DEStech Transactions on Environment, Energy and Earth Sciences最新文献

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Causes and Stability Evaluation of a Large Landslide in Nanjing 南京某大型滑坡成因及稳定性评价
DEStech Transactions on Environment, Energy and Earth Sciences Pub Date : 2019-10-22 DOI: 10.12783/dteees/eece2019/31550
Wen Gu, Faming Zhang, P. Ge, Zinan Li, Song Chen
{"title":"Causes and Stability Evaluation of a Large Landslide in Nanjing","authors":"Wen Gu, Faming Zhang, P. Ge, Zinan Li, Song Chen","doi":"10.12783/dteees/eece2019/31550","DOIUrl":"https://doi.org/10.12783/dteees/eece2019/31550","url":null,"abstract":"Through the geological survey in the field, the development characteristics of landslide landslides are systematically analyzed. Through the simulation of the influence of different factors on the stability, it is determined that the main reason for the sliding of the landslide is the heavy rainfall and the slope cutting, which reveals the geological origin and mechanical origin of the landslide body. The limit equilibrium theory is used to analyze the stability and residual sliding force of different potential sliding surfaces. For the three-row anchored anti-slide pile + profile prestressed frame anchor cable + drainage system emergency reinforcement measures adopted by the owner, the stability factor of the landslide body is demonstrated after emergency reinforcement. The research shows that although the corresponding reinforcement measures are taken, the landslide body still does not meet the safety requirements, and further deep reinforcement measures must be taken for treatment. The research results provide a theoretical basis for the reinforcement design of the landslide body. Introduction Landslide hazard is one of the most widespread geological hazards in steep slope area The number of landslides accounts for more than 70% of the total disasters, and the casualties caused by large landslides account for about 70% of the total casualties [1]. Landslide prevention and control engineering research has also become one of the hot spots in engineering research [2]. Since 1982, more than 70 landslides, avalanches and mudslides have occurred on both sides of the reservoir area. [3]. In June 2015, due to heavy rainfall, a large-scale landslide occurred on the south side of a mountain in Nanjing, which brought great security risks to the ecological security of the scenic spot and the Alila Hotel under construction, therefore it is necessary to conduct engineering geological research on the affected areas. Engineering Geological Conditions of Landslides Meteorology and Hydrology The rainfall in Nanjing is abundant. The annual precipitation is 1200mm, the annual average precipitation is 1106mm, and the season with the most precipitation is July, with 494.5mm; the season with the least precipitation is February, with only 7.7mm. The precipitation in June measured by the Nanjing National Climate Observatory in 2016 has reached 625.5mm, which not only far exceeds the June historical record, but also broke the historical record of July 1931. Topography The landslide body is located in the south branch of the western section of the hills of Ningzhen. It belongs to the Yangqiugang landform of Ningzhen, the low hilly and landform unit, and the terrain is undulating. The trend of the mountain is generally northwest-south-east, and the mountain vegetation is flourishing. The elevation of the east and west peaks is 247.5m and 201.6m. There is an east-west ridge on the top of the mountain, which is slightly saddle-shaped. 177 Physical and Mechanical Indicators","PeriodicalId":11324,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74279971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Study on the Preparation of New Wall Materials from Urban Construction Waste 利用城市建筑垃圾制备新型墙体材料的研究
DEStech Transactions on Environment, Energy and Earth Sciences Pub Date : 2019-10-22 DOI: 10.12783/dteees/eece2019/31546
Zhaoheng Guo, Shuang Shang, K. Lan, Ze-shan Li, Weitao He, Wen-juan Shen, Jian-fen Li
{"title":"Study on the Preparation of New Wall Materials from Urban Construction Waste","authors":"Zhaoheng Guo, Shuang Shang, K. Lan, Ze-shan Li, Weitao He, Wen-juan Shen, Jian-fen Li","doi":"10.12783/dteees/eece2019/31546","DOIUrl":"https://doi.org/10.12783/dteees/eece2019/31546","url":null,"abstract":"Graphene oxide (GO) has considerable application value in the concrete field, but its poor dispersion performance in cement restricts its adhibition. In this study, GO and water reducer composites (S-GO) obtained by ultrasonic dispersion treatment were used to promote the dispersion property in cement, meanwhile, the effects of water reducer species and GO dosage on mechanical properties and microstructure of recycled wall materials were investigated. By comparing the