OBE theory focuses on students’learning outcomes and application ability,which is consistent with the requirements of the new curriculum standard.The paper attempts to apply OBE theory to innovate the construction of...OBE theory focuses on students’learning outcomes and application ability,which is consistent with the requirements of the new curriculum standard.The paper attempts to apply OBE theory to innovate the construction of English classroom teaching mode in senior high schools from aspects of teaching aims,teaching activities,teaching assessments and application activities.Results show that the application of OBE in high schools is beneficial to the development of English teaching and students'learning.展开更多
The earth-rockfill dam is one of the primary dam types in the selection of high dams to be constructed in Western China, since it is characterized by favorable adaptability of the dam foundation; full utilization of l...The earth-rockfill dam is one of the primary dam types in the selection of high dams to be constructed in Western China, since it is characterized by favorable adaptability of the dam foundation; full utilization of local earth, rock, and building-excavated materials; low construction cost; and low cement consumption. Many major technical issues regarding earth-rockfill dams with a height of over 250 m were studied and solved successfully in the construction of the 261.5 m Nuozhadu earth core rockfill dam. This paper describes research achievements and basic conclusions; systematically summarizes the accumulated experiences from the construction of the Nuozhadu Dam and other high earth-rockfill dams; and discusses major technical issues, such as deformation control, seepage control, dam slope stability, safety and control of flood discharging, safety and quality control of dam construction, safety assessments, early warning, and other key technical difficulties. This study also provides a reference and technological support for the future construction of 300 m high earth-rockfill dams.展开更多
A method of combining dynamic simulation with real-time control was proposed to fit the randomness and uncertainty in the high arch dam construction process. The mathematical logic model of high arch dam construction ...A method of combining dynamic simulation with real-time control was proposed to fit the randomness and uncertainty in the high arch dam construction process. The mathematical logic model of high arch dam construction process was established. By combining dynamic construction simulation with schedule analysis, the process of construction schedule forecasting and analysis based on dynamic simulation was studied. The process of real-time schedule control was constructed and some measures for dynamic adjustment and control of construction schedule were provided. A system developed with the method is utilized in a being constructed hydroelectric project located at the Yellow River in northwest China, which can make the pouring plan of the dam in the next stage (a month, quarter or year) to guide the practical construction. The application result shows that the system provides an effective technical support for the construction and management of the dam.展开更多
Creep tests under at a certain temperature and different stress levels were performed on two carbon constructional quality steels at a certain stress level and different temperatures,and their creep curves at high tem...Creep tests under at a certain temperature and different stress levels were performed on two carbon constructional quality steels at a certain stress level and different temperatures,and their creep curves at high temperature were obtained based on analyzing the testing data.Taking 45 steel at a certain temperature and stress as the example,the integral creep constitutive equation and the differential stress-strain constitutive relationship were established based on the relevant rheological model,and the integral core function was also obtained.Simultaneously,the viscous coefficients denoting the viscous behavior in visco-plastic constitutive equation were determined by taking use of the creep testing data.Then the viscous coefficients of three carbon steels(20 steel,35 steel and 45 steel) were compared and analyzed.The results show that the viscosity is different due to different materials at the same temperature and stress.展开更多
A self-developed elasto-plastic finite element program was used to analyze the construction sequence of high rock slope's stabilization in a coal-coking plant, and the result was compared with that employing the u...A self-developed elasto-plastic finite element program was used to analyze the construction sequence of high rock slope's stabilization in a coal-coking plant, and the result was compared with that employing the ultimate equilibrium method. Based on the results of finite element analysis, the stress contour graphs and displacement vector graphs at different construction steps were obtained, and the behavior of the slope during stabilization construction process was analyzed quantitatively. Based on the analysis of safety factors of three different schemes of stabilization and two different construction schemes, the assessment of stability and bracing design of the construction process were performed. The results show that the original reinforcement design is improper; the stability of the rock slope is controlled by a developed structural plane, the stability factor after excavation is less than 1, and the free surface should be braced in time; for stability, the construction sequence should adopt that bracing follows excavation step by step up to down; the local slide occurred during the construction process agrees with the dangerous slide determined by the numerical analysis, which proves the validity and rationality of the adopted method.展开更多
