| Summary: | Purposes Free standing columns are one of the typical features of traditional timber and stone buildings. Columns are the key components for transmitting vertical loads in traditional structures. Dead weight of the superstructure transmits to columns through the component at the top of the columns. The dynamic response characteristics of free standing columns subjected to horizontal earthquakes are analyzed in this research. Methods A two-dimensional rigid body model of a column was established on the basis of the structural characteristics and eccentricity of the component at the top of the column. The triggering critical conditions for different dynamic responses were deduced. The trigger sensitivity of the dynamic responses was explained according to the triggering critical conditions. Findings Results show that factors determining the type of dynamic response are static friction coefficient between the foundation and the bottom surface of the column, the slenderness ratio of the column, and the eccentricity of the component at the top of the column. There are three types of dynamic response that can be triggered on the column, including uplift, uplift and then slip, and simultaneous uplift-slip. Among them, uplift is the most likely to be triggered, and rocking after uplift is the main form of motion of timber columns. The triggering conditions of the column uplift can be affected by the slenderness ratio of the timber column and the eccentricity of the component at the top of the column, but the latter has a more significant effect. The geometric characteristics of the column, the mass of the column top member and its eccentricity have effects on the rocking motion of the column. This study provides the necessary theoretical basis for the state assessment and protection of ancient timber structures.
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