In view of failure phenomena with nonlinear large deformation including extensive damage,whole section destruction in short time,high rate of repair,most destruction forms occurred in the tertiary roadway of soft rock...In view of failure phenomena with nonlinear large deformation including extensive damage,whole section destruction in short time,high rate of repair,most destruction forms occurred in the tertiary roadway of soft rocks engineering in Liuhai mine,according to the methods of geological survey,theoretical analysis,numerical calculation and in-situ test,the composite failure mechanism of molecular expansion,tectonic stress,gravity stress and engineering deviatoric stress,faults and random joint in this area is analyzed deeply,then an coupling support of double-layer-truss is proposed.The research results show that the first wave of deformation energy was released by bolt-mesh-cable fixed into the roof,floor and two sides of the roadway.While the second wave of deformation energy was released through the interface function between double-layer-truss and the surrounding rock.The double-layer-truss that characterized by high strength,good integrity can absorb high deformation energy of surrounding rocks,which led to the uniform distribution of the stress.Engineering practice shows this technology has been successfully applied to control the deformation failure of the tertiary extremely soft rock roadway.展开更多
The architectural patterns of sedimentary succession are diverse in different depositionalbasins. The sedimentary architecture and geological condition of such basins asepicontinental sea, intraplate limnic basins, et...The architectural patterns of sedimentary succession are diverse in different depositionalbasins. The sedimentary architecture and geological condition of such basins asepicontinental sea, intraplate limnic basins, etc., differ cIearly from those of continentalmargin basin. Extension, complement and perfection of sequence stratigraphic models are needed in the studies of various depositional basins based on the classical sequence model. This paper, for this reason,expounds the thought, principles of sequence division, methodology and technology of the study of sequence stratigraphy in epicontinental and limnic basins.展开更多
In recent years, studies show that coal formed during marine transigression process is also important in coal accumulation basin. Still, the characteristics of coal formation is more clearly demonstrated by the coal f...In recent years, studies show that coal formed during marine transigression process is also important in coal accumulation basin. Still, the characteristics of coal formation is more clearly demonstrated by the coal formation in TST in the sequence stratigraphic framework. Based on the study of the characteristics of coal formation in epicontinental coal accumulation basin, the viewpoint that coal was formed under marine transgression was put forward by the authors and the mechenism thereof was also analyized. Marine transgression resulted in the forming of swamp and then the peat swamp. And the transgression later on put the peat formed in advance in deep water environment to form coal in the end. The important stratigraphic horrizons, such as coal seams, marine facies layers, formed with marine transgression are of the property of isochronism.展开更多
Beach titanomagnetite(TTM)provides a cheap alternative source of Fe and Ti,but this ore is difficult to process to make suitable concentrates for the blast furnace.Recently studies showed that it is feasible to separa...Beach titanomagnetite(TTM)provides a cheap alternative source of Fe and Ti,but this ore is difficult to process to make suitable concentrates for the blast furnace.Recently studies showed that it is feasible to separate Fe and Ti by coal-based direct reduction.In this study,beach TTM was selected as the research object,the effects of reducing agents on reducing atmosphere in coal-based direct reduction of beach TTM were analyzed,and the role of volatiles was also studied.The results showed that when bitumite and coke were used as reducing agents of TTM,the CO produced from volatiles was involved in the reduction reaction,and the generated CO_(2) provided the raw material for the reaction of TTM.The reduction effect of bitumite was better than that of coke.The reason is that bitumite+TTM had a higher gas generation rate and produced a higher CO partial pressure,while coke+TTM had a lower gas generation rate and produced a lower CO partial pressure.When graphite was used as a reducing agent,there was a solid-solid reaction in the early stage in the reaction.With the continuous accumulation of CO_(2),the Boudouad reaction started and accelerated.Graphite+TTM also produced a higher CO partial pressure.展开更多