On the basis of actual situations of Guangdong Province, using Factor Analysis Approach and Quantitative Analysis Method, we built index system by four factors, namely, extent of farmland connectivity, local financial...On the basis of actual situations of Guangdong Province, using Factor Analysis Approach and Quantitative Analysis Method, we built index system by four factors, namely, extent of farmland connectivity, local financial support, grain production capacity and farmland consolidation potential. Finally, we obtained that the areas with total scores of evaluation higher than 50 points are key construction areas of high-standard capital farmland in Guangdong Province. In total, there are 40 key construction areas, including 16 in plain areas of the Pearl River Delta, 9 in coastal regions of east of Guangdong, 10 in coastal regions of west of Guangdong, and 5 in northwest mountainous regions of Guangdong. Besides, we put forward construction direction of these 4 capital farmland areas.展开更多
In the process of tunnel construction,if large-deformation occurs in high geostress soft rock,it will likely cause geological disasters.This situation will not only seriously affect the smooth progress of tunnel const...In the process of tunnel construction,if large-deformation occurs in high geostress soft rock,it will likely cause geological disasters.This situation will not only seriously affect the smooth progress of tunnel construction,but also cause serious safety threat to the construction personnel.Therefore,with the continuous growth in the number and scale of tunnel construction in recent years,the construction technology for high geostress soft rock with large-deformation has begun to receive more and more attention from the society.Based on this,this paper takes an actual project as an example to analyze the specific application of the technology in order to improve the construction effect and avoid the damage caused by the large-deformation of the high geostress soft rock.展开更多
Massive amounts of limestone waste are produced by the stone processing industry worldwide. Generally, it is believed that 60% to 70% of the stone is wasted in processing in the form of fragments, powder and slurry ou...Massive amounts of limestone waste are produced by the stone processing industry worldwide. Generally, it is believed that 60% to 70% of the stone is wasted in processing in the form of fragments, powder and slurry out of which around 30% is in the form of fine powder [1]. This waste has no beneficial usage and poses environmental hazards. Use of this waste product in the construction industry can largely reduce the amount of waste to be disposed off by the local municipalities in addition to reducing large burden on the environment. Some basic research on use of limestone dust as cement/ concrete filler?has?been carried out in the recent past but high strength/ high performance concretes have not been investigated yet [2] [3]. The concrete industry is among the largest consumer of raw materials worldwide and has been investigated for use of various types of waste materials like crushed brick, rice husk and straw ash as either aggregates for concrete or as partial cement substitutes. Use of limestone dust as filler material in concrete can consume a huge amount of this waste material which has to be disposed off otherwise, creating large burden on the environment. This experimental study aimed at evaluating the properties of high performance concretes made from Portland cement, natural aggregates and sand. Limestone dust was added by replacing sand in the percentages of 10% and 20%. Wide ranging investigations covering most aspects of mechanical behavior and permeability were carried out for various mixes for compressive strengths of 60?N/mm2, 80?N/mm2 and 100?N/mm2. Compressive strengths of concrete specimen with partial replacement of sand with 10% and 20% limestone dust as filler material for 60?N/mm2, 80N/mm2 and 100?N/mm2 were observed to be higher by about 4% to 12% than the control specimen. Flexural strengths were also observed to be higher by 12%?-?13%. Higher elastic moduli and reduced permeability were observed along with better sulphate and acid resistance. Better strengths and improved durability of such high-performance concretes make it a more acceptable material for major construction projects.展开更多
At the beginning of 21st century, with the rapid and steady development of China economy, a lot of large scale hydropower projects with large dams from 200 m to 300 m high are being or to be built. China dam construct...At the beginning of 21st century, with the rapid and steady development of China economy, a lot of large scale hydropower projects with large dams from 200 m to 300 m high are being or to be built. China dam constructions are reaching the level of 300 m high arch dam, 250 high CFRD (concrete face rockfill dam) and 200 m high RCC (roller compacted concrete) gravity dam. Due to the safety and the economy, the type selection for high dams has become the key issue during the argumentation for the hydropower projects, and further efforts are still needed in this aspect for high dams. After reviewing the high dam constructions in China and abroad, authors proposed some advices for the selection of dam types, and hope that it can provide some helpful information for the researches and the design of high dams.展开更多
The high and large span cast-in-place reinforced concrete cantilever structure of the office building of some court, which is located I-steel at the cantilever and used steel pipe scaffold as the support, has guarante...The high and large span cast-in-place reinforced concrete cantilever structure of the office building of some court, which is located I-steel at the cantilever and used steel pipe scaffold as the support, has guaranteed the frame body and structure security by the frame body calculating, on-site test and reasonable construction order.展开更多
