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 consis ts of the column with length l, moment of inertia I and mass m per meter, w ith a concentrated mass M and rotational inertia J in its tip. In the botto m of the column the connection with the concrete foundation is obtained usi ng two springs, one rotational and one translational. Through these two spr ings the behaviour of this connection is realised taking into account the i nfluence of various parameters (i.e. base-plate, anchor bolts, material pro perties etc.). The equation of motion of the system is established and the shape functions of the model considered are obtained. The external excitati on is a dynamic ground motion having a general equation form (with the poss ibility to change the parameters that affect this function), also taking in to 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. (C) 2000 Elsevier Sci ence Ltd and Civil-Comp Ltd. All rights reserved.