Aiming to address the following major engineering issues faced by the Pingdingshan No. 12 mine:(1) difficulty in implementing auxiliary lifting because of its depth(i.e., beyond 1000 m);(2) highly gassy main coal seam...Aiming to address the following major engineering issues faced by the Pingdingshan No. 12 mine:(1) difficulty in implementing auxiliary lifting because of its depth(i.e., beyond 1000 m);(2) highly gassy main coal seam with low permeability;(3) unstable overlying coal seam without suitable conditions for implementing conventional mining techniques for protective coal seam; and(4) predominant reliance on ‘‘under three" coal resources to ensure production output. This study proposes an integrated, closed-cycle mining-dressing-gas draining-backfilling-mining(MDGBM) technique. The proposed approach involves the mining of protective coal seam, underground dressing of coal and gangue(UDCG), pressure relief and gas drainage before extraction, and backfilling and mining of the protected coal seam. A system for draining gas and mining the protective seam in the rock stratum is designed and implemented based on the geological conditions. This system helps in realizing pressure relief and gas drainage from the protective seam before extraction. Accordingly, another system, which is connected to the existing production system, is established for the UDCG based on the dense medium-shallow trough process. The mixed mining workface is designed to accommodate both solid backfill and conventional fully mechanized coal mining, thereby facilitating coal mining, USCG, and backfilling. The results show that: The mixed mining workface length for the Ji15-31010 protected seam was 220 m with coal production capacity 1.2 million tons per year, while the backfill capacity of gangue was 0.5 million tons per year. The gas pressure decreased from 1.78 to 0.35 MPa, and the total amount of safely mined coal was 1.34 million tons. The process of simultaneously exploiting coal and draining gas was found to be safe, efficient, and green.This process also yielded significant economic benefits.展开更多
According to the classification standard of spontaneous combustion "three zone" in gob and the analysis of aerodynamics and energy equation of relax loose coal body, the paper used the method of computer simulation ...According to the classification standard of spontaneous combustion "three zone" in gob and the analysis of aerodynamics and energy equation of relax loose coal body, the paper used the method of computer simulation analysis to get the air distribution. The paper also determined the three zone area of H2103 fully mechanized caving face in Beizao Mine.展开更多
Estimation of S-wave velocity using logging data has mainly been performed for sandstone, mudstone and oil and gas strata, while its application to hydrate reservoirs has been largely overlooked. In this paper we pres...Estimation of S-wave velocity using logging data has mainly been performed for sandstone, mudstone and oil and gas strata, while its application to hydrate reservoirs has been largely overlooked. In this paper we present petxophysical methods to estimate the S-wave velocity of hydrate reservoirs with the P-wave velocity and the density as constraints. The three models used in this paper are an equivalent model (MBGL), a three-phase model (TPBE), and a thermo-elasticity model (TEM). The MBGL model can effectively describe the internal relationship among the components of the rock, and the estimated P-wave velocities are in good agreement with the measured data (2.8% error). However, in the TPBE model, the solid, liquid and gas phases axe considered to be independent of each other, and the estimation results are relatively low (46.6% error). The TEM model is based on the sensitivity of the gas hydrate to temperature and pressure, and the accuracy of the estimation results is also high (3.6% error). Before the estimation, the occurrence patterns of hydrates in the Shenhu area were examined, and occurrence state one (the hydrate is in solid form in the reservoir) was selected for analysis. By using the known P-wave velocity and density as constraints, a reasonable S-wave velocity value (ranging from 400 to 1100 m s 1 and for a hydrate layer of 1100 m s 1) can be obtained through multiple iterations. These methods and results provide new data and technical support for further research on hydrates and other geological features in the Shenhu area.展开更多
The Paleogene coal accumulation basins of China are part of the global Tertiary coal-accumulated zone of the Pacific Rim located in the eastern coastal provinces and areas. Although the coal-bearing basins of the Chin...The Paleogene coal accumulation basins of China are part of the global Tertiary coal-accumulated zone of the Pacific Rim located in the eastern coastal provinces and areas. Although the coal-bearing basins of the China Sea area are faults and depressed basins, they come up in groups. The overall structures are suitable for the development of coal-bearing deposition. The continuity of basin groups are good, and the coal-bearing depositions are thick. For example, the coal-bearing deposi- tion is more than a kilometer thick at the Qiongdongnan Basin and Xihu Sag in the East China Sea, which the continental Pa- leogene coal basins cannot reach. Research shows that the coal accumulation basins in the sea area consist of many sags. There are two types of coal accumulation sags: half-graben sag and graben sag. In terms of water depth, coal accumulation sags can also be classified as deep-water half-graben sag and shallow-water half-graben sag; the graben sag is the deep-water sag. There are two distinct coal-accumulated zones in the basin: gentle slope and steep slope, with the gentle slope being the dominant one. The marshes of the supratidal zone and intertidal zone in a tidal flat system is favorable for the coal accumulation process widely taking place. There are two types of peat accumulation: autochthonous accumulation and allochthonous accumulation. Because of tectonic activities in the basins, allochthonous accumulations may be the more important form of coal-forming ac- tivities in the sea area. The very thick coal-bearing deposition in the sea area provides a rich material base for the assemblage of coal-related gas. Also, as a result of the deep burial depth, the degree of coal metamorphism is relatively high, so the coal-bearing strata become good hydrocarbon source rocks.展开更多