To introduce foreign capital for the municipal highway construction is a great measure to meet the development of the socialist market economy and to reform the investment system for the municipal highway construction...To introduce foreign capital for the municipal highway construction is a great measure to meet the development of the socialist market economy and to reform the investment system for the municipal highway construction. The aim of the reform lies in taking the construction and management of the municipal highway facilities as an industry to operate, widening the investment channel of the municipal highway construction and gradually forming a benign cycle of investment-construc-展开更多
In this article, the features of design and construction of Qinhuangdao Shenyang passenger special line in railroad foundation, tracks, and bridges are described as an emphasis, the reasons for success are analyzed, a...In this article, the features of design and construction of Qinhuangdao Shenyang passenger special line in railroad foundation, tracks, and bridges are described as an emphasis, the reasons for success are analyzed, and the recommendations to tackle the exiting issues are presented as the reference in high speed railway construction.展开更多
High-speed railways have the merits of high speed, high transport capacity, low consumption of energy, less pollution, less occupation of land, and greater safety. The development of high-speed railways is suitable fo...High-speed railways have the merits of high speed, high transport capacity, low consumption of energy, less pollution, less occupation of land, and greater safety. The development of high-speed railways is suitable for the national conditions in China.The authors suggest that, with the Hu-Ning (Shanghai-Nanjing) section of the Jing-Hu (Beijing-Shanghai) Railway as the starting point, a high-speed dedicated passenger railway line be built to realize the separate transportation of passengers and goods, thus easing the strain on transport in East China, accumulating experience for the future development of high-speed railways, and bringing along the development of high and new technology industries.展开更多
Large-scale transportation infrastructure construction in ecologically vulnerable areas such as the karst region of Southwest China requires estimation method for better project design.This research was carried out on...Large-scale transportation infrastructure construction in ecologically vulnerable areas such as the karst region of Southwest China requires estimation method for better project design.This research was carried out on a four-lane highway(the Guilin-Guiyang highway,G76)and a two-lane highspeed railway(the Guilin-Guiyang high-speed railway,GGHSR)in karst areas in Guizhou and Guangxi provinces.The highway and high-speed railway were constructed in the 2010 s and covered by Landsat images whose multispectral information could be used for research purposes.In this study,the severity of the impact and the CO2 emissions from the G76 and GGHSR construction were evaluated.Landsat images and field meteorological measurements were applied to calculate the surface functional parameters(surface temperature and surface wetness)and heat fluxes(latent,sensible and ground heat flux)before and during the highway and high-speed railway construction;the amount of CO2 emissions during the G76 and GGHSR construction were determined by using budget sheets,which record the detail consumptions of materials and energy.The results showed that the decrease of water evaporation from the highway and high-speed railway construction can reach up to 26.4 m3 and 20.1 m3 per kilometer,which corresponds to an average decrease in the vegetation cooling effect of 18.0 MWh per day per highway kilometer and 13.7 MWh per day per high-speed railway kilometer,respectively.At the meantime,the average CO2 emission densities from the G76 and GGHSR construction can reach up to 24813.7 and 36921.1 t/km,respectively.This study implied that extensive line constructions have a significant impact on the local climate and the energy balance,and it is evident that selecting and planting appropriate plant species can compensate for the adverse effects of line constructions in karst mountain regions.展开更多
Based on the data of the construction industry in Henan Province, China, from 2005 to 2020, the high-quality development level of the construction industry in Henan Province is measured. Firstly, this paper constructs...Based on the data of the construction industry in Henan Province, China, from 2005 to 2020, the high-quality development level of the construction industry in Henan Province is measured. Firstly, this paper constructs the indicator system based on the high-quality development theory and the characteristic of the construction industry from seven dimensions: industrial scale, industrial efficiency, industrial benefits, industrial innovation, industrial risk, industrial potential, and the green development of the construction industry. Secondly, using the global principal component analysis (PCA) method to measure the high-quality development level. Thirdly, cluster analysis is applied to measure the relative changes of various dimensions in different stages. The results show that overall the high-quality development level of the construction industry in Henan province is increasing, but different indicators perform differently in various stages, and the changes in real estate policies have a significant impact on this. Finally, based on these findings, we think it is better to reduce real estate dependence, promote the application of new materials and technologies and maintain the stability of real estate policies.展开更多
Presents the reverse construction of Harbin Aerospace Building basement,which features improved working conditions,short time of construction,and reduced construction cost.
