| Beam-T continuous rigid-frame bridge has the advantage of convenient in construction and lower cost, adapt to the characteristic of viaduct in mountain area. It is widely used in expressway in mountain area. The ratio of beam bending rigidity to pier lateral displacement rigidity is a critical parameter for the mechanical performance , this paper compare variable parameters such as span, height of pier, thickness of pier and the style of pier by the finite element method base on building reference model, in term of seismic internal force and influence on different soil profile type. The basic conclusions are drawn: (1) The same model placed on site II and site III, when the frequent earthquake ground motion is inputted in X direction(longitudinal direction of the bridge),the seismic internal forces of site II is larger than site III by 0.8 percent, when inputted in Y direction(transversal direction of the bridge),it is larger than site III by 3.4 percent; when the rare earthquake ground motion ,they are the same. (2) Span is an important parameter for seismic response of beam-T continuous rigid-frame bridge. When the earthquake ground motion is inputted in X direction(longitudinal direction of the bridge),the seismic internal forces decrease with the increase of the span. When the earthquake ground motion is inputted in Y direction(transversal direction of the bridge),the seismic internal forces increase gradually with the increase of the span. (3) The height of pier is an important parameter for seismic response of beam-T continuous rigid-frame bridge. When the frequent earthquake ground motion is inputted in X direction(longitudinal direction of the bridge),the seismic internal forces decrease with the increase of the height of pier; when the earthquake ground motion is inputted in Y direction(transversal direction of the bridge),the moment of pier increase firstly and then decrease with the increase of the height of pier, shear remain the same, axial force increase rapidly. The rule is the same with the rare seismic level. (4) Thickness of pier is also an important parameter. When the earthquake ground motion is inputted in X direction(longitudinal direction of the bridge),the seismic internal forces increase with the increase of the thickness of pier. When the earthquake ground motion is inputted in Y direction(transversal direction of the bridge),the seismic internal forces increase rapidly with the increase of the thickness of pier. (5) The style of pier is another important parameter. When the frequent earthquake ground motion is inputted in X direction(longitudinal direction of the bridge),while the area of pier doesn't change and the length of pier in longitudinal direction of the bridge decrease, the seismic internal forces decrease rapidly; when the earthquake ground motion is inputted in Y direction(transversal direction of the bridge),the seismic internal forces increase gradually. The rule is the same with the rare seismic level. (6) The thickness of pier is the most sensitive to the natural vibration frequency of structure, then comes the height of pier, and then is the style of pier, span is the last. |