This paper analyzes the status quo and progress of overseas oil and gas business cooperation built by Chinese oil enterprises in 2017. With the slow recovery of the oil and gas industries as a whole, the overseas oil ...This paper analyzes the status quo and progress of overseas oil and gas business cooperation built by Chinese oil enterprises in 2017. With the slow recovery of the oil and gas industries as a whole, the overseas oil and gas business of Chinese oil enterprises has continued to grow in size, and all-round cooperation progress was made along the Belt and Road. Breakthroughs were made in oil and gas cooperation between China and the United States. In the meantime, new features have emerged in the overseas cooperation of Chinese enterprises, and a pattern of diversified investors has basically taken shape.展开更多
In order to study the effects of soil compaction, and soil physical and chemicalcharacteristics after land reclamation, selected lands that were reclaimed after 1, 2, 3, 4,and 5 a, respectively, in the Majiata Mine of...In order to study the effects of soil compaction, and soil physical and chemicalcharacteristics after land reclamation, selected lands that were reclaimed after 1, 2, 3, 4,and 5 a, respectively, in the Majiata Mine of the Shendong Open Pit; tested the effects ofsoil compaction; and collected soil samples from 5 different depths, which are 0-7.62,7.62-15.24, 15.24-22.86, 22.86-30.48, and 30.48-38.10 cm, respectively. The resultsshow that: Land reclamation leads to soil compaction. The lowest effect of soil compaction is in the top layer and the highest one at the depth of 20-30 cm; The bulk density of reclaimed soil is higher than that of undisturbed soil; this declines with the reclamation and nearly reaches the level of undisturbed soil after 5-year reclamation;The content of reclaimed soil nutrients is lower than that of undisturbed soil. The lowest one is inthe soil dumping site, which reaches the level of undisturbed soil after 5-year reclamation;The pH value of reclaimed soil is lower than that of undisturbed soil. The highest one isin the soil dumping site; this declines with the reclamation.展开更多
The mechanical property of mudstone/shale in coal measures is a key factor of engineering mechanics that influences the development of shale gas. A rock mechanics test was performed in order to analyze the complete st...The mechanical property of mudstone/shale in coal measures is a key factor of engineering mechanics that influences the development of shale gas. A rock mechanics test was performed in order to analyze the complete stress-strain mechanic characteristics and influence factors of mudstone/shale in paralic coal measures, from the Carboniferous-Permian periods in a coal field of Northern China. The relationship between the mechanical properties of mudstone/shale in coal measures, and its chemical component, water content are established, and their models are constructed. Research results show that mud- stone/shale has low mechanical strength, low elastic modulus and a high Poisson's ratio. The complete stress-strain curve has apparent elastoplastic deformation characteristics, and after reaching peak strength, it exhibits obvious strain softening characteristics. The uniaxial compressive strength of mudstone/shale and its elastic modulus increases exponentially with the increase of SiO2 content, and as the ignition loss increases, the uniaxial compressive strength and elastic modulus of mudstone/shale will decrease according to the law of power function. The compressive strength of mudstone/shale and its elastic modulus will decrease with the increase of water content in mudstone/shale.展开更多
In this paper, the environment characteristics, micro-environment division and evolution of the mangrove tidal flats, peats and their genetic markers are discussed. It proves that the mangrove tidal flat is a kind of ...In this paper, the environment characteristics, micro-environment division and evolution of the mangrove tidal flats, peats and their genetic markers are discussed. It proves that the mangrove tidal flat is a kind of tidal flats and the peat flats are developed in a specific evolution stage of mangrove tidal flats; the mangrove peats are the products of a specific evolution stage of the mangrove tidal flats.展开更多
