Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Experimental and numerical study on seismic response of inclined tower legs of cable-stayed bridges during earthquakes
https://orcid.org/0000-0001-8341-5903
Highlights A scaled bridge model was tested to study seismic response of inclined tower legs. A numerical model with multi-linear torsional stiffness was established. Bending and torsion together caused the damage of inclined tower legs. An elastic stiffness of torsion led to inaccurate torsional response.
Abstract More than half of cable-stayed bridges adopt the tower with inclined legs, which can be loaded with a combination of bending, torsion, shear and axial force under earthquakes. To study the seismic response of inclined tower legs, shake table tests were conducted on a 1/20 scaled cable-stayed bridge model with an inverted Y-shaped tower. A description of the model design was introduced and observed damages including horizontal and diagonal cracks at inclined tower legs were presented. A numerical model, considering reduction of torsional stiffness of inclined tower legs after diagonal cracking, was established. The feasibility of the numerical model was validated by a comparison of numerical and test results, which showed good correlation in displacement response at tower top and deck end, and cable force. Based on numerical results, the crack torsional moment of the inclined tower could be easily reached at small peak ground acceleration (PGA), leading to a substantial reduction of torsional stiffness of the section. This reduction helped alleviate the torsional moment demand at larger PGAs and delay the torsional failure of the tower legs. Numerical results also revealed that the bending moment is the primary factor to cause concrete cracks at the lower regions of inclined tower legs whereas complex interaction of large bending moment and torsion results in flexural and torsional damage near the intersection. Conventional ways, which adopt an elastic behavior of torsion, either using stiffness prior to or after diagonal cracking, will lead to intensive overestimation or underestimation of torsional response of the inclined tower legs.
Experimental and numerical study on seismic response of inclined tower legs of cable-stayed bridges during earthquakes
https://orcid.org/0000-0001-8341-5903
Highlights A scaled bridge model was tested to study seismic response of inclined tower legs. A numerical model with multi-linear torsional stiffness was established. Bending and torsion together caused the damage of inclined tower legs. An elastic stiffness of torsion led to inaccurate torsional response.
Abstract More than half of cable-stayed bridges adopt the tower with inclined legs, which can be loaded with a combination of bending, torsion, shear and axial force under earthquakes. To study the seismic response of inclined tower legs, shake table tests were conducted on a 1/20 scaled cable-stayed bridge model with an inverted Y-shaped tower. A description of the model design was introduced and observed damages including horizontal and diagonal cracks at inclined tower legs were presented. A numerical model, considering reduction of torsional stiffness of inclined tower legs after diagonal cracking, was established. The feasibility of the numerical model was validated by a comparison of numerical and test results, which showed good correlation in displacement response at tower top and deck end, and cable force. Based on numerical results, the crack torsional moment of the inclined tower could be easily reached at small peak ground acceleration (PGA), leading to a substantial reduction of torsional stiffness of the section. This reduction helped alleviate the torsional moment demand at larger PGAs and delay the torsional failure of the tower legs. Numerical results also revealed that the bending moment is the primary factor to cause concrete cracks at the lower regions of inclined tower legs whereas complex interaction of large bending moment and torsion results in flexural and torsional damage near the intersection. Conventional ways, which adopt an elastic behavior of torsion, either using stiffness prior to or after diagonal cracking, will lead to intensive overestimation or underestimation of torsional response of the inclined tower legs.
Experimental and numerical study on seismic response of inclined tower legs of cable-stayed bridges during earthquakes
https://orcid.org/0000-0001-8341-5903
Highlights A scaled bridge model was tested to study seismic response of inclined tower legs. A numerical model with multi-linear torsional stiffness was established. Bending and torsion together caused the damage of inclined tower legs. An elastic stiffness of torsion led to inaccurate torsional response.
Abstract More than half of cable-stayed bridges adopt the tower with inclined legs, which can be loaded with a combination of bending, torsion, shear and axial force under earthquakes. To study the seismic response of inclined tower legs, shake table tests were conducted on a 1/20 scaled cable-stayed bridge model with an inverted Y-shaped tower. A description of the model design was introduced and observed damages including horizontal and diagonal cracks at inclined tower legs were presented. A numerical model, considering reduction of torsional stiffness of inclined tower legs after diagonal cracking, was established. The feasibility of the numerical model was validated by a comparison of numerical and test results, which showed good correlation in displacement response at tower top and deck end, and cable force. Based on numerical results, the crack torsional moment of the inclined tower could be easily reached at small peak ground acceleration (PGA), leading to a substantial reduction of torsional stiffness of the section. This reduction helped alleviate the torsional moment demand at larger PGAs and delay the torsional failure of the tower legs. Numerical results also revealed that the bending moment is the primary factor to cause concrete cracks at the lower regions of inclined tower legs whereas complex interaction of large bending moment and torsion results in flexural and torsional damage near the intersection. Conventional ways, which adopt an elastic behavior of torsion, either using stiffness prior to or after diagonal cracking, will lead to intensive overestimation or underestimation of torsional response of the inclined tower legs.
Experimental and numerical study on seismic response of inclined tower legs of cable-stayed bridges during earthquakes
Yi, Jiang (Autor:in) / Li, Jianzhong (Autor:in)
Engineering Structures ; 183 ; 180-194
27.12.2018
15 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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