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Collaborating Authors
The Eighteenth International Offshore and Polar Engineering Conference
Expansion Characteristics of Ground By Pulse Power
Kim, Tae-Hoon (Researcher, Civil Eng. Research Team, Institute of Construction Technology, Daewoo E&C Suwon, Gyunggi, South Korea) | Cha, yung-Seob (Researcher, Civil Eng. Research Team, Institute of Construction Technology, Daewoo E&C Suwon, Gyunggi, South Korea) | Kim, Seon-Ju (Researcher, Civil Eng. Research Team, Institute of Construction Technology, Daewoo E&C Suwon, Gyunggi, South Korea) | Chae, Young-Su (Professor, Dept. of Civil Engrg Univ. of Suwon, Suwon, Gyunggi, South Korea)
ABSTRACT This paper introduces the PDT (Pulse Discharge Technology) piling method. The PDT piling method is to install in-situ a pile using electrical power so called Pulse power. Since this piling technique can make not only a bore hole to be expanded but also the ground to be improved by compaction, the pile installed by PDT appears to be able to develop shaft and end bearing capacity efficiently. In this study, we introduce a coefficient of expansion. In order for quantitative evaluation of the relation between pulse power and ground expansion a series of in-situ tests were conducted. In the tests, we divided soil conditions into several groups by constituents and the number of blows in the standard penetration test, N. The tests were carried out on various numbers of pulse discharge. As a result, it was concluded that the coefficient of expansion appeared to increase with an increase of the number of discharge and with a decrease of the number of blows, N. In addition, the coefficient of expansion appeared to differ from one position to another even though having the same N value. INTRODUCTION Since 1990s the piling technique, in which a precast pile is installed in the ground after boring, has been widely used in Korea especially in urban area(Lee et al, 2003). Even though this technique induces much less vibration and noise than pile driving, it has several disadvantages as following. First, the ground disturbance is inevitable during boring and it gives rise to the reduction of shaft resistance. In general, it has been known that the bearing capacity of a bored pile is taken by shaft resistance up to 60%. Such a shaft resistance is, however, far smaller than that of a driven pile due to the ground disturbance and stress release (Van Weele, 1988; DeBeer, 1988).
- Asia > South Korea (0.29)
- North America > United States (0.28)
Chemical And Physical Factors Influencing Behavior of Sodium Silicate-Cement Grout
Chun, Byung-Sik (Department of Civil Engineering, Hanyang University Seoul, Korea) | Yang, Hyung-Chil (CGM Corp. Seoul, Korea) | Park, Duk-Hyum (Department of Civil Engineering, Hanyang University Seoul, Korea) | Jung, Hyuk-Sang (Department of Civil Engineering, Hanyang University Seoul, Korea)
ABSTRACT This paper evaluates the influence of the additive on the compressive strength of the sodium silicate-cement grouts. When not using any additive, the compressive strength of silicate-cement grout homogel showed limited increase. It is estimated that complex salts (Na2O․ 3SiO2․ CaSO4․ H2O) were produced by the sodium silicate and the plaster retard the hydration of cement. The strength of the homo-gel increased significantly when using Sodium TripolyPhosphate as the additive. The strength is further increased when using the Circulation Grinding-Mixing method, which reduces the particle size of cement from 100-150 μm to 50-100 μm. In addition to laboratory tests, in-situ tests were performed to characterize the influence of the grout on the ground permeability. The test results indicated that the grouting significantly reduces the permeability of the ground. INTRODUCTION Since 1980 it is applied in South Korea and Japan, the age compressive strength of LW grouting was lower than data (refer to fig. 2). Thus, it was investigated into effect of concentration of sodium silicate on strength of Homo-gel when it varies the content of the sodium silicate in A solution 150 ℓ, 200 ℓ, 250 ℓ and fix the content of the cement is 200 kg in B solution. When the cement hydrate (calcium hydroxide) was 20% of cement weigh and the Molar Ratio was less than 1.0, the strength of the Homo-Gel was not higher than 5 kg/cm within 3 days. The results showed that Calcium Aluminate and Ferrite Complex Salts(Lea, 1971)and sodium hydroxide(NaOH) made cement hydrate delay. When sodium silicate gel, much calcium hydroxide which is essential to crystallization of a particle of cement is used. Based on calcium hydroxide poverty, the strength was not revealed(Yone kura et al., 2000).
