Assessment on the stress state and the maintenance schemes of the transmission tower above goaf of coal mine

FEA model of a transmission tower was established. According to the monitoring data of the non-uniform settlement for the temporarily strengthened tower, the bearing capacity analyses were carried out with the wind loads of different velocities and directions. When the wind velocity is up to the design value, the stress of the main member exceeds the design stress by 34%. For the frequent velocity, stresses of all the members are lower than the design stress. By considering the settlements at the four foots are stochastic, one single installing program of the staying wires cannot decrease the stress of the members for all cases. For the settlement case which the member stress is up to the maximum value, the member stress decreases a little but even higher than the design value. By applying the large panel foundation, the bearing capacity of the tower can be enhanced significantly, and the settlement limit was determined by the structural analysis.