Calculation of the Rotational Stiffness and Moment Capacity of Pinned Column Baseplate Connections [N17]

Past studies have indicated that base connections, which are designed as pinned supports (anchor rods are placed inside column flanges), exhibit a non-negligible level of rotational stiffness. Neglecting the rotational stiffness of the base connection may result in a significant overestimation of the story drift. This additional story drift is addressed by increasing the flexural stiffness of the frame members thereby unnecessarily increasing the cost of the building. The current AISC and AISC Design Guide 1 provisions do not provide design guidelines and experimental data to support the use of rotational stiffness and moment capacity of the so-called pinned column base-plate connections. To bridge this gap, this study has evaluated the rotational stiffness and moment capacity of different pinned column base-plate connections. This presentation will focus on methods to predict the moment capacity of the pinned column base-plate connections based on AISC code equations. In parallel, the comparison between the results of the computed moment capacity and the moment capacity measured during the experiments of this research program will be presented. Last, due to limitied design procedures in the current AISC provisions to estimate the base-plate rotational stiffness, Eurocode design procedures have been employed to compute this quantity. This presentation will conclude with a comparison of the measured rotational stiffness and the computed rotational stiffness based on Eurocode. The results presented are considered as a thorough evaluation of the exiting design practices for pinned column base-plate connections.

Intended Audience: Engineers
Track: Design & Analysis

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