- Asia > South Korea (0.35)
- Asia > Japan (0.25)
ABSTRACT Application of information technologies raises interest to preparation of high-qualified experts, quality management in operation of marine structures. Theoretical positions, principles of functioning, an assumptions and restrictions of decision system are given. Identification of problem area is carried out. Requirements of reliability, efficiency, protection of the information are provided. Methods and means of gathering and transfer of the information, a quality monitoring of the input information, language of inquiries, menu, helps, etc. are described. Graphic interpretation of structure of base of knowledge is given, the features of structure caused by character of tools are described, dependencies of factors the examinations connected with indistinct or probabilistic nature of knowledge are proved. The generalized reliability of offshore structures is determined by multiplication of physical, functional and external wear factors. The three stages of formation of information cone from raw data to information and then to synthesis of knowledge are considered. On every stage the cognitive maps are developed for three levels (meta-, macro- and microlevel). INTRODUCTION According to Federal program of water transport renovation up to 2010 the cargo turnover will be increased on 82% from 182 to 332 mln. t. There are 22 ports on Russia Far East from Posyet harbor to Tiksi port. The harbour structures need in investments accounting for development of offshore projects, exploration of Siberia and Yakutiya resources and usage of North transport route. At the present time the main problems are definition of wear and development of design procedures which are taking into account change of reliability during operation. Numerous defects of designs because of errors of designers and builders have turned with the course of time in critical ones.
Topographical Change of the Sandbar And Estimation of Suspended Solid Flux In the Nakdong River Estuary, Korea - Focused On Jinudo -
Lim, Sung-Pil (Department of Ocean Engineering, Pukyong National University) | Lee, In-Cheol (Department of Ocean Engineering, Pukyong National University) | Na, Won-Bae (Department of Ocean Engineering, Pukyong National University) | Kim, Heon-Tae (Department of Ocean Engineering, Pukyong National University) | Yoon, Han-Sam (Research center for Ocean Industrial Development, Pukyong National University Busan, Korea)
ABSTRACT In this study, to establish a countermeasure from marine casualties as a basic study for long-term prediction of topographical change around Jinudo in the Nakdong river estuary, Korea, spatio-temporal topographical change monitoring and Suspended Solid (SS) net flux estimation were carried out. From the result of monitoring, the annual mean ground level and deposition rate were estimated about 158.8 mm and 0.431 mm/day, respectively. Moreover, the depth averaged values of the latitudinal and longitudinal SS net fluxes during spring tide were approximately 6.0 times higher than those during neap tide. INTRODUCTION It is difficult to predict for environmental change in river estuary because this zones undergo constant changes due to the interaction between marine and fluvial systems. The zones in coastal area such as the tidal flat and salt marsh, is gradually decreased and changed due to large scale of coastal development projects, land reclamation, dike construction, and large amounts of soil dredging and so on (Tonis et al., 2002; van der Wal et al., 2002). The Nakdong river estuary, Korea, is located in the south-eastern part of Korea, is very famous for the largest Asian habitat for migratory birds. However, this estuary is suffering from the changes in the water circulation and topographical changes caused by the generation and migration of sandbars. The Suspended Solid (denoted as SS) originates from the materials such as clays, nutrients, polluted organic matters, and heavy metals. The transport of SS in shelf seas attracts more and more attention of scientists from different disciplines, as it plays an important role for many processes in the marine environment, not only for marine geology but also for the marine ecosystem (Jiang et al., 2004). As a result, many experiments have been undertaken to analyze topographical change.
