geomechanics and Engineering
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    • v.35 no.4
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    • pp.395-409
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    • 2023
  • Long-span suspension bridges have tunnel anchor systems to maintain stable cables. More investigations are required to determine how closely tunnel excavation beneath the tunnel anchor impacts the stability of the tunnel anchor. In order to investigate the impact of the adjacent tunnel's excavation on the stability of the tunnel anchor, a large-span suspension bridge tunnel anchor is utilised as an example in a three-dimensional numerical simulation approach. In order to explore the deformation control mechanism, orthogonal tests are employed to pinpoint the major impacting elements. The construction of an advanced pipe shed, strengthening the primary support. Moreover, according to the findings the grouting reinforcement of the surrounding rock, have a significant control effect on the settlement of the tunnel vault and plug body. However, reducing the lag distance of the secondary lining does not have such big influence. The greatest way to control tunnel vault settling is to use the grout reinforcement, which increases the bearing capacity and strength of the surrounding rock. This greatly minimizes the size of the tunnel excavation disturbance area. Advanced pipe shed can not only increase the surrounding rock's bearing capacity at the pipe shed, but can also prevent the tunnel vault from connecting with the disturbance area at the bottom of the anchorage tunnel, reduce the range of shear failure area outside the anchorage tunnel, and have the best impact on the plug body's settlement control.

A Study on the two systems for Commercial Disputes Resolution (상사분쟁해결제도의 이원화(二元化)에 관한 일고(一考))

  • Sin, Han-Dong
    • Journal of Arbitration Studies
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    • v.8 no.1
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    • pp.123-148
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    • 1998
  • Recently many controversies originate for varies reasons, ranging from normal market competition to honest disagreements about rights. Disputes also arise from the clash between institutions and individuals. A free society should provide many systems for resolving controversies. We think of the courts as being primary, but, of course, they are not. In Korea, and in most other parts of the world, disagreements are resolved informally, without the need for judicial intervention. Settlements are worked out privately, usually without lawyers and certainly without judges. Most of judges are finding it difficult to cope with the needs and demands of society. Many businessmen who no longer want to get involved in lawsuits, are looking for alternative methods for resolving their disputes. However, there are actually two systems, litigation and arbitration only, to resolve disputes with binding both parties concerned. Litigation emphasizes on the equity and the justice with allowing three time's judgment for the resonable resolution, and arbitration, which is not subject to appeal, stress on the economic settlement rather than justice. Arbitration process results in a final and binding decisions. Although arbitration is a voluntary procedures that is created by the parties themselves, arbitration differs from mediation and conciliation because of its binding power. Arbitration is today coming into fashion as our primary methods for settling disputes. No company wants to have its funds tied up for long periods. Many parties prefer that the decision be final, rather than facing the prospect of extended appellate litigation. Therefore, government must encourage parties to settle their disputes by arbitration instead of litigation.

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A Study on the Characteristics of Consolidation of Soils (I) (The Influence of Pre-consolidation Load of Soils on Consolidation Characteristics) (압밀특성에 관한 연구 (I) (선행하중이 압밀특성에 주는 영향))

  • 류능환;강예묵
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.18 no.4
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    • pp.4242-4250
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    • 1976
  • The determination of the pre-consolidation load known to have a great effect on the consolidation characteristics of the soil have been researched and discussed in detail by many other researchers. A study was undertaken to investigate and compare the effect of pre-consolidation loads on the coefficient of permeability and the consolidation characterisics of soil through the consolidation test on the three types of soil samples. The results of this study are follows; 1. Large compression index is dependent on initial void ratio of the sample being used and the pressure-void ratio curve shows a curved linear relationship in over-consolidated area but a linear relationship in normally consolidated area.2. Settlement-time curve is S-shaped where the pressure is larger than pre-consolidation load and regardless of over-burden pressure, it is a similar straight line respectively in the secondary consolidation area. 3. Primary consolidation ratio of the sample increases almost linearly with the increase of over-burden pressure but the coefficient of volume compressibility decreases linearly with the increase of it. 4. Time factor of a certain degree of consolidation increases with over-burden pressure but the coefficient of consolidation decreases with it in over-consolidated area. There is a linear relationship between them in normally consolidated area. 5. The void ratio of completion point of primary consolidation decreases linearly with over-burden pressure. 6. The coefficient of permeability of sample decreases linearly with over-burden pressure in normally consolidated area, also it increases linearly with increment of the void ratio of the sample.

