To fully leverage the advantages of mechanization and informatization in tunnel boring machine(TBM)operations,the authors aim to promote the advancement of tunnel construction technology toward intelligent development...To fully leverage the advantages of mechanization and informatization in tunnel boring machine(TBM)operations,the authors aim to promote the advancement of tunnel construction technology toward intelligent development.This involved exploring the deep integration of next-generation artificial intelligence technologies,such as sensing technology,automatic control technology,big data technology,deep learning,and machine vision,with key operational processes,including TBM excavation,direction adjustment,step changes,inverted arch block assembly,material transportation,and operation status assurance.The results of this integration are summarized as follows.(1)TBM key excavation parameter prediction algorithm was developed with an accuracy rate exceeding 90%.The TBM intelligent step-change control algorithm,based on machine vision,achieved an image segmentation accuracy rate of 95%and gripper shoe positioning error of±5 mm.(2)An automatic positioning system for inverted arch blocks was developed,enabling real-time perception of the spatial position and deviation during the assembly process.The system maintains an elevation positioning deviation within±3 mm and a horizontal positioning deviation within±10 mm,reducing the number of surveyors in each work team.(3)A TBM intelligent rail transportation system that achieves real-time human-machine positioning,automatic switch opening and closing,automatic obstacle avoidance,intelligent transportation planning,and integrated scheduling and command was designed.Each locomotive formation reduces one shunter and improves comprehensive transportation efficiency by more than 20%.(4)Intelligent analysis and prediction algorithms were developed to monitor and predict the trends of the hydraulic and gear oil parameters in real time,enhancing the proactive maintenance and system reliability.展开更多
The advent of parametric design has resulted in a marked increase in the complexity of building.Unfortunately,traditional construction methods make it difficult to meet the needs.Therefore,construction robots have bec...The advent of parametric design has resulted in a marked increase in the complexity of building.Unfortunately,traditional construction methods make it difficult to meet the needs.Therefore,construction robots have become a pivotal production tool in this context.Since the arm span of a single robot usually does not exceed 3 meters,it is not competent for producing large-scale building components.Accordingly,the extension of the robot,s working range is often achieved by external axes.Nevertheless,the coupling control of external axes and robots and their kinematic solution have become key challenges.The primary technical difficulties include customized construction robots,automatic solutions for external axes,fixed axis joints,and specific motion mode control.This paper proposes solutions to these difficulties,introduces the relevant basic concepts and algorithms in detail,and encapsulates these robotics principles and algorithm processes into the Grasshopper plug-in commonly used by architects to form the FURobot software platform.This platform effectively solves the above problems,lowers the threshold for architects,and improves production efficiency.The effectiveness of the algorithm and software in this paper is verified through simulation experiments.展开更多
Urban growth has promoted the use of underground spaces,where explosion accidents can be catastrophic.In this study,we investigated the effect of placing flexible construction in front of rigid obstacles on methane ex...Urban growth has promoted the use of underground spaces,where explosion accidents can be catastrophic.In this study,we investigated the effect of placing flexible construction in front of rigid obstacles on methane explosion protection by using an experimental platform and adjusting the blockage rate and spacing of the obstacles.It aims to reduce the risk of gas explosions in urban underground spaces.The results of the study show that the flame propagation peak speed and peak overpressure are reduced with the decrease in the blocking rate of the flexible obstacle when the blocking rate of the flexible obstacle is less than or equal to the blocking rate of the rigid obstacle,with the decrease in the spacing,the better the protection effect of the methane explosion.When the blockage rate of the flexible obstacle is greater than the blockage rate of the rigid obstacle and spacing is less than the height of the flexible obstacle,rigid and flexible obstacles are connected as a whole,increasing the strength of the explosion.This study can provide a theoretical basis and scientific guidance for optimizing rigid and flexible object hybrid layouts and methane explosion protection technology in urban underground spaces.展开更多
The process of urbanization affects the urban warming.The change of urban warming was investigated by several urbanization factors in Changsha,China.The data of surface temperature(minimum,maximum and mean) of Changsh...The process of urbanization affects the urban warming.The change of urban warming was investigated by several urbanization factors in Changsha,China.The data of surface temperature(minimum,maximum and mean) of Changsha were analyzed to understand the possible effects of urbanization on the climate of this region owing to the population growth,built-up area expansion and energy consumption increases.The weights of these three factors were calculated by the analytical hierarchy process(AHP).Then,three weights were simulated with nonlinear method to obtain the urbanization development rate which was utilized to reveal the influence of the urbanization factors on the surface temperature.The result shows that there is a significant upward trend in the urban temperatures of Changsha.The temperature increase seems to be closely related to the rate of urbanization between 1993 and 2008,and there is an evidential increase trend of the influence on urban temperature by urbanization during 16 years.It is a quantifiable approach measuring the relationship between urbanization and urban eco-environment,and can be applied for the urban sustainability.展开更多
