Dynamic response of column bases

In this paper, the dynamic behaviour of a column base connection simulated by a cantilever on elastic supports is studied. The model considered consists of the column with length ℓ, moment of inertia I and mass m per meter, with a concentrated mass M and rotational inertia J in its tip. In the bottom of the column the connection with the concrete foundation is obtained using two springs, one rotational and one translational. Through these two springs the behaviour of this connection is realised taking into account the influence of various parameters (i.e. base-plate, anchor bolts, material properties etc.). The equation of motion of the system is established and the shape functions of the model considered are obtained. The external excitation is a dynamic ground motion having a general equation form (with the possibility to change the parameters that affect this function), also taking into account the damping of the system. On the basis of the equations derived, the influence of the various parameters that are inserted in the problem is examined, and some of the results are presented in tabular and graphical form, giving useful deductions for further research.