Analysis On The Effect Of Damage Defects On Stress Of Mine Headframe

Mine headframe during installation and service,Due to long-term exposure to sun and rain,frequent lifting loads,installation errors,atmospheric corrosion and coating construction processes are not standardized.Will produce various damage defects,making it difficult to meet the design load requirements.In recent years,the research on the vulnerability of headframe is gradually carried out,but the research on the damage of headframe damage mostly stays under a single defect.The research on the safety of headframe under the joint action of various damage defects is not comprehensive enough.In this paper,the safety of the headframe structure is evaluated by finite element simulation analysis by studying the headframe within the reasonable damage range,provide a scientific and effective assessment method for the safety of in-service headframe structures with damage defects,provide some reference conclusions for the design and maintenance of mine headframe.(1)Within the reasonable damage range,local corrosion,local bending and local composite defects of key rod and guideframe have little effect on the overall stress and displacement of the headframe.The maximum stress and maximum horizontal displacement of the headframe structure are compared with those without defects.Increased by 2.5%and 4.9%,which has a greater impact on the stress of the damaged member.(2)Within the reasonable settlement range,the support settlement has little influence on the overall stress of the headframe structure and has a great influence on the horizontal displacement.The support settlement changes the stress system of the original headframe and the over-collapse is easy to cause overturning.During the headframe construction and installation process,attention should be paid to the treatment of the foundation.In the composite defect of local damage and support settlement of key rod,the maximum stress of the headframe structure decreased by 4.2%compared with the defect-free,and the maximum horizontal displacement increased by 9.2%.(3)The overall moderate tilt has little impact on the safety of the headframe.The overall corrosion damage and the maximum horizontal displacement of the headframe structure increase by 52.5%and 54.6%.(4)Overall corrosion,overall inclination,support settlement and local damage defects are combined,The maximum stress and maximum horizontal displacement of the headframe structure are up to 44.1%and 63.1%compared to the defect-free headframe structure.(5)The first-order frequency of the headframe without damage defect is 1.7930,the first-order frequency of the damage defect is 1.4528,and the first-order frequency of the damage defect with support settlement is 1.4523;the damage defect causes the headframe frequency to decrease and the lateral stiffness to decrease;the support settlement further reduces the frequency of the damage headframe,but the reduction is very small.(6)The results of time history analysis show that the maximum interlayer displacement angle of the headframe without damage defect is 1/1176,and the maximum stress of the headframe is 50.7Mpa;the maximum interlayer displacement angle of the headframe with damage defect is 1/813,and the maximum stress is 90.4Mpa;the damage defect has little influence on displacement and has great influence on stress.Figure[55]table[7]reference[58]...