• Geomechanics and Engineering
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• v.13 no.6
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• pp.1011-1025
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• 2017

The geological conditions surrounding the Jijiapo Tunnel of the Three Gorges Fanba Highway project in Hubei Province are very complex. In this paper, a 3-D physical model was carried out to study the evolution process of filling-type fracture water inrush and mud gush based on the conditions of the section located between 16.040 km and 16.042 km of the Jijiapo Tunnel. The 3-D physical model was conducted to clarify the effect of the self-weight of the groundwater level and tunnel excavation during water inrush and mud gush. The results of the displacement, stress and seepage pressure of fracture and surrounding rock in the physical model were analyzed. In the physical model the results of the model test show that the rock displacement suddenly jumped after sustainable growth, rock stress and rock seepage suddenly decreased after continuous growth before water inrushing. Once water inrush occured, internal displacement of filler increased successively from bottom up, stress and seepage pressure of filler droped successively from bottom up, which presented as water inrush and mud gush of filling-type fracture was a evolving process from bottom up. The numerical study was compared with the model test to demonstrate the effectiveness and accuracy of the results of the model test.

• Earthquakes and Structures
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• v.26 no.4
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• pp.261-267
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• 2024

With the increase in the exploitation depth of offshore oil and gas, it is possible to control the global buckling of deep-sea pipelines by the snake lay method. Previous studies mainly focused on the analysis of critical buckling force and critical temperature of pipelines under the snake-like laying method, and pipelines often suffer structural failure due to seismic disasters during operation. Therefore, seismic action is a necessary factor in the design and analysis of submarine pipelines. In this paper, the seismic action of steel pipes in the operation stage after global buckling has occurred under the active control method is analyzed. Firstly, we have established a simplified finite element model for the entire process cycle and found that this modeling method is accurate and efficient, solving the problem of difficult convergence of seismic wave and soil coupling in previous solid analysis, and improving the efficiency of calculations. Secondly, through parameter analysis, it was found that under seismic action, the pipe diameter mainly affects the stress amplitude of the pipeline. When the pipe wall thickness increases from 0.05 m to 0.09 m, the critical buckling force increases by 150%, and the maximum axial stress decreases by 56%. In the pipe soil interaction, the greater the soil viscosity, the greater the pipe soil interaction force, the greater the soil constraint on the pipeline, and the safer the pipeline. Finally, the pipeline failure determination formula was obtained through dimensionless analysis and verified, and it was found that the formula was accurate.

• Ocean and Polar Research
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• v.27 no.3
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• pp.251-263
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• 2005

In order to study changes in the marine ecosystem of the East China Sea derived by the global warming and construction of the Three Gorges Dam in the middle of the Changjiang, temperature, salinity, nutrients, and chlorophyll-a were studied intensively in the northern part of the East China Sea during the summer of 2003 and spring of 2004. According to the previous studies, the upwelling of the Kuroshio Current and the Changjiang resulted in a major inputs of nutrients in the East China Sea, but these two inputs may not contribute gently to a build up of nutrients in the northern East China Sea. In spring, relatively high concentrations of nitrates and phosphates were observed in the western part of the study area, which resulted from the supply of high concentrations of nutrients showing up in the surface waters as a result of vertical mixing from the ocean bottom. The concentrations of nitrates and phosphates observed in summer were lower than those in spring, since the surface waters were well stratified by the larger discharge of fresh water from the Changjiang in summer. The surface nitrate/phosphate ratios ranged from 1.3 to 16 in spring and from 1.1 to 15 in summer and were lower than the Redfield ratio of 16, indicating that the growth of phytoplankton is limited by nitrogen. This results are contrary to the previous results, in which the growth of phytoplankton was limited by phosphate in the East China Sea. The reason for this contrary result is that most nutrients in the surface waters are supplied by vertical mixing from the bottom waters with low nitrate/phosphate ratios, not directly influenced by the Changjiang with high nitrate/phosphate ratios. The depth-integrated chlorophyll observed in summer was similar to the previous results, but those measured in spring were almost twice as high as those found in previous results. The depth-integrated chlorophyll in spring was higher than that of summer, which results from high concentrations of nitrates and phosphates in the surface waters in spring due to active vertical mixing.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.3
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• pp.139-153
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• 2014

This study contemplates the utopian landscape recognized by the scholars with twenty three pieces of 'travel record'. Consequently, five key words - Mureungdowon(武陵桃源), Byeolcheonji(別天地), Dongcheon(洞天), Chonghakdong, Eungeoji(hermitage) - are chosen for comprehending the utopia and their landscape characteristics are organised as follows. Mureungdowon in Jirisan Mountain which the scholars dreamed of is a flatland with the full energy for local vegetation and domestic animals in the mysterious and deep gorge. This utopia eventually reflects the rural landscape. Byeolcheonji is a utopia combining the concept of a fairyland and beautiful scenery. The scholars also used the term 'Dongcheon' for naming the enclosed landform which is suitable for seclusion and defining the some areas of beautiful scenery. Cheonghakdong, which is set only in Jirisan Mountain, has been formed by the stone scenery of gorges and Buril waterfalls around the whole area of Burilam Hermitage, the vegetation scenery of pine trees and bamboos with the legend of Choi Chiwon and his engraved inscription on a rock. Adding to the utopia passed down, the scholars perceived the village with geographical features with back to the mountain and facing the water, the river practising the trade, the flatland enclosed by bamboo forests, the vegetation mainly consisting of fruit trees and beautiful scenery as the utopia realized on earth. It is equivalent to the world of human beings laboring appropriately and living in Mother Nature. As mentioned above, this study has significance for apprehending the relevance between the culture of strolling in the mountains by the scholars of Joseon Dynasty and the fairyland and explaining the various traditional utopias from the inherited concepts from China to the naturalized realistic utopia.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.3
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• pp.133-142
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• 2009