- Energy > Oil & Gas > Upstream (1.00)
- Water & Waste Management > Water Management > Lifecycle > Treatment (0.81)
ABSTRACT The paper focuses on the experiment analysis and theory prediction of the resistance performance of large WPC (Wave-piercing Catamaran). The wave-making resistance is predicted by means of linear wavemaking resistance theory, and the viscous resistance is predicted based on Boundary Layer Theory. High precision is accomplished in certain velocity range for the WPC. Through changing the distance between the hulls, the wave-making interference of the two hulls is studied both in theory and experiment. By test in ship model tank, the practicability and reliability of the theory method is verified. The theory prediction of the resistance of WPC agrees well with the test result. INTRODUCTION The form of WPC experiences a few changes, and now goes to large and high speed. In 1983, the experiment boat built by INCAT is in fact a catamaran which takes out the upper part above waterline and installs two pillars to connect with the super structure. In 1986, INCAT modified the above solution. The fore and aft pillars on each side are changed to a single pillar. The hull and the pillar are smoothly connected with a piercing part on the fore hull. And the bottom of upper main body changed to V-type. Thus the WPC is easy to sail through waves with little resistance and better sea-keeping capacity. After 2000, the WPC installed self-controlling fin on fore, foil on the side and controllable plate on aft to reduce trim. The sea-keeping capacity improved greatly. As for other companies, the multi-hull company AMD of Australia carried out a series of experiments of WPC model in Australia and Holland, and NKK of Japan carried out research on connecting bridge with thin wall on WPC. In our country, the research on WPC starts from the end of 80s in the last century.
Study On Ductile Property of Corroded Reinforced Concrete Beam
Fan, Fang Ying (Institute of Road and Bridge Engineering, Dalian Maritime University & State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, Liaoning, China) | Hu, Qiang Zhi (State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, Liaoning, China)
ABSTRACT Ductility of corroded doubly reinforced concrete beam sections with a range of reinforcement corrosion and concrete degradation was studied. The ductility of reinforced concrete beams corroded by sulfate (SCRCB), in which the normal assumptions of plane section behavior held true, and chloride (CCRCB), in which the normal assumptions of plane section behavior did not hold true, was discussed. Based on mechanical tests on the corroded beams, the section analysis method and fractal theory were applied to study the ductility of corroded beams. A simplified expression is proposed to predict the ductility factor for corroded beams. A relationship between the fractal dimension and the ductility factor of the beam was found. INTRODUCTION To survive severe earthquakes, structures designed to the level of seismic loading recommended by codes need to be capable of ductile behavior at the critical sections while undergoing horizontal displacements in the inelastic range (Park, 1988). Reinforced concrete is one of the most durable construction materials. However, field surveys indicated that owing to various corrosion effects, many reinforced concrete structures exposed to aggressive environments (e.g. marine environment, chemical environment, etc.) have shown early deterioration including sudden failures. This indicates that corrosion will result in the degradation of the ductility of the RC member, and the failure mode of the corroded reinforced concrete (CRC) member will change from ductile to brittle. Such brittle failures will affect the load capacity of the structure, leading to possible casualties and huge financial loss. With the gradual increase of corrosion loss worldwide, the durability of RC structures in aggressive environments has become and will long be a research concern. Recently, large numbers of experiments have been performed to study the mechanical properties of CRC members (including CRC beams and columns) (Ballim, 2003; Yoon 2000).
