Effect Analysis Of Two-way Curved Arch Bridge Strengthened By Fill Core Method And Study Of Secondary Load Effect

The deficiency of transverse stiffness is the main defect of two-way curved arch bridge,which leads to a large number of two-way curved arch bridge were damaged by beam diseases,which seriously reduces its transverse mechanical properties.Many two-way curved arch bridge could not meet the requirements of modern traffic.However,considering the economical and the unique cultural value of two-way curved arch bridge,it is urgent to strengthen the damaged two-way curved arch bridge in order to meet the normal service requirements.In this paper,aiming at the defect of insufficient transverse stiffness of two-way curved arch bridge,the influence of beam damage on transverse mechanical properties of two-way curved arch bridge was analyzed by taking the transverse load distribution coefficient as judgment index.At the same time,the reinforcement effect of fill core reinforcement method and its secondary load effect were studied.The main work of this paper is as follows:(1)Analysis of calculation method for load transverse distribution coefficient of two-way curved arch bridge.This paper was based on the approximate calculation of transverse load distribution of non-slab arch bridge proposed by Li Guohao.Firstly,the transverse load distribution coefficient of two-way curved arch bridge was calculated by using the calculation method of beam bridge with enhancement coefficient.Secondly,compared the calculation results with finite element method,and obtained the most suitable method for calculating the transverse load distribution coefficient of two-way curved arch bridge.In this paper,it is considered that the rigid plate method with enhancement coefficient is the most suitable for calculating the transverse load distribution coefficient of two-way curved arch bridge.(2)Analysis of the influence of beam damage on transverse mechanical properties of two-way curved arch bridge.The influence of different damaged position and degree on the influence line and load transverse distribution coefficient of two-way curved arch bridge was studied by changing the position and degree of damage.In this paper,it is considered that beam damage has the greatest influence on the arch rib of both sides of the damage,from the damage position to the unaffected point,the damage gradually decreases to zero,and from the unaffected point to the farthest end,the influence increases gradually,and the more serious the beam damage,the more obvious the law is.(3)Analysis of the influence of fill core reinforcement method on transverse mechanical properties and carry capacity of two-way curved arch bridge.Established the finite element model by ABAQUS software,analyzed the influence of fill core reinforcement method on transverse mechanical properties of two-way curved arch bridge;And established the model ofthe main arch rib by ANSYS software,analyzed the influence of fill core reinforcement method on the carry capacity.In this paper,it is considered that fill core reinforcement method can greatly improve the transverse mechanical properties of two-way curved arch bridge,and greatly improve the carry capacity of arch rib.(4)Theoretical analysis and formula derivation of carry capacity of two-way curved arch bridge strengthened by fill core reinforcement method.Firstly,discussed the failure forms of arch ribs after reinforcement,and analyzed the mechanical characteristics of various failure forms.Then,on the basis of following the hypothetical conditions,combined with the mechanical characteristics of various failure forms,derived the formulas for calculating the carry capacity of various failure forms.(5)Finite element analysis of secondary load effect.Using the birth and death element method of ANSYS software,established the arch rib model with secondary load effect.analyzed the influence of initial load on reinforcement effect.In this paper,it is considered that the initial load of the structure will accelerate the rate of displacement change,and cause the steel bar to reach the yield state prematurely,but the initial load has little effect on the ultimate carry capacity of the structure.