In order to improve the design method of steel fiber reinforced concrete segment without rebars and accelerate its application in urban rail transit,a new design method of normal section structure of steel fiber reinforced concrete segment without rebars was proposed.According to the previous research results on the constitutive relationship of steel fiber concrete and the stress characteristics of subway segments,the main factors affecting the bearing capacity of the subway segments'normal section were analyzed.Based on the difference in order of magnitude between the ultimate tensile strain of the steel fiber reinforced concrete segment without rebars and the ultimate tensile strain of reinforced concrete,and combining with current concrete specifications and the assumption of plane deformation of the cross section,the stress and strain were taken as the characteristic values of the design of steel fiber reinforced concrete segments without rebars.The range of strain of the steel fiber reinforced concrete corresponds to different design conditions,the calculation results of steel fiber reinforced concrete segments without rebars under different working conditions were summarized into a same stress-strain diagram.The calculation flow of the axial cross section design using the axial force-bending moment envelope diagram was presented,and the relationship between the axial force-bending moment envelope diagrams of steel fiber reinforced concrete without rebars under different working conditions was shown through an engineering practice.The calculation results show that strength is the main factor that affects the bearing capacity under serviceability limit state,and toughness of the steel fiber reinforced concrete without rebars is the main factor that affects the bearing capacity under ultimate capacity state,especially under accidental loading.
关键词
无筋钢纤维混凝土/正截面结构设计/正常使用极限状态/承载能力极限状态
Key words
steel fiber reinforced concrete without rebars/normal section structural design/normal service limit state/ultimate state of bearing capacity
维普
万方数据