Completing the principal engineering components of a pumped storage power station spans between 50 and 60 months,from the inception of construction to the commencement of power generation by the first unit.The filling...Completing the principal engineering components of a pumped storage power station spans between 50 and 60 months,from the inception of construction to the commencement of power generation by the first unit.The filling of the penstock with water represents a critical phase preceding the production of electricity by the first unit.During this interval,the construction of the diversion shaft presents multiple challenges,including intricate construction procedures,considerable construction difficulty,elevated safety risks,and quality control issues.To address this issue,this study uses CFD software to analyze the flow field,pressure gradient,and head loss of shaft curved section with different curvature radius,and examines several key technologies by drawing on the practice of diversion shaft construction at the Meizhou pumped storage power station.These technologies include optimizing the curvature radius of the curved section of diversion shaft,reverse-well excavation for the shaft,and sliding-up for the lining concrete.It is found that as the curvature radius of shaft curved section reduces from 4 to 2 times the shaft diameter,the hydraulic characteristic index does not change much,and the increase of head loss accounts for about 0.18%of the total head loss of the water conveyance system.The result show that optimizing the curvature radius from 4 times to 2 times the shaft diameter is feasible and reasonable,and several improved technical measures have been proposed,such as stabilizing drill rods,mechanical scraper systems,and control technology of the relationship between concrete setting time and formwork sliding.Their implementation effectively mitigates difficulties and safety risks during shaft construction,expedites the project schedule,enhances engineering quality,and creates a 41-month timeline for the principal engineering schedule for the first power unit generation in China.展开更多
文摘To fully leverage the advantages of mechanization and informatization in tunnel boring machine(TBM)operations,the authors aim to promote the advancement of tunnel construction technology toward intelligent development.This involved exploring the deep integration of next-generation artificial intelligence technologies,such as sensing technology,automatic control technology,big data technology,deep learning,and machine vision,with key operational processes,including TBM excavation,direction adjustment,step changes,inverted arch block assembly,material transportation,and operation status assurance.The results of this integration are summarized as follows.(1)TBM key excavation parameter prediction algorithm was developed with an accuracy rate exceeding 90%.The TBM intelligent step-change control algorithm,based on machine vision,achieved an image segmentation accuracy rate of 95%and gripper shoe positioning error of±5 mm.(2)An automatic positioning system for inverted arch blocks was developed,enabling real-time perception of the spatial position and deviation during the assembly process.The system maintains an elevation positioning deviation within±3 mm and a horizontal positioning deviation within±10 mm,reducing the number of surveyors in each work team.(3)A TBM intelligent rail transportation system that achieves real-time human-machine positioning,automatic switch opening and closing,automatic obstacle avoidance,intelligent transportation planning,and integrated scheduling and command was designed.Each locomotive formation reduces one shunter and improves comprehensive transportation efficiency by more than 20%.(4)Intelligent analysis and prediction algorithms were developed to monitor and predict the trends of the hydraulic and gear oil parameters in real time,enhancing the proactive maintenance and system reliability.
基金National Key R&D Program of China(Nos.2023YFC3806900,2022YFE0141400)。
文摘The advent of parametric design has resulted in a marked increase in the complexity of building.Unfortunately,traditional construction methods make it difficult to meet the needs.Therefore,construction robots have become a pivotal production tool in this context.Since the arm span of a single robot usually does not exceed 3 meters,it is not competent for producing large-scale building components.Accordingly,the extension of the robot,s working range is often achieved by external axes.Nevertheless,the coupling control of external axes and robots and their kinematic solution have become key challenges.The primary technical difficulties include customized construction robots,automatic solutions for external axes,fixed axis joints,and specific motion mode control.This paper proposes solutions to these difficulties,introduces the relevant basic concepts and algorithms in detail,and encapsulates these robotics principles and algorithm processes into the Grasshopper plug-in commonly used by architects to form the FURobot software platform.This platform effectively solves the above problems,lowers the threshold for architects,and improves production efficiency.The effectiveness of the algorithm and software in this paper is verified through simulation experiments.
