Research On Dynamic Performance Of PC Composite Box Girder Bridge With Corrugated Steel Webs

Since it was invented in the 1980s, due to many advantages, the prestressed concrete composite bridge with corrugated steel webs has been favored by engineers of many states. Later, this composite bridge structure has witnessed a rapid development around the world with the static mechanical properties of the structure have been systematically researched. Comparatively speaking, the dynamic performances of the composite bridge were few studied, especially in aspects of dynamic performances and vibration isolation performances under seismic excitation. In order to deeply understand the dynamic performances of the prestressed concrete composite bridge with corrugated steel webs, combining with the methods of theoretical analysis, experimental study and numerical simulation, this paper does research on the aspects of dynamics perperties, dynamic performances and vibration isolation performances of the structure under seismic excitation. The mainly accomplished work is listed as follows:The effects of external prestressing, shear lag and shear deformation, shear deformation are analysed, and the computational formulas of bending and torsional vibration frequency for the prestressed concrete composite box-girder with corrugated steel webs are deduced. Through the dynamic property experiment of the prestressed concrete composite box-girder with corrugated steel webs, applicability of the above-mentioned theoretical formulas are verified, and the effects of relevant factors on vibration frequency are analysed.Through adjustment of corrugated steel webs changing parameters(steel web thickness, slant angle, corrugated angle, the type), the effects of accordion effect on the dynamic properties of the prestressed concrete composite box-girder with corrugated steel webs are researched.The concept of relative frequency ratio is proposed to quantitatively analyse the effect of accordion effect on dynamic properties of composite box-girder with corrugated steel webs. The effects of various factors of corrugated steel webs(steel web thickness, slant angle, corrugated angle, the type) on relative frequency ratio of the prestressed concrete composite box-girder with corrugated steel webs are analysed, and the effects of depth-span ratio on each order vibration mode of the prestressed concrete composite box-girder with corrugated steel webs are researched.The dynamic computational model of prestressed concrete composite bridge with corrugated steel webs is established, and the effects of various factors(spectral characteristics of ground motion, damping ratio, pier altitude difference, vertical ground motion, sliding friction coefficient) on seismic response for prestressed concrete composite bridge with corrugated steel webs(continuous rigid frame bridge and continuous beam bridge) is analysed. The effects of traveling wave effect and pile-soil interaction on seismic response for prestressed concrete composite bridge with corrugated steel webs(continuous rigid frame bridge and continuous beam bridge) are researched.The application of multi-scale model in composite box-girder with corrugated steel webs is studied. The multi-scale model of prestressed concrete continuous rigid frame bridge with corrugated steel webs is established. The above model takes into account the material plastic damage, and the seismic performance of key parts for prestressed concrete continuous rigid frame bridge with corrugated steel webs is studied. The effects of lining concrete length and accordion effect on the seismic performance of key parts for prestressed concrete continuous rigid frame bridge with corrugated steel webs are analysed.The semi-active control system is introduced into prestressed concrete continuous beam bridge with corrugated steel webs, and the seismic response reduction of it is researched. The effects of ground motion spectral characteristics and traveling wave effect on the seismic response reduction of semi-active control system for the prestressed concrete continuous girder bridge with corrugated steel webs are analysed.