Over 70% brown coal reserves have been exploited in the North Bohemian Basin today. Openeast mining of brown coal naturally led to large landscape damages, Therefore reclamation work has acquired a great significance....Over 70% brown coal reserves have been exploited in the North Bohemian Basin today. Openeast mining of brown coal naturally led to large landscape damages, Therefore reclamation work has acquired a great significance. The research methodology of the areas of interests and the reclamation works themselves described in this article arises from North Bohemian Mines locality reclamation philosophy. Apart from the earlier published methodology of fertilizable soils application used today in operation, experiments with filling areas left for natural succession and pilot have been launched lately. The results are stated in the paper. application of power plant stabilizer and ash in phyto-toxic areas展开更多
Using seawater in concrete can be considered as one of the sustainable approaches in construction industry not only to save the freshwater resource but also to promote the use of abandoned seawater resource, especiall...Using seawater in concrete can be considered as one of the sustainable approaches in construction industry not only to save the freshwater resource but also to promote the use of abandoned seawater resource, especially in the construction at the uninhabited area close to the sea where the procurement of fresh water is difficult. In this study, durability against chloride attack of seawater mixed concrete with different replacement ratio of BFS (blast furnace slag) and FA (fly ash) is discussed and the life time until the occurrence of corrosion crack is evaluated. The results show that: (1) Chloride penetration rate of seawater mixed specimens with BFS and FA is lower than that of freshwater mixed OPC (ordinary Portland cement) specimens; (2) Oxygen permeability of seawater mixed specimens with BFS and FA is almost the same or lower than that of freshwater mixed OPC specimens; (3) Total life time (corrosion incubation period and propagation period) of seawater mixed specimens with BFS and FA is almost the same or only slightly shorter than that of freshwater mixed OPC specimens. From the results, it was confirmed that the usage of seawater in concrete mixing is feasible in concrete with the appropriate BFS and FA replacement ratio.展开更多
In order to study the soil enzyme content at the mine reclamation area and choose a tree species with superior restoration capabilities, this paper takes Huainan Datong Mine as the study area, and five different enzym...In order to study the soil enzyme content at the mine reclamation area and choose a tree species with superior restoration capabilities, this paper takes Huainan Datong Mine as the study area, and five different enzymes under nine tree species as the study subject. The different enzyme activity indexes were measured, and the correlation analysis and the principal component analysis (PCA) method were applied to evaluate and screen the tree species with advanced restoration. The results demonstrate that there are some correlations among the different soil enzymes, including some very significant positive correlations among urease, phosphatase, invertase and protease. The best species in terms of repair is privet, and the worst is Haltong. This study provides a scientific basis for the selection of restoration-capable tree species in the reclamation area of the coal mine.展开更多
基金supported by program for the National Natural Science Foundation of China (No.51304210)the Specialized Research Foundation for the Doctoral Program of Higher Education by the Ministry of Education (No.20120023120014)
文摘In view of failure phenomena with nonlinear large deformation including extensive damage,whole section destruction in short time,high rate of repair,most destruction forms occurred in the tertiary roadway of soft rocks engineering in Liuhai mine,according to the methods of geological survey,theoretical analysis,numerical calculation and in-situ test,the composite failure mechanism of molecular expansion,tectonic stress,gravity stress and engineering deviatoric stress,faults and random joint in this area is analyzed deeply,then an coupling support of double-layer-truss is proposed.The research results show that the first wave of deformation energy was released by bolt-mesh-cable fixed into the roof,floor and two sides of the roadway.While the second wave of deformation energy was released through the interface function between double-layer-truss and the surrounding rock.The double-layer-truss that characterized by high strength,good integrity can absorb high deformation energy of surrounding rocks,which led to the uniform distribution of the stress.Engineering practice shows this technology has been successfully applied to control the deformation failure of the tertiary extremely soft rock roadway.
文摘The architectural patterns of sedimentary succession are diverse in different depositionalbasins. The sedimentary architecture and geological condition of such basins asepicontinental sea, intraplate limnic basins, etc., differ cIearly from those of continentalmargin basin. Extension, complement and perfection of sequence stratigraphic models are needed in the studies of various depositional basins based on the classical sequence model. This paper, for this reason,expounds the thought, principles of sequence division, methodology and technology of the study of sequence stratigraphy in epicontinental and limnic basins.
