Three dimensional elastic dynamic analysis of a 985 foot high freestanding communications tower

Abstract

This paper reviews the design development of a 985' high free-standing communications tower recently constructed in San Francisco. Included is a description of the structural configuration of the
 tower and the criteria by which it was designed. The dynamic characteristics of a three-dimensional linear elastic mathematical computer model, devised to represent the physical structure, are presented. The dynamic response of this computer model to various levels of
ground shaking, including both horizontal and vertical excitations,
 are summarized, evaluated and compared to the seismic force levels prescribed by the 1969 edition of the San Francisco Building Code.
 Also included in the comparison are the responses derived for the tower from wind tunnel studies and static wind design criteria.