With the acceleration of urbanization,prefabricated bridges have become a significant choice for transportation infrastructure construction due to their environmental friendliness,efficiency,and reliable quality.Howev...With the acceleration of urbanization,prefabricated bridges have become a significant choice for transportation infrastructure construction due to their environmental friendliness,efficiency,and reliable quality.However,existing connection technologies still face shortcomings in construction efficiency,seismic performance,and cost control.This paper summarizes the process characteristics of commonly used connection technologies such as socket connections,grouted sleeve connections and corrugated pipe connections,and analyzes their seismic capacity and mechanical performance.In response to existing issues,two new technologies—separated steel connection and multi-chamber steel tube concrete connection—are proposed,and their comprehensive performance and economic efficiency are analyzed.The new connection technologies outperform traditional methods in construction efficiency,economic efficiency,and structural stability,with more reasonable force distribution,clearer load transfer paths,and significantly reduced overall costs.Existing technologies,such as socket connections,perform well in seismic performance but are complex to construct;grouted sleeve connections are mature in technology,but the quality of grouting is difficult to inspect.The separated steel connection and multi-chamber steel tube concrete connection technologies offer significant advantages.With the increasing demands for energy conservation and emission reduction,coupled with the rising labor costs,prefabricated bridge piers are undoubtedly poised to become one of the preferred technologies for bridge construction in China in the future.Therefore,in light of the current research landscape,this paper concludes by offering a forward-looking perspective on the development directions of connection methods for prefabricated bridge piers and identifying key areas for future research.展开更多
Using total suspended solid （TSS） removal efficiency and hydraulic retention time （HRT） as design parameters a design guideline of a settling basin in a constructed wetland （CW） was suggested; as well as managem...Using total suspended solid （TSS） removal efficiency and hydraulic retention time （HRT） as design parameters a design guideline of a settling basin in a constructed wetland （CW） was suggested; as well as management of sediment and particle in the settling basin. The CW was desiEned to treat the piggery wastewater effluent from a wastewater treatment plant during dry days and stonnwater runoff from the surrounding paved area during wet days. The first settling basin （FSB） in the CVV was theoretically designed with a total storage volume （TSV） of 453 ms and HRT of 5.5 hr. The amount of sediment and particles settled at the FSB was high due to the sedimentation and interception of plants in the CVV. Dredging of sediments was performed when the retention rate at the FSB decreased to approximately 80%. Findings showed that the mean flow rate was 21.8 m3/hr less than the designed flow rate of 82.8 m3/hr indicating that the FSB was oversize and operated with longer HRT （20.7 hr） compared to the design HRT. An empirical model to estimate the length of the settling basin in the CW was developed as a function of HRT and desired TSS removal efficiency. Using the minimum tolerable TSS removal efficiency of 30%, the length of the FSB was estimated to be 31.2 m with 11.8 hr HRT.展开更多
Construction site layout planning(CSLP)involves strategically placing various facilities to optimize a project.However,real construction sites are complex,making it challenging to consider all construction activities ...Construction site layout planning(CSLP)involves strategically placing various facilities to optimize a project.However,real construction sites are complex,making it challenging to consider all construction activities and facilities comprehensively.Addressing multi-objective layout optimization is crucial for CSLP.Previous optimization results often lacked precision,imposed stringent boundary constraints,and had limited applications in prefabricated construction.Traditional heuristic algorithms still require improvements in region search strategies and computational efficiency when tackling multi-objective optimization problems.This paper optimizes the prefabricated component construction site layout planning(PCCSLP)by treating construction efficiency and safety risk as objectives within a multi-objective CSLP model.A novel heuristic algorithm,the Hybrid Multi-Strategy Improvement Dung Beetle Optimizer(HMSIDBO),was applied to solve the model due to its balanced capabilities in global exploration and local development.The practicality and effectiveness of this approach were validated through a case study in prefabricated residential construction.The research findings indicate that the HMSIDBO-PCCSLP optimization scheme improved each objective by 18%to 75%compared to the original layout.Compared to Genetic Algorithm(GA),the HMSIDBO demonstrates significantly faster computational speed and higher resolution accuracy.Additionally,in comparison with the Dung Beetle Optimizer(DBO),Particle Swarm Optimization(PSO),and Whale Optimization Algorithm(WOA),HMSIDBO exhibits superior iterative speed and an enhanced ability for global exploration.This paper completes the framework from data collection to multi-objective optimization in-site layout,laying the foundation for implementing intelligent construction site layout practices.展开更多
On May 26,the largeLNG carrier No.2"Al Rahba",jointly built by Jiangnan Shipbuilding and China Shipbuilding Trading(CST)both under CSSC,was officially delivered to Abu Dhabi National Oil Company.The construc...On May 26,the largeLNG carrier No.2"Al Rahba",jointly built by Jiangnan Shipbuilding and China Shipbuilding Trading(CST)both under CSSC,was officially delivered to Abu Dhabi National Oil Company.The construction period of the ship is further shortened compared with the first ship delivered in November last year,indicating that Jiangnan Shipbuilding has not only formed the batch delivery capacity of large LNG carriers,but also ranks among the world's leading camp in terms of construction level and effiriency.展开更多
Developing photovoltaic(PV)cells for harvesting renewable and clean solar energy is a promising strategy to meet the growing energy demand.Perovskite solar cells(PSCs),as a new player in the photovoltaic field,exhibit...Developing photovoltaic(PV)cells for harvesting renewable and clean solar energy is a promising strategy to meet the growing energy demand.Perovskite solar cells(PSCs),as a new player in the photovoltaic field,exhibit rapid development with an original power conversion efficiency(PCE)of 3.81%in 2009,a promising PCE of over 20%in 2014 and a record PCE of 22.1%in展开更多
基金supported by Prevention the Fundamental Research Funds for the Central Universities“Study on the general joint of prefabricated high-pier columns”(ZY20230218)Science and Technology Innovation Program for Postgraduate students in IDP subsidized by Fundamental Research Funds for the Central Universities“Research on seismic performance of prefabricated bridge piers with embedded separated steel connections”(ZY20250316).