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Thermal volume change of saturated clays: A fully coupled thermo-hydro-mechanical finite element implementation

  • Wang, Hao;Qi, Xiaohui
    • Geomechanics and Engineering
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    • v.23 no.6
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    • pp.561-573
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    • 2020
  • The creep and consolidation behaviors of clays subjected to thermal cycles are of fundamental importance in the application of energy geostructures. This study aims to numerically investigate the physical mechanisms for the temperature-triggered volume change of saturated clays. A recently developed thermodynamic framework is used to derive the thermo-mechanical constitutive model for clays. Based on the model, a fully coupled thermo-hydro-mechanical (THM) finite element (FE) code is developed. Comparison with experimental observations shows that the proposed FE code can well reproduce the irreversible thermal contraction of normally consolidated and lightly overconsolidated clays, as well as the thermal expansion of heavily overconsolidated clays under drained heating. Simulations reveal that excess pore pressure may accumulate in clay samples under triaxial drained conditions due to low permeability and high heating rate, resulting in thermally induced primary consolidation. Results show that four major mechanisms contribute to the thermal volume change of clays: (i) the principle of thermal expansion, (ii) the decrease of effective stress due to the accumulation of excess pore pressure, (iii) the thermal creep, and (iv) the thermally induced primary consolidation. The former two mechanisms mainly contribute to the thermal expansion of heavily overconsolidated clays, whereas the latter two contribute to the noticeable thermal contraction of normally consolidated and lightly overconsolidated clays. Consideration of the four physical mechanisms is important for the settlement prediction of energy geostructures, especially in soft soils.

A case study on an optimal analysis technique of primary measurements for safety management of fill dam (필댐의 안전관리를 위한 주요 계측 데이터의 최적 분석기법에 대한 사례 연구)

  • Jeon, Hyeoncheol;Yun, Seong-Kyu;Kim, Jiseong;Im, En-Sang;Kang, Gichun
    • Journal of Korea Water Resources Association
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    • v.54 no.spc1
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    • pp.1155-1166
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    • 2021
  • In this study, statistical analysis was performed to suggest the optimal analysis techniques for the main measuring instruments of the fill dam, such as seepage, crest settlement, and porewater pressure gauge. In addition, correlation analysis with water level and rainfall data was performed. Based on the results of descriptive statistical analysis for each instrument, porewater pressure gauges could be classified into 3 groups or 2 groups through principal component analysis, In the case of the group having a high correlation with the water level instrument, the correlation between the gauges was also large. In the case of seepage instrument, the distribution showed an extremely asymmetric distribution, so for quantitative analysis, the average seepage during non-precipitation and precipitation could be estimated through decision tree analysis. In the case of the crest settlement instrument, the correlation analysis showed that the correlation between the gauges was large, but the relationship with the water level instrument did not show a significant linear relationship, so EMD analysis was performed to analyze it in more detail. It is judged that principal component analysis, decision tree analysis, and data filtering method can be applied to analyze the behavior of pore water pressure meters, seepage, and crest settlement instrument as major measurement items of fill dam.

Study on the Characteristics of Consolidation(II) -The Effects of Load Increment Ratio Consolidation Characteristics- (압밀(壓密) 특성(特性)에 관(關)한 연구(硏究)(II) -하중(荷重) 증가율(增加率)이 압밀특성(壓密特性)에 미치는 영향(影響)-)

  • Kang, Yea-Mook;Ryu, Neung-Hwan
    • Korean Journal of Agricultural Science
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    • v.4 no.1
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    • pp.88-93
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    • 1977
  • The following is the result of experiment on consolidation test under various load increment ratios by alternation of standard load increment ratio. The more load increment ratio was, the more settlement was resulted. But expansions were not associated with load increment ratios. Primary consolidation took longer period to complete as load increment ratio was decreased. And under the condition of over-consolidated range, the completion of primary consolidation took longer period as the load was incremented. Under the condition of normal consolidated range, there was no change in time of completing primary consolidation. The coefficient of consolidation was decreased with increment of consolidation load, and the coefficient of consolidation had high values as the load increment ratio was increased. The values of ratio of secondary consolidation was highest near the transition point of consolidation curve.

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