The Analysis Of Rockfall Decrease The Bearing Capacity Of Angle Steel Members Of Transmission Tower

The transmission tower structure is an important support structure in the transmission line,and the stability design of its components is an extremely important work.Relevant design specifications have been formed for the stability of the components of the transmission tower during normal service.However,the research on transmission tower structure in areas where rockfall hazards exist and the bearing capacity of its components is impaired by rockfall is not yet fully researched.Therefore,this paper takes the key angle steel members of typical tensile tower structures in transmission lines as the research object,Analysis of the deformation response of the weak point of the angle steel under different impact energies and the reduction of the load capacity of the angle steel after the impact is damaged,And establish the relationship curve between deformation and residual bearing capacity and damage factor,The maintenance work of the transmission tower during normal service period can be used for reference and reference for related research.This paper analyzes the problem of bearing capacity loss of key angle steel members of transmission tower under different rockfall impact energy through numerical simulation.First of all,the survey selected the typical tension tower with the number7830 and its two key components in the transmission lines in the southwest region.Then establish a finite element model of the component,and simulate the impact of the key component by changing the impact position and impact angle of the falling rock to obtain the weak part of the angle steel.Finally,the nonlinear buckling analysis is used to study the residual load-bearing capacity and damage degree of the angle steel under different rockfall impact energies.The change law of the angle steel's residual load-bearing capacity and damage degree with the deformation of the impact point of the angle steel is analyzed and discussed,and the impact point deformation is evaluated for damage,Propose related repair and reinforcement measures.The main conclusions obtained from the research of this thesis are as follows: The deformation value of the impact point obtained by numerical simulation analysis is consistent with the measured data,and its finite element model is feasible;For the key member of the typical 7830 tensile tower structure,the weak position of the main angle member is located on the flange of the angle steel,and when the angle steel undergoes significant plastic deformation,the deformation of the angle steel increases slowly with the increase of the impact energy.The weak part of the angle steel angle member is at the angle steel corrugated line,and when the angle steel undergoes significant plastic deformation,the deformation of the angle steel increases rapidly with the increase of the impact energy;The main material angle steel member is torsional buckling when it becomes unstable.When the deformation value reaches 0.013 times the length of the angle steel,the transmission tower angle steel member is seriously damaged.It is recommended to strengthen and repair in time.When the deformation value reaches0.037 times the length of the angle steel,the transmission tower member is completely destroyed and loaded If the capacity is lost,it is recommended to dismantle and replace it in time;The inclined steel angle member is buckling when it is unstable.When the deformation value reaches 0.0057 times the length of the angle steel,the transmission tower member is severely damaged.It is recommended to strengthen and repair in time.When the deformation value reaches 0.02 times the length of the angle steel,the transmission tower member is completely destroyed and the bearing capacity is lost,It is recommended to dismantle and replace in time.