In order to provide the model point accuracy of ±2 mm,an extra high accuracy industrial control net with four surveying piers with accuracy ±0.1 mm was set up around the model.Tens of orientation marks have ...In order to provide the model point accuracy of ±2 mm,an extra high accuracy industrial control net with four surveying piers with accuracy ±0.1 mm was set up around the model.Tens of orientation marks have been placed on the different parts and measured with accuracy ±0.2 mm from the above_mentioned piers.The main four stereopairs taken with the P31 camera around the model are simultaneously processed on the BC2 analytical plotter.The accuracy of absolute orientation is better than ±0.9 mm.Finally,about 300 sections construction drawings have been directly offered,and the close_range photogrammetric data has been used for the design and construction of the statue.展开更多
Factors such as errors during the fabrication or construction of structural components and errors of calculation as- sumption or calculation methods, are very likely to cause serious deviation of many strings’ actual...Factors such as errors during the fabrication or construction of structural components and errors of calculation as- sumption or calculation methods, are very likely to cause serious deviation of many strings’ actual prestressing forces from the designed values during tension structure construction or service period, and further to threaten the safety and reliability of the structure. Aiming at relatively large errors of the prestressing force of strings in a tension structure construction or service period, this paper proposes a new finite element method (FEM), the "tensile force correction calculation method". Based on the measured prestressing forces of the strings, this new method applies the structure from the zero prestressing force status approach to the measured prestressing force status for the first phase, and from the measured prestressing force status approach to the designed prestressing force status for the second phase. The construction tensile force correction value for each string can be obtained by multi-iteration with FEM. Using the results of calculation, the strings’ tensile force correction by group and in batch will be methodic, simple and accurate. This new calculation method can be applied to the prestressed correction construction simulation analysis for tension structures.展开更多
In the tide of China’s reform, opening and modern construction, Shanghai has achieved great success. On his inspection, Deng Xiaoping, the architect of China’s economic reform said," Shanghai has progressed in ...In the tide of China’s reform, opening and modern construction, Shanghai has achieved great success. On his inspection, Deng Xiaoping, the architect of China’s economic reform said," Shanghai has progressed in a year and made great progress in three years." In the 1920s and 1930s, Shanghai was a world economic, financial and trade centre and famed as "the Paris of the Orient."展开更多
China needs to develop a strong national power grid which takes ultra-high-voltage (UHV) transmission systems as its core. The grid is expected to adopt 1000-kV-class AC and ± 800-kV DC transmission systems. In v...China needs to develop a strong national power grid which takes ultra-high-voltage (UHV) transmission systems as its core. The grid is expected to adopt 1000-kV-class AC and ± 800-kV DC transmission systems. In view of significant achievements in technological research and considerable progress in UHV manufacturing technology, China is capable of developing UHV systems. In order to promote the construction of UHV systems,China Electric Power Research Institute and other institutions have initiated first-phase research activities of UHV transmission technologies. The main contents involve research on UHV transmission technology and its economy,developing and manufacturing abilities on UHV equipment, prospective of UHV network frame and selection of demonstration projects, etc.展开更多
文摘OBE theory focuses on students’learning outcomes and application ability,which is consistent with the requirements of the new curriculum standard.The paper attempts to apply OBE theory to innovate the construction of English classroom teaching mode in senior high schools from aspects of teaching aims,teaching activities,teaching assessments and application activities.Results show that the application of OBE in high schools is beneficial to the development of English teaching and students'learning.
文摘The earth-rockfill dam is one of the primary dam types in the selection of high dams to be constructed in Western China, since it is characterized by favorable adaptability of the dam foundation; full utilization of local earth, rock, and building-excavated materials; low construction cost; and low cement consumption. Many major technical issues regarding earth-rockfill dams with a height of over 250 m were studied and solved successfully in the construction of the 261.5 m Nuozhadu earth core rockfill dam. This paper describes research achievements and basic conclusions; systematically summarizes the accumulated experiences from the construction of the Nuozhadu Dam and other high earth-rockfill dams; and discusses major technical issues, such as deformation control, seepage control, dam slope stability, safety and control of flood discharging, safety and quality control of dam construction, safety assessments, early warning, and other key technical difficulties. This study also provides a reference and technological support for the future construction of 300 m high earth-rockfill dams.
