Study On Mechanical Properties Of Continuous Rigid Frame Bridge Considering The Local Deviation Of Bridge Pier

Since the reform and opening up,China's highway bridge construction has been booming,many bridges have mushroomed,especially the continuous rigid frame bridge with its unique advantages,in the actual project has been widely used.Many scholars have achieved more gratifying achievements in the stress,earthquake and stability of continuous rigid frame bridge.However,due to the ever-changing actual engineering,there are still many problems to be solved in reality.At present,there are still few studies on the problem of force,earthquake and stability of continuous rigid frame bridge with initial defects considering bridge pier.In this paper,a continuous rigid frame bridge with initial defects of bridge Pier in southwest region is the engineering background,the mechanical properties of the continuous rigid frame bridge with initial defects of the pier are studied from the static characteristics,dynamic characteristics and stability characteristics of the structure.The work and the main conclusions of this paper are as follows:1?Through the construction site on the pier of the initial understanding of the situation,to explain and simplify the simulation,and then put forward targeted to increase the cross-section,the additional beam of two kinds of disposal methods.2?For the continuous rigid frame bridge with local deviation of the pier,the static characteristic analysis is carried out by using MIDAS / civil software without taking any disposal measures.The results show that: The bridge structure is safe during the whole construction and operation,and the structural stress and displacement are within the controllable range and meet the specification requirements.In addition,compared with the static results and continuous rigid frame bridge without initial defects of the pier,in addition to the bridge pier at the shear force and bending moment,the rest of the pier force did not change significantly on the superstructure has no significant impact.3?In order to solve the problem of the initial defects of the pier,the seismic response spectrum analysis and the elastic time history analysis of the structure are carried out,and the calculation results of the two analytical methods are compared.The results show that: Whether in response spectrum analysis or time history analysis,the main beam across the middle of the pier beam and the end of the internal force larger.In addition,compared with the results of seismic response and continuous rigid frame bridge without initial defects of the pier,in addition to the increase in axial force at the cross section of the 2 # pier,the internal forces at the control cross section of the rest of the piers and the main girder did not change;the longitudinal displacement curves of the piers were abruptly changed,but the amplitude of the mutation was very small.4?In order to solve the problem of the initial defects of the pier,the linear elastic stability of the structures under the maximum cantilever condition is obtained from the increasing cross section method and the additional beam method.The results show that: The stability factor of the bridge structure is improved after the above two treatment methods.5 ? Based on the number,position and stiffness of the beam,the dynamic characteristics and seismic performance of continuous rigid frame bridge with initial defects of the pier are analyzed.The results show that: The internal force of seismic analysis and the internal force of seismic analysis are also different.Compared with the position and stiffness of the beam,the seismic response is greatly influenced by the number of beams.The research contents of this paper will provide an important theoretical guarantee for the repair of a continuous rigid frame bridge with Local deviation of the pier,and provide a reference for the study of similar bridges.