基金Supported by the 973 Projects under Grant(2002CB211706 and 2003 CB214608)
文摘In recent years, studies show that coal formed during marine transigression process is also important in coal accumulation basin. Still, the characteristics of coal formation is more clearly demonstrated by the coal formation in TST in the sequence stratigraphic framework. Based on the study of the characteristics of coal formation in epicontinental coal accumulation basin, the viewpoint that coal was formed under marine transgression was put forward by the authors and the mechenism thereof was also analyized. Marine transgression resulted in the forming of swamp and then the peat swamp. And the transgression later on put the peat formed in advance in deep water environment to form coal in the end. The important stratigraphic horrizons, such as coal seams, marine facies layers, formed with marine transgression are of the property of isochronism.
基金Project(52104257)supported by the National Natural Science Foundation of China。
文摘Beach titanomagnetite(TTM)provides a cheap alternative source of Fe and Ti,but this ore is difficult to process to make suitable concentrates for the blast furnace.Recently studies showed that it is feasible to separate Fe and Ti by coal-based direct reduction.In this study,beach TTM was selected as the research object,the effects of reducing agents on reducing atmosphere in coal-based direct reduction of beach TTM were analyzed,and the role of volatiles was also studied.The results showed that when bitumite and coke were used as reducing agents of TTM,the CO produced from volatiles was involved in the reduction reaction,and the generated CO_(2) provided the raw material for the reaction of TTM.The reduction effect of bitumite was better than that of coke.The reason is that bitumite+TTM had a higher gas generation rate and produced a higher CO partial pressure,while coke+TTM had a lower gas generation rate and produced a lower CO partial pressure.When graphite was used as a reducing agent,there was a solid-solid reaction in the early stage in the reaction.With the continuous accumulation of CO_(2),the Boudouad reaction started and accelerated.Graphite+TTM also produced a higher CO partial pressure.
基金supported by the Qing Lan Project Foundation of Jiangsu Province in 2014,Foundation for Distinguished professor of Jiangsu Province in 2015,Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.51421003)Project funded by China Postdoctoral Science Foundation(2016M601915)National Key Basic Research Program of China(No.2013CB227905)
文摘Aiming to address the following major engineering issues faced by the Pingdingshan No. 12 mine:(1) difficulty in implementing auxiliary lifting because of its depth(i.e., beyond 1000 m);(2) highly gassy main coal seam with low permeability;(3) unstable overlying coal seam without suitable conditions for implementing conventional mining techniques for protective coal seam; and(4) predominant reliance on ‘‘under three" coal resources to ensure production output. This study proposes an integrated, closed-cycle mining-dressing-gas draining-backfilling-mining(MDGBM) technique. The proposed approach involves the mining of protective coal seam, underground dressing of coal and gangue(UDCG), pressure relief and gas drainage before extraction, and backfilling and mining of the protected coal seam. A system for draining gas and mining the protective seam in the rock stratum is designed and implemented based on the geological conditions. This system helps in realizing pressure relief and gas drainage from the protective seam before extraction. Accordingly, another system, which is connected to the existing production system, is established for the UDCG based on the dense medium-shallow trough process. The mixed mining workface is designed to accommodate both solid backfill and conventional fully mechanized coal mining, thereby facilitating coal mining, USCG, and backfilling. The results show that: The mixed mining workface length for the Ji15-31010 protected seam was 220 m with coal production capacity 1.2 million tons per year, while the backfill capacity of gangue was 0.5 million tons per year. The gas pressure decreased from 1.78 to 0.35 MPa, and the total amount of safely mined coal was 1.34 million tons. The process of simultaneously exploiting coal and draining gas was found to be safe, efficient, and green.This process also yielded significant economic benefits.
基金Supported by the National Natural Science Foundation of China(50534080)
文摘According to the classification standard of spontaneous combustion "three zone" in gob and the analysis of aerodynamics and energy equation of relax loose coal body, the paper used the method of computer simulation analysis to get the air distribution. The paper also determined the three zone area of H2103 fully mechanized caving face in Beizao Mine.