基金National Natural Science Foundation of China(No.50539120)National Basic Research Program of China("973"Program,No. 2007 CB714101)+1 种基金National Science Fund for Distinguished Young Scholars of China(No.50525927)National Natural Science Founda-tion of China(No.50579045)
文摘A method of combining dynamic simulation with real-time control was proposed to fit the randomness and uncertainty in the high arch dam construction process. The mathematical logic model of high arch dam construction process was established. By combining dynamic construction simulation with schedule analysis, the process of construction schedule forecasting and analysis based on dynamic simulation was studied. The process of real-time schedule control was constructed and some measures for dynamic adjustment and control of construction schedule were provided. A system developed with the method is utilized in a being constructed hydroelectric project located at the Yellow River in northwest China, which can make the pouring plan of the dam in the next stage (a month, quarter or year) to guide the practical construction. The application result shows that the system provides an effective technical support for the construction and management of the dam.
基金Project(07031B) supported by the Scientific Research Fund of Central South University of Forestry and Technology
文摘Creep tests under at a certain temperature and different stress levels were performed on two carbon constructional quality steels at a certain stress level and different temperatures,and their creep curves at high temperature were obtained based on analyzing the testing data.Taking 45 steel at a certain temperature and stress as the example,the integral creep constitutive equation and the differential stress-strain constitutive relationship were established based on the relevant rheological model,and the integral core function was also obtained.Simultaneously,the viscous coefficients denoting the viscous behavior in visco-plastic constitutive equation were determined by taking use of the creep testing data.Then the viscous coefficients of three carbon steels(20 steel,35 steel and 45 steel) were compared and analyzed.The results show that the viscosity is different due to different materials at the same temperature and stress.
基金Scientific and Technological Support and Guidance Plan Projects of Zhejiang Province(Grant No.2008C23019)
文摘A self-developed elasto-plastic finite element program was used to analyze the construction sequence of high rock slope's stabilization in a coal-coking plant, and the result was compared with that employing the ultimate equilibrium method. Based on the results of finite element analysis, the stress contour graphs and displacement vector graphs at different construction steps were obtained, and the behavior of the slope during stabilization construction process was analyzed quantitatively. Based on the analysis of safety factors of three different schemes of stabilization and two different construction schemes, the assessment of stability and bracing design of the construction process were performed. The results show that the original reinforcement design is improper; the stability of the rock slope is controlled by a developed structural plane, the stability factor after excavation is less than 1, and the free surface should be braced in time; for stability, the construction sequence should adopt that bracing follows excavation step by step up to down; the local slide occurred during the construction process agrees with the dangerous slide determined by the numerical analysis, which proves the validity and rationality of the adopted method.
基金Supported by the Project of Monitoring System for Farmland Quality Grade of Guangdong Province (2011B020313020)
文摘On the basis of actual situations of Guangdong Province, using Factor Analysis Approach and Quantitative Analysis Method, we built index system by four factors, namely, extent of farmland connectivity, local financial support, grain production capacity and farmland consolidation potential. Finally, we obtained that the areas with total scores of evaluation higher than 50 points are key construction areas of high-standard capital farmland in Guangdong Province. In total, there are 40 key construction areas, including 16 in plain areas of the Pearl River Delta, 9 in coastal regions of east of Guangdong, 10 in coastal regions of west of Guangdong, and 5 in northwest mountainous regions of Guangdong. Besides, we put forward construction direction of these 4 capital farmland areas.
文摘In the process of tunnel construction,if large-deformation occurs in high geostress soft rock,it will likely cause geological disasters.This situation will not only seriously affect the smooth progress of tunnel construction,but also cause serious safety threat to the construction personnel.Therefore,with the continuous growth in the number and scale of tunnel construction in recent years,the construction technology for high geostress soft rock with large-deformation has begun to receive more and more attention from the society.Based on this,this paper takes an actual project as an example to analyze the specific application of the technology in order to improve the construction effect and avoid the damage caused by the large-deformation of the high geostress soft rock.