effects of four different water reducers, the greatest was polycarboxylate superplasticizer (PCs). When the optimal dosage of GO composite (PGO) was 0.06%wt, the compressive and flexural strength of the concrete specimens after curing for 28 days increased by 30% and 26% compared with the control sample. SEM results show that the hydration products of cement are evenly distributed and arranged in an orderly manner, which were the critical factors for improving mechanical property of cement. The study provided a reliable method for enhance the mechanical performance of recycled wall materials. Introduction With the development of China's economy, science and technology, the construction industry is also booming. A large amount of construction waste is generated every year, which accumulates into a mountain and occupies a large amount of land resources. Moreover, landfills often cause serious hazards and affect the normal life of citizens every year. It has become an urgent problem to break up and recycle construction waste. Lv S, professor of Shaanxi University of Science & Technology, conducted research on the template effect of GO on the formation of cement hydration crystals [1,2] . On the basis of this research, this experiment prepared high-performance wall materials by adding self-made GO composite materials into recycled aggregate of construction waste, and studied the influence of GO composite materials on concrete hydration products, microstructure and properties, laying a theoretical foundation for the establishment of structural model of recycled wall materials [3,4] .","PeriodicalId":11324,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84546779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Research and Development of Large-scale Environmental Wind Field Simulation Device for Fire Experiment of High-rise Building 高层建筑火灾试验大型环境风场模拟装置的研制
DEStech Transactions on Environment, Energy and Earth Sciences Pub Date : 2019-10-22 DOI: 10.12783/dteees/eece2019/31552
Hang Yin, Ya-qiang Jiang, Qingdong He, Longwang Tan
{"title":"Research and Development of Large-scale Environmental Wind Field Simulation Device for Fire Experiment of High-rise Building","authors":"Hang Yin, Ya-qiang Jiang, Qingdong He, Longwang Tan","doi":"10.12783/dteees/eece2019/31552","DOIUrl":"https://doi.org/10.12783/dteees/eece2019/31552","url":null,"abstract":"The research and development processing of a large-scale environmental wind field simulation device for fire experiment of high-rise building is introduced from 4 aspects as size and arrangement study of wind supply terminal, velocity design of wind supply terminal, structure design of large-scale device and final installation and commissioning. The simulated wind with the maximum speed of no less than 17m/s can be provided by 200 uniformly distributed ball spout jet diffusers in the region of 8 meters high and 4 meters wide. Introduction High-rise building fires often cause huge casualties and property losses. According to the NFPA report [1], U.S. fire departments responded to an estimated average of 14,500 reported structure fires in high-rise buildings per year in 2009-2013. These fires caused an average of 40 civilian deaths, 520 civilian injuries, and $154 million in direct property damage per year. Generally, the environmental factors, especially the environmental wind field, will have a huge impact on the fire behavior. Therefore, when a fire experiment of high-rise building is performed by researchers, the real fire scenario cannot be well reflected if the effect of environmental wind field is ignored. However, existing environmental wind field simulation devices are mostly used in the field outside the fire science, such as hurricane simulation [2], aerodynamic wind tunnel test [3], wind load simulation [4] and so on. Not only that, the fewer environmental wind field simulation devices applied in fire research still have some limitations in fire experiment of high-rise building that the area of wind supply terminal is insufficient and the angle of airflow is unmodifiable [5,6]. For above problems, a large-scale environmental wind field simulation device is developed to realize simultaneous adjustment on both area and angle of supply airflow for fire experiment of high-rise building. Study on Size and Arrangement of Wind Supply Terminal Based on CFD The effect of environmental wind field simulation device is greatly influenced by the type and arrangement of wind supply terminal. Based on the comprehensive comparison of all kinds of wind supply terminals, the ball spout jet diffuser is chosen because of the long air delivery and adjustable angle in all directions in within 30 degrees. Figure 1. Arrangement of wind supply terminal for 4 cases.","PeriodicalId":11324,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77504089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Research on the Entrance Space of Tibetan Temple Buildings 藏族寺庙建筑入口空间研究
