The mechanical properties of the steel-plate-reinforced segmental lining are generally determined by the load-bearing capacity of rein-forced joints.However,there is a lack of valid calculation methods for compression...The mechanical properties of the steel-plate-reinforced segmental lining are generally determined by the load-bearing capacity of rein-forced joints.However,there is a lack of valid calculation methods for compression-bending bearing capacity,and researchers mainly rely on experience and analogy for the design of reinforced joints.This paper proposes an analytical model based on the deformation and stress characteristics of the joint surface to calculate the compression-bending capacity of the steel-plate-reinforced joint.After verifying the applicability of this analytical model through finite element simulations,the evalution rules of the load-bearing capacity of the rein-forced joint were attained,followed by a quantitative investigation into the influence of joint parameters on it.The results show that:(1)the bearing capacity curve of the reinforced joint under different axial forces can be separated into two parts,with the maximum ultimate bending moment found at the demarcation point,where the steel plate yielding and joint failure occur simultaneously;(2)the steel plate strength and cross-sectional area have a strong infuence on the bearing capacity of the reinforced joint when the axial force is under 0.15RFF,where RFF is the axial force at pure-compression failure;(3)the concrete strength and segment width have a prominent influ-ence on the curve when the axial force is over 0.30RFF;(4)the impact of the fictitious strain,bolt strength,bolt diameter,and bolt loca-tion on the bearing capacity is minimal in range and amplitude.展开更多
Exploitation and utilization of urban underground space resources is gaining increasing attention in cities’sustainable development.Due to the attributes of fragility and irreversibility,urban underground space resou...Exploitation and utilization of urban underground space resources is gaining increasing attention in cities’sustainable development.Due to the attributes of fragility and irreversibility,urban underground space resources can be extremely vulnerable to damage and it is often difficult in restoring their original state once damaged.Therefore,scientific and reasonable evaluation of urban underground space resources is of vital importance in urban planning and development.This paper first describes the content and methods for the evaluation of urban underground space resources,and introduces the digitalization technologies to handle the problems of strong subjectivity,low efficiency and rough precision encountered when using traditional evaluation tools.Then,the related concepts and main technologies for digitalization were demonstrated and an intelligent GIS-based engineering geology system was built.Based on the drilling information in Changzhou City,stratum standardization and 3D modeling of strata,underground structures and pipelines were conducted in the built intelligent system.Finally,with the help of spatial overlay analysis in the GIS-based platform and a combination of other digitalization technologies,the urban underground space resources of Changzhou City were evaluated.Maps of geological suitability were produced,which provide scientific guidance and reference for the exploitation and planning of urban underground space resources in Changzhou City.In addition,site selection for key projects was conducted based on the evaluation results using this platform.展开更多
基金support provided by the National Natural Science Foundation of China(Grant No.52278409).
文摘The mechanical properties of the steel-plate-reinforced segmental lining are generally determined by the load-bearing capacity of rein-forced joints.However,there is a lack of valid calculation methods for compression-bending bearing capacity,and researchers mainly rely on experience and analogy for the design of reinforced joints.This paper proposes an analytical model based on the deformation and stress characteristics of the joint surface to calculate the compression-bending capacity of the steel-plate-reinforced joint.After verifying the applicability of this analytical model through finite element simulations,the evalution rules of the load-bearing capacity of the rein-forced joint were attained,followed by a quantitative investigation into the influence of joint parameters on it.The results show that:(1)the bearing capacity curve of the reinforced joint under different axial forces can be separated into two parts,with the maximum ultimate bending moment found at the demarcation point,where the steel plate yielding and joint failure occur simultaneously;(2)the steel plate strength and cross-sectional area have a strong infuence on the bearing capacity of the reinforced joint when the axial force is under 0.15RFF,where RFF is the axial force at pure-compression failure;(3)the concrete strength and segment width have a prominent influ-ence on the curve when the axial force is over 0.30RFF;(4)the impact of the fictitious strain,bolt strength,bolt diameter,and bolt loca-tion on the bearing capacity is minimal in range and amplitude.
基金This study is supported by China National Engineering Institute’s Consulting Project(grant No.2015-XZ-16-01)National Basic Research Program of China(973 Program)(grant No.2011CB013800).We gratefully acknowledge Changzhou Urban Planning Bureau,Changzhou City Planning and Design Institute,Shanghai Tongyan Civil Engineering Technology Co.,Ltd.and Nanjing University for their valuable cooperation in performing the evaluation of urban underground space resources in Changzhou City.
文摘Exploitation and utilization of urban underground space resources is gaining increasing attention in cities’sustainable development.Due to the attributes of fragility and irreversibility,urban underground space resources can be extremely vulnerable to damage and it is often difficult in restoring their original state once damaged.Therefore,scientific and reasonable evaluation of urban underground space resources is of vital importance in urban planning and development.This paper first describes the content and methods for the evaluation of urban underground space resources,and introduces the digitalization technologies to handle the problems of strong subjectivity,low efficiency and rough precision encountered when using traditional evaluation tools.Then,the related concepts and main technologies for digitalization were demonstrated and an intelligent GIS-based engineering geology system was built.Based on the drilling information in Changzhou City,stratum standardization and 3D modeling of strata,underground structures and pipelines were conducted in the built intelligent system.Finally,with the help of spatial overlay analysis in the GIS-based platform and a combination of other digitalization technologies,the urban underground space resources of Changzhou City were evaluated.Maps of geological suitability were produced,which provide scientific guidance and reference for the exploitation and planning of urban underground space resources in Changzhou City.In addition,site selection for key projects was conducted based on the evaluation results using this platform.
