With the continuous development of today's construction industry, the construction of underground engineering is becoming more and more common. Especially with the accelerating process of urbanization, more and mo...With the continuous development of today's construction industry, the construction of underground engineering is becoming more and more common. Especially with the accelerating process of urbanization, more and more construction projects and underground projects begin to develop in the direction of ultra-deep and multi-layered. However, under the influence of groundwater, the underground building engineering structure will be subject to greater buoyancy, and this buoyancy will increase with the buried depth of the underground building structure, which will lead to the floating of the bottom plate and wall. In serious cases, there will even be building overturning, which will bring a great security threat to the construction engineering. In order to ensure the anti- floating ability of underground engineering, the anti-floating design and control measures are analyzed in this paper. It is hoped that this analysis can lay a good foundation for the improvement of anti-floating performance of underground construction engineering, so as to ensure the quality and safety of the overall construction engineering.展开更多
Purpose–This paper aims to study the impacts of groundwater seepage on artificial freezing process of gravel strata,the temperature field characteristics of the strata,and the strata process,closure time and thicknes...Purpose–This paper aims to study the impacts of groundwater seepage on artificial freezing process of gravel strata,the temperature field characteristics of the strata,and the strata process,closure time and thickness evolution mechanism of the frozen wall.Design/methodology/approach–In this paper several laboratory model tests were conducted,considering different groundwater seepage rate.Findings–The results show that there is a significant coupling effect between the cold diffusion of artificial freezing pipes and groundwater seepage;when there is no seepage,temperature fields upstream and downstream of the gravel strata are symmetrically distributed,and the thickness of the frozen soil column/frozen wall is consistent during artificial freezing;groundwater seepage causes significant asymmetry in the temperature fields upstream and downstream of the gravel strata,and the greater the seepage rate,the more obvious the asymmetry;the frozen wall closure time increases linearly with the increase in the groundwater seepage rate,and specifically,the time length under seepage rate of 5.00 m d1 is 3.2 times longer than that under no seepage;due to the erosion from groundwater seepage,the thickness of the upstream frozen wall decreases linearly with the seepage velocity,while that of the downstream frozen wall increases linearly,resulting in a saddle-shaped frozen wall.Originality/value–The research results are beneficial to the optimum design and risk control of artificial freezing process in gravel strata.展开更多
With 200 km of new lines and 68 new stations,the Grand Paris Express(GPE)project is currently the biggest transport project under construction in Europe.Starting in 2010,the GPE project involves an ambitious schedule ...With 200 km of new lines and 68 new stations,the Grand Paris Express(GPE)project is currently the biggest transport project under construction in Europe.Starting in 2010,the GPE project involves an ambitious schedule with major milestones planned between 2022 and 2030.To meet these deadlines as well as the associated cost,quality and safety goals,intensive construction technology is needed in this once-in-a-century megaproject,but this project also provides ideal opportunities to apply this technology.This paper offers a review of the new and innovative construction technologies used during the GPE project’s design and construction stages.Such a large project certainly presents a range of complexities and poses many technical,material,human and environmental challenges.Due to its high-risk nature,the risk management plan that applies throughout the whole GPE project,along with the contractual and insurance conditions,is introduced first.Then,an overview is provided of the design principles and construction methods selected to overcome the engineering challenges and reduce the technical risks,all of which are accompanied by monitoring methods and digital approaches.In addition,several new and innovative construction technologies adopted in this project are illustrated.The paper concludes with the project’s environmental protection.展开更多
文摘With the continuous development of today's construction industry, the construction of underground engineering is becoming more and more common. Especially with the accelerating process of urbanization, more and more construction projects and underground projects begin to develop in the direction of ultra-deep and multi-layered. However, under the influence of groundwater, the underground building engineering structure will be subject to greater buoyancy, and this buoyancy will increase with the buried depth of the underground building structure, which will lead to the floating of the bottom plate and wall. In serious cases, there will even be building overturning, which will bring a great security threat to the construction engineering. In order to ensure the anti- floating ability of underground engineering, the anti-floating design and control measures are analyzed in this paper. It is hoped that this analysis can lay a good foundation for the improvement of anti-floating performance of underground construction engineering, so as to ensure the quality and safety of the overall construction engineering.
基金supported by the National Natural Science Foundation of China(Grant No.51978426)the NSFC Young Scientists Fund(Grant No.41801277)+1 种基金the Science and Technology Research Program of Hebei Education Department(Grant No.QN2018072)the Program for High-level Talent Fund of Hebei Province(Grant No.A201903010).
文摘Purpose–This paper aims to study the impacts of groundwater seepage on artificial freezing process of gravel strata,the temperature field characteristics of the strata,and the strata process,closure time and thickness evolution mechanism of the frozen wall.Design/methodology/approach–In this paper several laboratory model tests were conducted,considering different groundwater seepage rate.Findings–The results show that there is a significant coupling effect between the cold diffusion of artificial freezing pipes and groundwater seepage;when there is no seepage,temperature fields upstream and downstream of the gravel strata are symmetrically distributed,and the thickness of the frozen soil column/frozen wall is consistent during artificial freezing;groundwater seepage causes significant asymmetry in the temperature fields upstream and downstream of the gravel strata,and the greater the seepage rate,the more obvious the asymmetry;the frozen wall closure time increases linearly with the increase in the groundwater seepage rate,and specifically,the time length under seepage rate of 5.00 m d1 is 3.2 times longer than that under no seepage;due to the erosion from groundwater seepage,the thickness of the upstream frozen wall decreases linearly with the seepage velocity,while that of the downstream frozen wall increases linearly,resulting in a saddle-shaped frozen wall.Originality/value–The research results are beneficial to the optimum design and risk control of artificial freezing process in gravel strata.
文摘With 200 km of new lines and 68 new stations,the Grand Paris Express(GPE)project is currently the biggest transport project under construction in Europe.Starting in 2010,the GPE project involves an ambitious schedule with major milestones planned between 2022 and 2030.To meet these deadlines as well as the associated cost,quality and safety goals,intensive construction technology is needed in this once-in-a-century megaproject,but this project also provides ideal opportunities to apply this technology.This paper offers a review of the new and innovative construction technologies used during the GPE project’s design and construction stages.Such a large project certainly presents a range of complexities and poses many technical,material,human and environmental challenges.Due to its high-risk nature,the risk management plan that applies throughout the whole GPE project,along with the contractual and insurance conditions,is introduced first.Then,an overview is provided of the design principles and construction methods selected to overcome the engineering challenges and reduce the technical risks,all of which are accompanied by monitoring methods and digital approaches.In addition,several new and innovative construction technologies adopted in this project are illustrated.The paper concludes with the project’s environmental protection.