DEStech Transactions on Environment, Energy and Earth Sciences Pub Date : 2019-10-22 DOI: 10.12783/dteees/eece2019/31569
Dong-pio Che, Xin Chen
{"title":"Research on the Entrance Space of Tibetan Temple Buildings","authors":"Dong-pio Che, Xin Chen","doi":"10.12783/dteees/eece2019/31569","DOIUrl":"https://doi.org/10.12783/dteees/eece2019/31569","url":null,"abstract":"The entrance space of the Tibetan temple building serves as the “facade” of the entire building, which embodies the architectural style of the Tibetan temple. Based on the field investigation of temple buildings in Tibet, the paper analyzes the plane shape and decorative art of the entrance space, and summarizes the evolution of the plane shape of the entrance space and the characteristics of decorative art of the entrance space. Therefore, the paper contains analysis and inheritance of Tibetan traditional architectural culture for certain reference.","PeriodicalId":11324,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82703935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Study on the Freezing and Thawing Damage of Concrete Pavement under the Action of Deicing Agent 除冰剂作用下混凝土路面冻融损伤的研究
DEStech Transactions on Environment, Energy and Earth Sciences Pub Date : 2019-10-22 DOI: 10.12783/dteees/eece2019/31560
Qi Bo, Guang Shi, Liang Zou
{"title":"Study on the Freezing and Thawing Damage of Concrete Pavement under the Action of Deicing Agent","authors":"Qi Bo, Guang Shi, Liang Zou","doi":"10.12783/dteees/eece2019/31560","DOIUrl":"https://doi.org/10.12783/dteees/eece2019/31560","url":null,"abstract":"In the winter, large-scale passenger airports in northern China, aircraft deicing is a common job. This is because in the rainy and snowy weather in winter, the surface of the aircraft will freeze, and the aircraft is strictly forbidden to take off in the icing state. Therefore, there is a special de-icing platform in the airport to de-ice the aircraft. The deicing fluid containing chemical substances stays on the surface of the de-icing concrete, which will cause the concrete aggregate to peel off and crack, forming FOD and endangering flight safety. Therefore, this paper studied the properties of ethylene glycol deicing fluid and the freeze-thaw cycle damage test of concrete under the action of deicing fluid. The test results show that the low concentration deicing fluid has a greater damage to concrete freeze-thaw. In addition, the article uses finite element software to simulate the two-dimensional concrete frost heaving damage. The simulation results show that the damage propagation in the crack will be along the weak inner surface of the concrete, mainly along the concrete aggregate; under the same conditions, the influence of the depth of the crack on the concrete damage is greater than the impact of the crack width on the concrete damage.","PeriodicalId":11324,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82757349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Research on Solar Power Generation Disaster Relief Tent Based on Inflatable Structure 基于充气结构的太阳能发电救灾帐篷研究
DEStech Transactions on Environment, Energy and Earth Sciences Pub Date : 2019-10-22 DOI: 10.12783/dteees/eece2019/31523
B. Fan, Maoyuan Shi, Jiacheng Pang, Jiangqi Wang, Jianwu Wang
{"title":"Research on Solar Power Generation Disaster Relief Tent Based on Inflatable Structure","authors":"B. Fan, Maoyuan Shi, Jiacheng Pang, Jiangqi Wang, Jianwu Wang","doi":"10.12783/dteees/eece2019/31523","DOIUrl":"https://doi.org/10.12783/dteees/eece2019/31523","url":null,"abstract":"The local structure of disaster relief tent was analyzed by ANSYS. The deformation of inflatable column was basically consistent with the deformation of inflatable column after expansion, and the stress at different positions was also consistent with the basic size. The optimum ratio of height to width of arch was obtained to ensure the strength and stability of arch. At the same time, the optimal ratio of long axis to short axis of ellipse with small stress and strain was obtained. The suitable size was chosen to design the overall structure of the inflatable tent. The practical number and distribution mode of solar energy film was formulated, and the solar energy film was combined with tent. Finally, the inflatable structure tent with power generation function for disaster areas was obtained. Introduction In earthquake disasters, clothes and other materials were needed by the victims, and tents that could shelter the wind and rain were more needed in harsh environments [1].On May 12, 2008, a strong earthquake of magnitude 8.0 struck Wenchuan, China, requiring more than 3 million tents were erected in a few days. \"Water