- Geology > Structural Geology > Tectonics > Plate Tectonics > Earthquake (0.54)
- Geology > Mineral > Sulfate (0.35)
- Materials > Construction Materials (1.00)
- Construction & Engineering (1.00)
Design Code Calibration of Coastal Defences Against Typhoon Attacks For Nuclear Power Plant
Liu, Defu (Disaster Prevention Research Institute, Ocean University of China, Qingdao, Shandong, China) | Pang, Liang (College of Engineering, Ocean University of China Qingdao, Shandong, China) | XIE, Botao (College of Engineering, Ocean University of China Qingdao, Shandong, China) | Jiang, Hao (College of Engineering, Ocean University of China Qingdao, Shandong, China) | Han, Fengting (College of Engineering, Ocean University of China Qingdao, Shandong, China) | Yu, Yifa (Ocean University of China Qingdao, Shandong, China)
ABSTRACT With the global warming and sea level rising, it is widely recognized the increasing tendency of typhoon occurrence frequency and intensity. The increasing typhoon disaster and severe consequences lead us to make a design code calibration of coastal defense against typhoon attacks on nuclear power plant. This paper discussed the reasonability of definitions about "probable maximum typhoon", "probable maximum storm surge" in nuclear safety regulations of China and made some design code calibration by using our proposed Double Layer Nested Multi-objective Probability Model (DLNMPM). INTRODUCTION In recent years some typhoon and hurricane disasters brought significant losses of life and properties to South Korea, China and USA, such as Typhoon Maemi in 2004, Typhoon Rananim and Hurricane Ivan in 2004, Hurricane Katrina and Rita in 2005, Typhoon Saomai and Bilis in2006, Typhoon Sepat and Wipha in 2007, et al. In China, three nuclear power plants have been built along coasts of Guangdong and Zhejiang provinces since 1980s. Some of them have operated. It is estimated in "2007China Long Term Nuclear Power Plan" that, before 2020 about 450 billion RMB will be invested along 6 coastal provinces for increasing 23 million kilowatt nuclear electric energy. With global warming and sea level rising, the frequency and intensity of typhoons and typhoon induced disasters have been increasing. All the coastal areas of nuclear power plants are menaced by typhoon disasters. So calibration of typhoon disaster prevention criteria is necessary for existed nuclear power stations and nuclear power plant on planning. In "China Nuclear Safety Regulations (HAF101, HAD101/09~11)", some vague definitions should be discussed and endowed probability characteristics by using statistic analysis. In this paper, one built nuclear power plant engineering along coast of South China Sea was taken as example for code calibration.
- North America > United States (1.00)
- Asia > China > Zhejiang Province (0.24)
- Asia > China > Shandong Province (0.15)
Critical Thermal, Corrosion And Material Issues Related to Flowline Pipe-in-Pipe (PIP) Systems
Jukes, Paul Jukes Paul (J P Kenny, Inc / IONIK Consulting Houston, TX, USA) | Singh, Binder (J P Kenny, Inc / IONIK Consulting Houston, TX, USA) | Garcia, Jose (J P Kenny, Inc / IONIK Consulting Houston, TX, USA) | Delille, Francois (J P Kenny, Inc / IONIK Consulting Houston, TX, USA)
ABSTRACT The common method of achieving enhanced thermal insulation performance of flowlines (U values of 1.0 W/m2K, or less) requires a ‘Pipe-In-Pipe’ (PIP) insulation system, in which the inner pipe carrying the fluid is encased within a larger outer pipe separated by an annulus insulation material. However, with all PIP systems it is important to ensure that the structural integrity is maintained for both installation and operational loads for each of the PIP components (thermal insulation, linepipe, centralisers, waterstop seals, and loadshares). The temperature of the internal contents of a PIP system can have a significant effect on the long term degradation and performance of materials. It is not uncommon for recent designs of pipelines to be considered for temperatures up to 350°F (177°C). Also it is important to ensure integrity for the entire life of the project, and that undesirable degradation of the thermal and structural performance does not occur. The effects of temperature on the PIP components are discussed within this paper. Various insulation materials are considered and these consist of mineral wools, polyurethane foam, granular or microporous materials, ceramics and Aerogels. Annulus related corrosion integrity issues including monitoring, inspection and on-going degradation and aging management are addressed. Performance of insulation in terms of thermal, heat transfer and effects of corrosion under wetting conditions and cathodic protection at the field joints will also be considered. The new technology presented in this paper is; a discussion into the critical aspects of testing PIP components for high temperature applications, a critical evaluation of different thermal insulation materials, mechanisms of MICC "Microbially Influenced Crevice Corrosion" and the hidden annular "Corrosion under Insulation" for pipelines, and inspection methods. Hence, this paper discusses key issues associated with PIP systems in terms of the structural integrity, corrosion and material integrity with regards to the PIP components.