基金supported by the National Natural Science Foundation of China(Nos.41304096 and 41176077)the National Science and Technology Major Project of China(No.2016ZX05024-001-002)+2 种基金the National High-tech R&D Program of China(863 ProgramNo.2013AA0925 01)the Fundamental Research Funds for the Central Universities(No.201762019)
文摘Estimation of S-wave velocity using logging data has mainly been performed for sandstone, mudstone and oil and gas strata, while its application to hydrate reservoirs has been largely overlooked. In this paper we present petxophysical methods to estimate the S-wave velocity of hydrate reservoirs with the P-wave velocity and the density as constraints. The three models used in this paper are an equivalent model (MBGL), a three-phase model (TPBE), and a thermo-elasticity model (TEM). The MBGL model can effectively describe the internal relationship among the components of the rock, and the estimated P-wave velocities are in good agreement with the measured data (2.8% error). However, in the TPBE model, the solid, liquid and gas phases axe considered to be independent of each other, and the estimation results are relatively low (46.6% error). The TEM model is based on the sensitivity of the gas hydrate to temperature and pressure, and the accuracy of the estimation results is also high (3.6% error). Before the estimation, the occurrence patterns of hydrates in the Shenhu area were examined, and occurrence state one (the hydrate is in solid form in the reservoir) was selected for analysis. By using the known P-wave velocity and density as constraints, a reasonable S-wave velocity value (ranging from 400 to 1100 m s 1 and for a hydrate layer of 1100 m s 1) can be obtained through multiple iterations. These methods and results provide new data and technical support for further research on hydrates and other geological features in the Shenhu area.
基金Supported by the Major Research Project of the National Natural Science Foundation (40872100)
文摘The Paleogene coal accumulation basins of China are part of the global Tertiary coal-accumulated zone of the Pacific Rim located in the eastern coastal provinces and areas. Although the coal-bearing basins of the China Sea area are faults and depressed basins, they come up in groups. The overall structures are suitable for the development of coal-bearing deposition. The continuity of basin groups are good, and the coal-bearing depositions are thick. For example, the coal-bearing deposi- tion is more than a kilometer thick at the Qiongdongnan Basin and Xihu Sag in the East China Sea, which the continental Pa- leogene coal basins cannot reach. Research shows that the coal accumulation basins in the sea area consist of many sags. There are two types of coal accumulation sags: half-graben sag and graben sag. In terms of water depth, coal accumulation sags can also be classified as deep-water half-graben sag and shallow-water half-graben sag; the graben sag is the deep-water sag. There are two distinct coal-accumulated zones in the basin: gentle slope and steep slope, with the gentle slope being the dominant one. The marshes of the supratidal zone and intertidal zone in a tidal flat system is favorable for the coal accumulation process widely taking place. There are two types of peat accumulation: autochthonous accumulation and allochthonous accumulation. Because of tectonic activities in the basins, allochthonous accumulations may be the more important form of coal-forming ac- tivities in the sea area. The very thick coal-bearing deposition in the sea area provides a rich material base for the assemblage of coal-related gas. Also, as a result of the deep burial depth, the degree of coal metamorphism is relatively high, so the coal-bearing strata become good hydrocarbon source rocks.
文摘This paper analyzes the status quo and progress of overseas oil and gas business cooperation built by Chinese oil enterprises in 2017. With the slow recovery of the oil and gas industries as a whole, the overseas oil and gas business of Chinese oil enterprises has continued to grow in size, and all-round cooperation progress was made along the Belt and Road. Breakthroughs were made in oil and gas cooperation between China and the United States. In the meantime, new features have emerged in the overseas cooperation of Chinese enterprises, and a pattern of diversified investors has basically taken shape.
基金Supported by the China Postdoctoral Science Foundation of China (20060400532, 2006DS08018)
文摘In order to study the effects of soil compaction, and soil physical and chemicalcharacteristics after land reclamation, selected lands that were reclaimed after 1, 2, 3, 4,and 5 a, respectively, in the Majiata Mine of the Shendong Open Pit; tested the effects ofsoil compaction; and collected soil samples from 5 different depths, which are 0-7.62,7.62-15.24, 15.24-22.86, 22.86-30.48, and 30.48-38.10 cm, respectively. The resultsshow that: Land reclamation leads to soil compaction. The lowest effect of soil compaction is in the top layer and the highest one at the depth of 20-30 cm; The bulk density of reclaimed soil is higher than that of undisturbed soil; this declines with the reclamation and nearly reaches the level of undisturbed soil after 5-year reclamation;The content of reclaimed soil nutrients is lower than that of undisturbed soil. The lowest one is inthe soil dumping site, which reaches the level of undisturbed soil after 5-year reclamation;The pH value of reclaimed soil is lower than that of undisturbed soil. The highest one isin the soil dumping site; this declines with the reclamation.