In order to understand the present environmental condition and future impingement of Changjiang(Yangtze River) outflow upon the adjacent seas after the scheduled completion of the Sanxia (Three Gorges) Dam in 2009, we tried to estimate the mixing ratios among surface waters of three end-members: Changjiang Water (CW), Kuroshio Water (KW), and East China Sea Water (ECSW) using $^{228}Ra/^{226}Ra$ activity ratio and salinity as tracers. Water samples were collected from 32 stations in November 2005 (R/V Tamgu 3), from 20 stations in July 2006 (R/V Ocean 2000) and from 17 stations in August 2006 (R/V Ieodo) in the northern part of the East China Sea. Radium isotopes in ~300 liters of surface seawater were extracted onboard by filtering through manganese impregnated acrylic fibers and following coprecipitation as $Ba(Ra)SO_4$. Activities of radium isotopes were determined by a high purity germanium detector. Results show that the fraction of CW was in the range of 1-23% in the study area, while KW was in the range of 0-30 % and ECSW 58-100 %. The eastward plume of Changjiang outflow, commonly observed in satellite images during summer and also displayed by the eastward-decreasing CW fraction in this study, could be attributed to Ekman transport caused by the SE monsoon prevailing in this region during summer. Results of this study showed that in the drought season, there was a little or no fraction of CW in the study area. Concentration of dissolved inorganic nitrogen (DIN) showed strong positive relationship with the fraction of CW, suggesting Changjiang as the major source of nitrogen. The mixing curve of DIN indicates the removal of nitrate by biological uptake during the mixing of CW with ambient seawater in the study area.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7459-7466
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• 2013

Background: Some 60 years after introduction of the Papanicolaou smear worldwide, cervical cancer remains a burden in developing countries where >85% of world new cases and deaths occur, suggesting a failure to establish comprehensive cervical-cancer control programs. Effective interventions are available to control cervical cancer but are not all affordable in low-income settings. Disease awareness saves lives by risk-reduction as witnessed in reducing mortality of HIV/AIDS and smoking-related cancers. Subjects and Methods: We initiated a community-based awareness program on cervical cancer in two low-income Muslim Uyghur townships in Kashi (Kashgar) Prefecture, Xinjiang, China in 2008. The education involved more than 5,000 women from two rural townships and awareness was then evaluated in 2010 and 2011, respectively, using a questionnaire with 10 basic knowledge questions on cervical cancer. Demographic information was also collected and included in an EpiData database. A 10-point scoring system was used to score the awareness. Results: The effectiveness and feasibility of the program were evaluated among 4,475 women aged 19-70 years, of whom >92% lived on/below US$1.00/day. Women without prior education showed a poor average awareness rate of 6.4% (164/2,559). A onetime education intervention, however, sharply raised the awareness rate by 4-fold to 25.5% (493/1,916). Importantly, low income and illiteracy were two reliable factors affecting awareness before or after education intervention. Conclusions: Education intervention can significantly raise the awareness of cervical cancer in low-income women. Economic development and compulsory education are two important solutions in raising general disease awareness. We propose that implementing community-based awareness programs against cervical cancer is realistic, locally affordable and sustainable in low-income countries, which may save many lives over time and, importantly, will facilitate the integration of comprehensive programs when feasible. In this context, adopting this strategy may provide one good example of how to achieve "good health at low cost".

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.189-206
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• 2015

The present study was conducted to investigate the oceanic characteristics of the northern East China Sea through identification of long-term variation patterns of oceanic environment factors, for the objective of gaining understanding of oceanic environment characteristics of the northern waters of East China Sea, which closely influence the oceanic environments of waters nearby South Korea. The study methodology included the use of oceanographic data (water temperature, salinity, dissolved oxygen, nutrients, and chlorophyll-a) on the northern East China Sea from the Korea Oceanographic Data Center (KODC), collected by season for 20 years between 1995 and 2014. Moreover, for the study on the distribution of nutrients, chlorophyll-a. The main water masses that affected the northern East China Sea during the study period were classified as Changjiang diluted water (CDW), Tiawan current warm water (TCWW), Yellow Sea cold water (YSCW), and Kuroshio source water (KW). The forces of CDW and TCWW that forms on the surface and sub-surface layers had weakened for 20 years and the force of KW that forms on the intermediate layer showed a distinctively decreasing trend. However, YSCW showed a trend of expanding its force. Phosphate and silicate exhibited a decreasing tendency and phosphate showed a pattern of being depleted on the surface layer after 2009. It is determined that one of the reasons for this is the concentration of nutrients introduced through CDW and TCWW being too low. The concentration of chlorophyll-a exhibited an increasing tendency during the study period, the reasons for which are determined to be the influences of increase in water temperature, supply of nutrients via YSCW, and increases in light transmission from decrease in suspended solid due to the construction of the Three Gorges Dam.