Design of tower type structures to dynamic effects taking into account flexibility of the pile foundation and the base

Grounds and foundations, underground structures

The necessity to take into account flexibility of pile foundation in design of such structures as towers for mobile communication or radio equipment especially under dynamic loads (seismic, fluctuating component of wind load and the resonant vortex excitation) has been considered. The specific features of modeling of pile ductility, using program complex SCAD, were discussed and examples of corresponding calculations are given. The influence of pile parameters on internal forces and deflections of structure were also discussed. It was found, that for screw piles in the calculation results are mostly influenced by diameter of the broadening; the influence of trunk diameter of piles is considerably less. The effect of trunk pile diameter is much more important for piles without the broadening than for screw piles. It was also found that in most cases the effect of pile ductility in the vertical direction is much more significant than in horizontal.