- North America > United States (0.28)
- North America > Canada (0.28)
- Research Report (0.34)
- Overview > Innovation (0.34)
- North America > Cuba > Gulf of Mexico (0.89)
- Europe > United Kingdom > North Sea (0.89)
- Europe > Norway > North Sea (0.89)
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- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Piping design and simulation (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
Application of Grouting the Sea-Crossing Bridge Foundation In the Busan-Geoje Fixed Link
Jeong, Gyeong- Hwan (Dong-A Geological Engineering Co., Busan, South Korea) | Park, Chan-Woo (Dong-A Geological Engineering Co., Busan, South Korea) | Kwon, Jin-Wook (Dong-A Geological Engineering Co., Busan, South Korea) | Kim, Jae-Hwan (Dong-A Geological Engineering Co., Busan, South Korea) | Kim, Chang Hwan (Construction Dept. Daewoo E&C Co., Seoul, South Korea) | Jeong, Sang-Kyoon (Construction Dept. Daewoo E&C Co., Seoul, South Korea)
ABSTRACT During construction of a sea-crossing bridge grouting was used to fill densely the space between the bottom of caisson and the ground. This grout mixture was mixed with anti-washout admixture after locating accurately the pre-cast caisson on three concrete landing pads. This method differs significantly from the costly conventional method, for bridge foundations offshore, where concrete is placed in situ after excavating inside of a temporary concrete coffering wall. To verify the grouting method in advance, the full-scale field tests were performed twice on land. After identifying the fluidity of the grout material to be filled, finding some possible problems with the main construction and revising the original design, the main construction has been continuing successfully with 20 caissons completed to date. The purpose of this paper is to introduce for the first time in Korea the grouting method including the automatic and the manual monitoring system based on the main construction of the caisson foundation. INTRODUCTION The Busan-Geoje Fixed Link, total length of 8.2km, in extension of the 58th local rode connected Gaduk island, Busan to Jangmokmyon Geoje, Gyongnam Province, consists of a cable stayed bridge and an immersed tunnel. The bridge, total length of 4,219.5m, consists of a cable stayed bridge, which is planed to be built between primary temporary sea route LOT2, second temporary sea route LOT1 and a junction bridge as shown in Fig.3. Beside the main tower, all parts (caisson, pier, upper slab etc) were planed to be pre-cast on land and to be moved to the site and then assembled step-by-step. As showed in Fig 4 and Fig.5, 23 caissons (LOT1 for 12, LOT2 for 11) were located on three landing pads and the space beneath the caisson was filled with the anti-washout grout to unify the caisson and the space.
ABSTRACT Pipeline spans occur when a flowline is laid on a rough seabed and/or when upheaval buckling of the flowline is generated due to thermal expansion. This not only results in static and dynamic loads on the flowline at the span section, but also generates Vortex Induced Vibration (VIV) responses. The phenomenon, if not predicted and controlled properly, will result in significant damage to the pipeline integrity. The span issues can be very complicated to analyze due to the long span lengths, a rough seabed, the large number of spans, and multi-span interactions. In addition, the complexity can be more onerous and challenging when soil uncertainty, unknown residual lay tension, and variation of spans from year to year is considered in the analysis. The methodology discussed in this paper will not only highlight the most important areas in the assessment of the complex spans but also provide many technical details. The new methodology presented in this paper includes the following: The initial data assessment for seabed and wave/current is discussed and certain assumptions are made for a conservative design; Understanding of DNV design code and implementing it using advanced numerical FE tools is an evaluation basis for span analysis; In the FEA modeling, many details are discussed such as model length and concrete induced SCF (Stress Concentration Factor) at field joints; Certain sensitivity studies for concrete degradation, survey accuracy, and soil stiffness are also discussed to ensure the most conservative cases are captured. Special cares are mentioned in the ULS check for wave/current data (extreme or significant) and wave load application to interacting spans; In addition, an example of fatigue calculation for an interacting span is provided. The approach used in the methodology brings a useful guideline to the span analysis, especially in the complex span conditions.