Improvement of Seismic-Proof-Ability Concerned with the Power Pole System

This paper deals with the subject closely related to the dynamic behavior of the distribution power pole. In 1995 at Kobe we had encountered with the great earthquake, and about 11,300 power poles were damaged with this earthquake. This disaster awakened us to the necessity of studying dynamic characteristics of the power pole system caused by the movement of the ground due to earthquake. Only few attempts have so far been made at this subject. We have set up a real power pole on the vibration-test-machine, which can move within the one-dimensional (x) horizontal plane. The experimental results show that the oscillation of a pole is not restricted within one-dimensional (x) space but move within the two-dimensional (x-y) horizontal space. With this result, we can say that the mechanical model, which describes the dynamic behavior of a power pole, is much more complicated than the simple inverted pendulum. We succeeded to establish a circuit diagram, which can represent the same oscillation phenomenon that is obtained by the experiment. With using the results of circuit simulation, our experimental study by the vibration machine can be complemented. In the latter half of this paper, various knowledge obtained by the experiments are described