Cube\" stadium was the largest membrane structure project in the world at present, which means that domestic research on the materials and fabrication technology of inflatable membranes has gradually matured [2]. Inflatable membrane structure had been widely used in tent field [3]. Disaster relief tents were mainly used for temporary and short-term emergency relief. Most of the fabrics used were PVC or PU coated fabrics with poor air permeability or impermeability, which had poor warmth retention, thermal insulation and air permeability. Comfort was also a difficult problem in the design of tents in disaster areas. The existing disaster relief tents were heavy and inconvenient to transport. At the same time, the construction of disaster relief tents needs cooperation of many people to complete. Wind resistance of tents was mainly studied in the literature of new integral folding frame tent structures [4]; the feasibility of emergency tents and extension services from a spatial perspective were mainly studied in the literature of the design of emergency tents in post-disaster public space [5]; The design and research of inflatable tent [6] could reduce the difficulty of tent construction, and had the characteristics of lightness and convenient transportation. In the early stage of disaster relief, lighting was a big problem. . An inflatable tent with solar power could solve the problems of simple lighting difficulties and fast construction. Structural Design The inflatable structure of the tent was shown in Figure 1. Elliptical structure was adopted at the bottom and arch structure was used at the top as the tent skeleton [7]. The tent was composed of four parts: inside tent, outside tent and tent skeleton. The tent was equipped with solar power film,","PeriodicalId":11324,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90145256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Research and Application on Freeing from Pipe Stuck Technology of Large-diameter and Long-distance Pipe Jacking Construction in Complex Geology 复杂地质条件下大直径长距离顶管施工解卡技术研究与应用
DEStech Transactions on Environment, Energy and Earth Sciences Pub Date : 2019-10-22 DOI: 10.12783/dteees/eece2019/31561
Qing-jiang Wang, Yue Wang
{"title":"Research and Application on Freeing from Pipe Stuck Technology of Large-diameter and Long-distance Pipe Jacking Construction in Complex Geology","authors":"Qing-jiang Wang, Yue Wang","doi":"10.12783/dteees/eece2019/31561","DOIUrl":"https://doi.org/10.12783/dteees/eece2019/31561","url":null,"abstract":"Pipe jacking technology is mainly applied to road-crossing place where excavation is not applicable. So far, there is no mature experience in domestic being appropriate for long-distance and large-diameter pipe jacking passing through mountainous area with complicated geology, where obstruction problem like pipe stuck often happens [1] . This thesis does analyses on the reason for long-distance and large-diameter pipe jacking in mountainous area getting stuck and does discussion on freeing from pipe stuck. Combining with engineering examples, these methods have been put into practical application, which achieves good effects and socioeconomic benefits. It also provides guidance and reference for similar projects. Introduction Pipe jacking construction is a kind of non-excavation construction methods, which achieves pipeline, lay with on excavation or less excavation. With the aid of jacking force from jacking device in working well, pipe jacking construction overcomes friction of pipeline and surrounding soil, jacking pipelines into soil according to the designed gradient and direction and carries away the earth [2] . After the first section of pipe is jacked into soil, the second would be continued jacking. These pipe sections are produced in prefabricated field, which would be transported to engineering field, hanged into working well and jacked into the rock. Simultaneously do pipe jacking and micro shield operations on tunnel face on the front end of pipe section. With propelling forward, muck would be taken outside the tunnel by slurry. For the sake of reducing pipe jacking resistance, inject thixotropic anti-friction slurry on the back of tunnel pipe section so as to form slurry jacket of certain thickness thus leading pipe jacking to continue in the slurry jacket and reducing resistance. At the present stage, pipe jacking technology has become the main measure for no-dig construction of urban underground pipeline, which has been widely utilized in fields like drainage, sewage treatment, power pipeline, places being inconvenient for excavation, etc. Along with constantly accelerating of urbanization in our country, people keep high requirements on beautiful life, ecological protection and green construction. Keeping features of low noise, low pollution and