文摘With the acceleration of urbanization,prefabricated bridges have become a significant choice for transportation infrastructure construction due to their environmental friendliness,efficiency,and reliable quality.However,existing connection technologies still face shortcomings in construction efficiency,seismic performance,and cost control.This paper summarizes the process characteristics of commonly used connection technologies such as socket connections,grouted sleeve connections and corrugated pipe connections,and analyzes their seismic capacity and mechanical performance.In response to existing issues,two new technologies—separated steel connection and multi-chamber steel tube concrete connection—are proposed,and their comprehensive performance and economic efficiency are analyzed.The new connection technologies outperform traditional methods in construction efficiency,economic efficiency,and structural stability,with more reasonable force distribution,clearer load transfer paths,and significantly reduced overall costs.Existing technologies,such as socket connections,perform well in seismic performance but are complex to construct;grouted sleeve connections are mature in technology,but the quality of grouting is difficult to inspect.The separated steel connection and multi-chamber steel tube concrete connection technologies offer significant advantages.With the increasing demands for energy conservation and emission reduction,coupled with the rising labor costs,prefabricated bridge piers are undoubtedly poised to become one of the preferred technologies for bridge construction in China in the future.Therefore,in light of the current research landscape,this paper concludes by offering a forward-looking perspective on the development directions of connection methods for prefabricated bridge piers and identifying key areas for future research.
基金supported by a grant (Code # 413-111-004) from Eco Innovation Project funded by Ministry of Environment of Korea government
文摘Using total suspended solid （TSS） removal efficiency and hydraulic retention time （HRT） as design parameters a design guideline of a settling basin in a constructed wetland （CW） was suggested; as well as management of sediment and particle in the settling basin. The CW was desiEned to treat the piggery wastewater effluent from a wastewater treatment plant during dry days and stonnwater runoff from the surrounding paved area during wet days. The first settling basin （FSB） in the CVV was theoretically designed with a total storage volume （TSV） of 453 ms and HRT of 5.5 hr. The amount of sediment and particles settled at the FSB was high due to the sedimentation and interception of plants in the CVV. Dredging of sediments was performed when the retention rate at the FSB decreased to approximately 80%. Findings showed that the mean flow rate was 21.8 m3/hr less than the designed flow rate of 82.8 m3/hr indicating that the FSB was oversize and operated with longer HRT （20.7 hr） compared to the design HRT. An empirical model to estimate the length of the settling basin in the CW was developed as a function of HRT and desired TSS removal efficiency. Using the minimum tolerable TSS removal efficiency of 30%, the length of the FSB was estimated to be 31.2 m with 11.8 hr HRT.
基金supported by the National Key R&D projects(Grant No.2018YFC0704301)Science and Technology Project of Wuhan Urban and Rural Construction Bureau,China(201943)+2 种基金Research on theory and application of prefabricated building construction management(20201h0439)Wuhan Modou Construction Consulting Co.,Ltd.(20201h0414)Preliminary Study on the Preparation of the 14th Five-Year Plan for Housing and Urban-Rural Development in Hubei Province,China(20202s002).
文摘Construction site layout planning(CSLP)involves strategically placing various facilities to optimize a project.However,real construction sites are complex,making it challenging to consider all construction activities and facilities comprehensively.Addressing multi-objective layout optimization is crucial for CSLP.Previous optimization results often lacked precision,imposed stringent boundary constraints,and had limited applications in prefabricated construction.Traditional heuristic algorithms still require improvements in region search strategies and computational efficiency when tackling multi-objective optimization problems.This paper optimizes the prefabricated component construction site layout planning(PCCSLP)by treating construction efficiency and safety risk as objectives within a multi-objective CSLP model.A novel heuristic algorithm,the Hybrid Multi-Strategy Improvement Dung Beetle Optimizer(HMSIDBO),was applied to solve the model due to its balanced capabilities in global exploration and local development.The practicality and effectiveness of this approach were validated through a case study in prefabricated residential construction.The research findings indicate that the HMSIDBO-PCCSLP optimization scheme improved each objective by 18%to 75%compared to the original layout.Compared to Genetic Algorithm(GA),the HMSIDBO demonstrates significantly faster computational speed and higher resolution accuracy.Additionally,in comparison with the Dung Beetle Optimizer(DBO),Particle Swarm Optimization(PSO),and Whale Optimization Algorithm(WOA),HMSIDBO exhibits superior iterative speed and an enhanced ability for global exploration.This paper completes the framework from data collection to multi-objective optimization in-site layout,laying the foundation for implementing intelligent construction site layout practices.
文摘On May 26,the largeLNG carrier No.2"Al Rahba",jointly built by Jiangnan Shipbuilding and China Shipbuilding Trading(CST)both under CSSC,was officially delivered to Abu Dhabi National Oil Company.The construction period of the ship is further shortened compared with the first ship delivered in November last year,indicating that Jiangnan Shipbuilding has not only formed the batch delivery capacity of large LNG carriers,but also ranks among the world's leading camp in terms of construction level and effiriency.
文摘Developing photovoltaic(PV)cells for harvesting renewable and clean solar energy is a promising strategy to meet the growing energy demand.Perovskite solar cells(PSCs),as a new player in the photovoltaic field,exhibit rapid development with an original power conversion efficiency(PCE)of 3.81%in 2009,a promising PCE of over 20%in 2014 and a record PCE of 22.1%in
