Research on new wind-resistance strengthening method of power transmission tower by preventing main material buckling
Power transmission tower is high-rise and flexible structure,which is sensitive to wind loading.The bearing capacity,especially the compressive stability capacity of the steel angles used for main materials affects the wind-resistance performance of power transmission tower.To improve the anti-buckling capacity of the steel angles used for main materials under compressive loading,together with the consideration on decreasing the additional damage to the existing steel angle due to the hole-opening for the connecting bolts,a new strengthening method was proposed.Loading tests were conducted on six full-scale steel angle specimens to validate the strengthening effectiveness and examine factors that may affect the strengthening effectiveness.Finite element method analyze was also conducted simulating the loading tests to establish a reliable modeling method,which is essential for the strengthening design of the whole tower.It is revealed that the proposed new method can largely improve the bearing capacity,together with the ductility of the steel angles.Number of the bolts at the element ends for connecting the existing and installed angles remarkably affects the strengthening effectiveness.A reasonable value of the distance between the steel hose clamps was also proposed.Moreover,no clear effectiveness of stress lagging of the posted installed steel angle on strengthening effectiveness is observed.
power transmission towerhigh-rise flexible structuresteel anglehose clampcompression testforce transfer coefficientstrengtheningbearing capacity