low impact, pipe jacking construction is leaded to develop toward complex direction with large diameter, long distance, thick covering soil and complex curve [3] . While long jacking distance leads pipes to cross different stratums. When pipes encounter the weak stratum, jacking becomes difficult and even pipe stuck happens. On the basis of it, this thesis analyzes the reason for pipe stuck in pipe jacking operation, discusses methods for freeing from pipe stuck and does practical application. This provides certain practical experience for technology of extricating pipe from stuck in pipe jacking construction with large diameter, long distance and complex geology.","PeriodicalId":11324,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79079254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Policy Reforms of Biomass Power Generation Industry in China: Biomass CHP 中国生物质发电产业的政策改革:生物质热电联产
DEStech Transactions on Environment, Energy and Earth Sciences Pub Date : 2019-10-22 DOI: 10.12783/dteees/eece2019/31530
Liping Yan
{"title":"Policy Reforms of Biomass Power Generation Industry in China: Biomass CHP","authors":"Liping Yan","doi":"10.12783/dteees/eece2019/31530","DOIUrl":"https://doi.org/10.12783/dteees/eece2019/31530","url":null,"abstract":"China's biomass power generation industry has experienced more than 10 years of development, and under the new situation of clean heating policy, it is facing a good opportunity for the transformation and upgrading of CHP.A series of incentive policies issued by the Chinese government, such as financial subsidies and income tax relief, provide a good policy environment for the development of the biomass CHP industry. Private capital is the main force of China's biomass CHP investment. In order to broaden the financing channels of enterprises, the government encourages the listing of biomass CHP companies or the issuance of bonds. Biomass CHP has the characteristics of high efficiency, low carbon and energy saving. It helps to improve the utilization rate of biomass resources, control haze, build beautiful countryside and increase farmers' income. Introduction Global warming has attracted worldwide attention to greenhouse gas emissions, and the Kyoto Protocol stipulates the limits of greenhouse gas emissions from States parties. In order to achieve the emission reduction targets of the Kyoto Protocol, the development and utilization of renewable energy and the improvement of energy efficiency have been paid much attention by all countries. After the promulgation of the \"renewable energy law\" in 2006, China's biomass energy industry is developing rapidly. The main way to use it is biomass power generation. Biomass direct fired power generation projects are mainly concentrated in North China, Northeast China, central China and eastern China with abundant crop straw. The installed capacity accounts for about 94% of the total biomass fired power generation installed capacity in China. However, most of them only generate electricity without heating, resulting in the low efficiency of biomass power generation industry in China, especially the annual equivalent load hours averaging less than 5200 hours. Only 7 provinces have an annual equivalent load of more than 6000 hours, including Liaoning, Ningxia, Jiangsu, Shaanxi, Zhejiang, Guangxi and Guangdong. In 2017, the Northern Region's Winter clean heating Plan (2017-2021) created a good opportunity for biomass power generation to transform into biomass CHP. The aim of this paper is to present an overall policy framework based on the development process of biomass CHP in China. In addition, it also introduces the latest projects in order to realize the government's policy of cleaning and heating, including the overall situation, the development model and the main characteristics. In the end, it analyses the environmental and social benefits of the development of the biomass CHP project. Development Process of Biomass CHP in China","PeriodicalId":11324,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88510629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Surrounding Rock Pressure Analysis of Underground Station with Extra-large Section and Small Spacing 特大断面小间距地下车站围岩压力分析
DEStech Transactions on Environment, Energy and Earth Sciences Pub Date : 2019-10-22 DOI: 10.12783/dteees/eece2019/31557
Tao Liu, Xin Liu, L. Zhong, Hai-ou Wang, Jintong Gu