基金supported by the National Natural Science Foundation of China(Grant No.52274177)Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJZD-K202401501)+1 种基金Chongqing Graduate Student Research Innovation Program(Grant No.CYS240800)The Science and Technology Innovation Project for Graduate Students of Chongqing University of Science and Technology(Grant No.YKJCX2420702).
文摘Urban growth has promoted the use of underground spaces,where explosion accidents can be catastrophic.In this study,we investigated the effect of placing flexible construction in front of rigid obstacles on methane explosion protection by using an experimental platform and adjusting the blockage rate and spacing of the obstacles.It aims to reduce the risk of gas explosions in urban underground spaces.The results of the study show that the flame propagation peak speed and peak overpressure are reduced with the decrease in the blocking rate of the flexible obstacle when the blocking rate of the flexible obstacle is less than or equal to the blocking rate of the rigid obstacle,with the decrease in the spacing,the better the protection effect of the methane explosion.When the blockage rate of the flexible obstacle is greater than the blockage rate of the rigid obstacle and spacing is less than the height of the flexible obstacle,rigid and flexible obstacles are connected as a whole,increasing the strength of the explosion.This study can provide a theoretical basis and scientific guidance for optimizing rigid and flexible object hybrid layouts and methane explosion protection technology in urban underground spaces.
基金Projects(2008JT1013,2007JT3018,05SK3002) supported by the Key Program for Science and Technology in Hunan Province,ChinaProject(2007ZK2025) supported by the Key Program for Soft Science in Hunan Province,China
文摘The process of urbanization affects the urban warming.The change of urban warming was investigated by several urbanization factors in Changsha,China.The data of surface temperature(minimum,maximum and mean) of Changsha were analyzed to understand the possible effects of urbanization on the climate of this region owing to the population growth,built-up area expansion and energy consumption increases.The weights of these three factors were calculated by the analytical hierarchy process(AHP).Then,three weights were simulated with nonlinear method to obtain the urbanization development rate which was utilized to reveal the influence of the urbanization factors on the surface temperature.The result shows that there is a significant upward trend in the urban temperatures of Changsha.The temperature increase seems to be closely related to the rate of urbanization between 1993 and 2008,and there is an evidential increase trend of the influence on urban temperature by urbanization during 16 years.It is a quantifiable approach measuring the relationship between urbanization and urban eco-environment,and can be applied for the urban sustainability.
文摘Completing the principal engineering components of a pumped storage power station spans between 50 and 60 months,from the inception of construction to the commencement of power generation by the first unit.The filling of the penstock with water represents a critical phase preceding the production of electricity by the first unit.During this interval,the construction of the diversion shaft presents multiple challenges,including intricate construction procedures,considerable construction difficulty,elevated safety risks,and quality control issues.To address this issue,this study uses CFD software to analyze the flow field,pressure gradient,and head loss of shaft curved section with different curvature radius,and examines several key technologies by drawing on the practice of diversion shaft construction at the Meizhou pumped storage power station.These technologies include optimizing the curvature radius of the curved section of diversion shaft,reverse-well excavation for the shaft,and sliding-up for the lining concrete.It is found that as the curvature radius of shaft curved section reduces from 4 to 2 times the shaft diameter,the hydraulic characteristic index does not change much,and the increase of head loss accounts for about 0.18%of the total head loss of the water conveyance system.The result show that optimizing the curvature radius from 4 times to 2 times the shaft diameter is feasible and reasonable,and several improved technical measures have been proposed,such as stabilizing drill rods,mechanical scraper systems,and control technology of the relationship between concrete setting time and formwork sliding.Their implementation effectively mitigates difficulties and safety risks during shaft construction,expedites the project schedule,enhances engineering quality,and creates a 41-month timeline for the principal engineering schedule for the first power unit generation in China.