基金Supported by the National Basic Research Program of China (973 Program) (2012CB214705) the National Natural Science Foundation of China 41172145, 41030422) the Shanxi Provincial Basic Research Program-Coal Bed Methane Joint Research Foundation (2012012014)
文摘The mechanical property of mudstone/shale in coal measures is a key factor of engineering mechanics that influences the development of shale gas. A rock mechanics test was performed in order to analyze the complete stress-strain mechanic characteristics and influence factors of mudstone/shale in paralic coal measures, from the Carboniferous-Permian periods in a coal field of Northern China. The relationship between the mechanical properties of mudstone/shale in coal measures, and its chemical component, water content are established, and their models are constructed. Research results show that mud- stone/shale has low mechanical strength, low elastic modulus and a high Poisson's ratio. The complete stress-strain curve has apparent elastoplastic deformation characteristics, and after reaching peak strength, it exhibits obvious strain softening characteristics. The uniaxial compressive strength of mudstone/shale and its elastic modulus increases exponentially with the increase of SiO2 content, and as the ignition loss increases, the uniaxial compressive strength and elastic modulus of mudstone/shale will decrease according to the law of power function. The compressive strength of mudstone/shale and its elastic modulus will decrease with the increase of water content in mudstone/shale.
文摘In this paper, the environment characteristics, micro-environment division and evolution of the mangrove tidal flats, peats and their genetic markers are discussed. It proves that the mangrove tidal flat is a kind of tidal flats and the peat flats are developed in a specific evolution stage of mangrove tidal flats; the mangrove peats are the products of a specific evolution stage of the mangrove tidal flats.
文摘Over 70% brown coal reserves have been exploited in the North Bohemian Basin today. Openeast mining of brown coal naturally led to large landscape damages, Therefore reclamation work has acquired a great significance. The research methodology of the areas of interests and the reclamation works themselves described in this article arises from North Bohemian Mines locality reclamation philosophy. Apart from the earlier published methodology of fertilizable soils application used today in operation, experiments with filling areas left for natural succession and pilot have been launched lately. The results are stated in the paper. application of power plant stabilizer and ash in phyto-toxic areas
文摘Using seawater in concrete can be considered as one of the sustainable approaches in construction industry not only to save the freshwater resource but also to promote the use of abandoned seawater resource, especially in the construction at the uninhabited area close to the sea where the procurement of fresh water is difficult. In this study, durability against chloride attack of seawater mixed concrete with different replacement ratio of BFS (blast furnace slag) and FA (fly ash) is discussed and the life time until the occurrence of corrosion crack is evaluated. The results show that: (1) Chloride penetration rate of seawater mixed specimens with BFS and FA is lower than that of freshwater mixed OPC (ordinary Portland cement) specimens; (2) Oxygen permeability of seawater mixed specimens with BFS and FA is almost the same or lower than that of freshwater mixed OPC specimens; (3) Total life time (corrosion incubation period and propagation period) of seawater mixed specimens with BFS and FA is almost the same or only slightly shorter than that of freshwater mixed OPC specimens. From the results, it was confirmed that the usage of seawater in concrete mixing is feasible in concrete with the appropriate BFS and FA replacement ratio.
文摘In order to study the soil enzyme content at the mine reclamation area and choose a tree species with superior restoration capabilities, this paper takes Huainan Datong Mine as the study area, and five different enzymes under nine tree species as the study subject. The different enzyme activity indexes were measured, and the correlation analysis and the principal component analysis (PCA) method were applied to evaluate and screen the tree species with advanced restoration. The results demonstrate that there are some correlations among the different soil enzymes, including some very significant positive correlations among urease, phosphatase, invertase and protease. The best species in terms of repair is privet, and the worst is Haltong. This study provides a scientific basis for the selection of restoration-capable tree species in the reclamation area of the coal mine.