{"title":"Surrounding Rock Pressure Analysis of Underground Station with Extra-large Section and Small Spacing","authors":"Tao Liu, Xin Liu, L. Zhong, Hai-ou Wang, Jintong Gu","doi":"10.12783/dteees/eece2019/31557","DOIUrl":"https://doi.org/10.12783/dteees/eece2019/31557","url":null,"abstract":"The design and construction of underground station with extra-large section and small spacing is one of the difficult issues of concern of the civil engineering sector. Since the time is short, the theoretical research of underground station with extra-large section and small spacing is far behind the engineering practice. There has not been a unified understanding of the distribution rule of the station surrounding rock pressure, only with the means of numerical simulation study. In this paper, a small distance station of Chongqing rail transit is taken as the background, using the large finite element software MIDAS/GTS, a two-dimensional numerical model is established for analysis and calculation. Through respectively changing the different buried depth and spacing, the influence of the surrounding rock pressure from buried deep and spacing is studied and the basis is provided for the design and parameter optimization of the station lining structure. Introduction With the rapid development of urban rail transit, the large span and small distance tunnel has gradually increased. However, because of its short time, there is no unified understanding of the distribution of pressure and deformation of surrounding rock. At present, there are three main methods for solving geotechnical materials: exact solutions, numerical methods and test methods. The interaction between underground stations and surrounding geotechnical media under various dynamic and static loads is very complicated, and because geomaterials are mostly non-continuous and nonlinear materials, they cannot be accurately solved by a single function or equation. Only linear elastic systems with simple geometric shapes and material properties, and simple load patterns and boundary conditions can obtain more accurate answers. For an underground station with any geometric shape in a complex nonlinear rock mass, the mechanical analysis must be performed by means of computer numerical simulation[1]. The finite element method has become a powerful tool for geotechnical engineering applications. It is also a very effective numerical analysis method for the discretization of more complex continuum structures and the use of mechanical theory and computer technology to solve complex problems. Due to the complexity of the extra-large section and small spacing underground station, the relative theoretical research is lagging behind. At present, there are many researches on the construction methods of small-section tunnels with extra large sections[2-5]. Qihang Zhang studied the construction stability factors of small-section tunnels with extra large sections under complex conditions[6,7]. Zhang Li studied the stability control technology of surrounding rock of small clearance tunnel[8]. Some scholars have carried out research on the confining pressure of small clearance tunnels[9-11], but there are few studies on the surrounding rock pressure of small-section tunnels with extra large sections. At pr","PeriodicalId":11324,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88168166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Removal of Tetrachloroethene in Water with Nano Pd/Fe Bimetal Immobilized in Alginate Beads 藻酸盐微球固定化纳米钯铁双金属去除水中四氯乙烯的研究
DEStech Transactions on Environment, Energy and Earth Sciences Pub Date : 2019-10-22 DOI: 10.12783/dteees/eece2019/31545
Chien-ting Chen, Yi-Chu Huang
{"title":"Removal of Tetrachloroethene in Water with Nano Pd/Fe Bimetal Immobilized in Alginate Beads","authors":"Chien-ting Chen, Yi-Chu Huang","doi":"10.12783/dteees/eece2019/31545","DOIUrl":"https://doi.org/10.12783/dteees/eece2019/31545","url":null,"abstract":"In this study, nZVI, nPd/Fe and nPd/Fe-B particles were synthesized and used to remove PCE in solution to investigate the effects of several parameters such as the types of metal particles and their mass concentration. From the elemental mapping images of energy dispersive spectrometer (EDS), amorphous Fe and Pd were tightly integrated into the alginate matrix, which cannot be solely exfoliated from the whole composites. The results showed that the removal efficiency (r) and observed reaction rate constants (kobs) was the highest for nPd/Fe, followed by nPd/Fe-B and nZVI particles. Moreover, the larger the reductant dosage, the higher the r of PCE for nZVI, nPd/Fe, and nPd/Fe-B particles is. The pH in solution quickly raised from about 5-6 to 8-9 at the beginning of tests and then maintained at around 8-9 to the end of tests. The ORP in solutions descended to reductive state immediately at the beginning of tests and kept in the range between -730 and -770 mV to the end of tests indicating that the system maintained in a stable reductive state.","PeriodicalId":11324,"journal":{"name":"DEStech Transactions on Environment, Energy and Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91314716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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