文摘Massive amounts of limestone waste are produced by the stone processing industry worldwide. Generally, it is believed that 60% to 70% of the stone is wasted in processing in the form of fragments, powder and slurry out of which around 30% is in the form of fine powder [1]. This waste has no beneficial usage and poses environmental hazards. Use of this waste product in the construction industry can largely reduce the amount of waste to be disposed off by the local municipalities in addition to reducing large burden on the environment. Some basic research on use of limestone dust as cement/ concrete filler?has?been carried out in the recent past but high strength/ high performance concretes have not been investigated yet [2] [3]. The concrete industry is among the largest consumer of raw materials worldwide and has been investigated for use of various types of waste materials like crushed brick, rice husk and straw ash as either aggregates for concrete or as partial cement substitutes. Use of limestone dust as filler material in concrete can consume a huge amount of this waste material which has to be disposed off otherwise, creating large burden on the environment. This experimental study aimed at evaluating the properties of high performance concretes made from Portland cement, natural aggregates and sand. Limestone dust was added by replacing sand in the percentages of 10% and 20%. Wide ranging investigations covering most aspects of mechanical behavior and permeability were carried out for various mixes for compressive strengths of 60?N/mm2, 80?N/mm2 and 100?N/mm2. Compressive strengths of concrete specimen with partial replacement of sand with 10% and 20% limestone dust as filler material for 60?N/mm2, 80N/mm2 and 100?N/mm2 were observed to be higher by about 4% to 12% than the control specimen. Flexural strengths were also observed to be higher by 12%?-?13%. Higher elastic moduli and reduced permeability were observed along with better sulphate and acid resistance. Better strengths and improved durability of such high-performance concretes make it a more acceptable material for major construction projects.
文摘At the beginning of 21st century, with the rapid and steady development of China economy, a lot of large scale hydropower projects with large dams from 200 m to 300 m high are being or to be built. China dam constructions are reaching the level of 300 m high arch dam, 250 high CFRD (concrete face rockfill dam) and 200 m high RCC (roller compacted concrete) gravity dam. Due to the safety and the economy, the type selection for high dams has become the key issue during the argumentation for the hydropower projects, and further efforts are still needed in this aspect for high dams. After reviewing the high dam constructions in China and abroad, authors proposed some advices for the selection of dam types, and hope that it can provide some helpful information for the researches and the design of high dams.
文摘The high and large span cast-in-place reinforced concrete cantilever structure of the office building of some court, which is located I-steel at the cantilever and used steel pipe scaffold as the support, has guaranteed the frame body and structure security by the frame body calculating, on-site test and reasonable construction order.
文摘To introduce foreign capital for the municipal highway construction is a great measure to meet the development of the socialist market economy and to reform the investment system for the municipal highway construction. The aim of the reform lies in taking the construction and management of the municipal highway facilities as an industry to operate, widening the investment channel of the municipal highway construction and gradually forming a benign cycle of investment-construc-
文摘In this article, the features of design and construction of Qinhuangdao Shenyang passenger special line in railroad foundation, tracks, and bridges are described as an emphasis, the reasons for success are analyzed, and the recommendations to tackle the exiting issues are presented as the reference in high speed railway construction.
文摘High-speed railways have the merits of high speed, high transport capacity, low consumption of energy, less pollution, less occupation of land, and greater safety. The development of high-speed railways is suitable for the national conditions in China.The authors suggest that, with the Hu-Ning (Shanghai-Nanjing) section of the Jing-Hu (Beijing-Shanghai) Railway as the starting point, a high-speed dedicated passenger railway line be built to realize the separate transportation of passengers and goods, thus easing the strain on transport in East China, accumulating experience for the future development of high-speed railways, and bringing along the development of high and new technology industries.
