Nonlinear dynamic analysis of an industrial chimney's pile foundation system for hurricane loading

This paper presents the results of a nonlinear dynamic analysis to evaluate the structural performance of a pile and mat foundation system supporting a 350 feet tall concrete chimney stack for hurricane force wind loads. Wind tunnel testing was conducted to develop wind load time histories along the height of the chimney. A geotechnical investigation was performed to determine the nonlinear characteristics of the pile behavior under lateral and vertical loads. A global nonlinear computer model of the chimney and foundation system was developed to determine the performance of the chimney's foundation under the wind load time histories. The concrete windshield, pile cap and individual piles were modeled in the computer simulation. Two levels of wind speed were considered (a) a 157 mph wind speed (3-second gust, at a height of 10 m in Exposure C, 150-year return period) and (b) a 225 mph wind speed (3-second gust, at a height of 10 m in Exposure C, 10,000-year return period), for the analysis. Results of nonlineardynamic time history analysis are presented in this paper.