基金funded by the Science and Technology Department of Guizhou Province (No. [2019]1427)Guizhou Provincial Forestry Department (No. [2017]15)National key research and development program of China (No.2016YFC0502605)
文摘Large-scale transportation infrastructure construction in ecologically vulnerable areas such as the karst region of Southwest China requires estimation method for better project design.This research was carried out on a four-lane highway(the Guilin-Guiyang highway,G76)and a two-lane highspeed railway(the Guilin-Guiyang high-speed railway,GGHSR)in karst areas in Guizhou and Guangxi provinces.The highway and high-speed railway were constructed in the 2010 s and covered by Landsat images whose multispectral information could be used for research purposes.In this study,the severity of the impact and the CO2 emissions from the G76 and GGHSR construction were evaluated.Landsat images and field meteorological measurements were applied to calculate the surface functional parameters(surface temperature and surface wetness)and heat fluxes(latent,sensible and ground heat flux)before and during the highway and high-speed railway construction;the amount of CO2 emissions during the G76 and GGHSR construction were determined by using budget sheets,which record the detail consumptions of materials and energy.The results showed that the decrease of water evaporation from the highway and high-speed railway construction can reach up to 26.4 m3 and 20.1 m3 per kilometer,which corresponds to an average decrease in the vegetation cooling effect of 18.0 MWh per day per highway kilometer and 13.7 MWh per day per high-speed railway kilometer,respectively.At the meantime,the average CO2 emission densities from the G76 and GGHSR construction can reach up to 24813.7 and 36921.1 t/km,respectively.This study implied that extensive line constructions have a significant impact on the local climate and the energy balance,and it is evident that selecting and planting appropriate plant species can compensate for the adverse effects of line constructions in karst mountain regions.
文摘Based on the data of the construction industry in Henan Province, China, from 2005 to 2020, the high-quality development level of the construction industry in Henan Province is measured. Firstly, this paper constructs the indicator system based on the high-quality development theory and the characteristic of the construction industry from seven dimensions: industrial scale, industrial efficiency, industrial benefits, industrial innovation, industrial risk, industrial potential, and the green development of the construction industry. Secondly, using the global principal component analysis (PCA) method to measure the high-quality development level. Thirdly, cluster analysis is applied to measure the relative changes of various dimensions in different stages. The results show that overall the high-quality development level of the construction industry in Henan province is increasing, but different indicators perform differently in various stages, and the changes in real estate policies have a significant impact on this. Finally, based on these findings, we think it is better to reduce real estate dependence, promote the application of new materials and technologies and maintain the stability of real estate policies.
文摘Presents the reverse construction of Harbin Aerospace Building basement,which features improved working conditions,short time of construction,and reduced construction cost.
文摘In order to provide the model point accuracy of ±2 mm,an extra high accuracy industrial control net with four surveying piers with accuracy ±0.1 mm was set up around the model.Tens of orientation marks have been placed on the different parts and measured with accuracy ±0.2 mm from the above_mentioned piers.The main four stereopairs taken with the P31 camera around the model are simultaneously processed on the BC2 analytical plotter.The accuracy of absolute orientation is better than ±0.9 mm.Finally,about 300 sections construction drawings have been directly offered,and the close_range photogrammetric data has been used for the design and construction of the statue.
基金Project (No. 50678157) supported by the National Natural ScienceFoundation of China
文摘Factors such as errors during the fabrication or construction of structural components and errors of calculation as- sumption or calculation methods, are very likely to cause serious deviation of many strings’ actual prestressing forces from the designed values during tension structure construction or service period, and further to threaten the safety and reliability of the structure. Aiming at relatively large errors of the prestressing force of strings in a tension structure construction or service period, this paper proposes a new finite element method (FEM), the "tensile force correction calculation method". Based on the measured prestressing forces of the strings, this new method applies the structure from the zero prestressing force status approach to the measured prestressing force status for the first phase, and from the measured prestressing force status approach to the designed prestressing force status for the second phase. The construction tensile force correction value for each string can be obtained by multi-iteration with FEM. Using the results of calculation, the strings’ tensile force correction by group and in batch will be methodic, simple and accurate. This new calculation method can be applied to the prestressed correction construction simulation analysis for tension structures.
文摘In the tide of China’s reform, opening and modern construction, Shanghai has achieved great success. On his inspection, Deng Xiaoping, the architect of China’s economic reform said," Shanghai has progressed in a year and made great progress in three years." In the 1920s and 1930s, Shanghai was a world economic, financial and trade centre and famed as "the Paris of the Orient."
文摘China needs to develop a strong national power grid which takes ultra-high-voltage (UHV) transmission systems as its core. The grid is expected to adopt 1000-kV-class AC and ± 800-kV DC transmission systems. In view of significant achievements in technological research and considerable progress in UHV manufacturing technology, China is capable of developing UHV systems. In order to promote the construction of UHV systems,China Electric Power Research Institute and other institutions have initiated first-phase research activities of UHV transmission technologies. The main contents involve research on UHV transmission technology and its economy,developing and manufacturing abilities on UHV equipment, prospective of UHV network frame and selection of demonstration projects, etc.