The solution of a single-storey industrial building, of working with significant horizontal seismic vibrations. Earthquake building carried out by separating the sole-plate foundation resting on the ground, from the rest of the multi-stage foundation for the frame column. The gap formed by constructive in the individual cells are arranged point-balls bearings, have freedom of movement in the horizontal plane. Under horizontal vibrations of the earth and the sole-plate the rest of the basement and the building itself remain at rest. It noted an interesting fact: the performance and reliability of the proposed solutions of seismic stability of buildings received unexpected confirmation,  that one of the buildings in the Chilean capital of Santiago, built in the sixteenth century, survived dozens of earthquakes, is the oldest building and it became clear that its ancient walls are mounted on ball-shaped stones.

The article examines the application of new design systems in seismic areas and the suitability of seismic standards for their design.

 

A calculation method for structures under seismic impacts is proposed taking into account changes in buildings' structural design during deformation, based on the normal forms
method and the presentation of design forms for calculating seismic forces in the form of expansions in the forms of natural vibrations. These formulas are close to the calculated ones given in a number of standard documents. The solution is made in time steps. At each step, the structural design is adopted from the results of the static calculation for seismic forces determined at the previous stage. The solution method is getting built in the form of forms expansions using the software MATHCAD. The seismic forces numerical values are
calculated at each time step, taking into account changes in the structural design in the previous step by static calculation for seismic forces impacts. The proposed approach allows us to evaluate the seismic forces values, taking into account changes in the structural design during oscillations at each time step. A change in the structural design is evaluated by static calculation based on seismic forces determined in the previous step. The coefficient K1 values were estimated as the ratio of seismic forces at the stage preceding
failure to seismic forces at the stage corresponding to the end of the elastic stage.

The author derives the equation of motion for a structure resting on kinematical pendulum supports of Yu.D.Cherepinsky. Both structure and supports are assumed to be rigid; no
sliding is assumed during rolling. Two components of seismic excitation are considered (horizontal one and vertical one). Equation of motion for free vibrations looks like that of the free vibrations for massive pendulum support standing alone (it was studied earlier). It is fact the equation of motion for pendulum, but center of rotation, inertia moment and stiffness are varying with time. This equation may be simplified to the linear one by skipping the second
order terms. The equation of motion for seismic response after linearization is the extension of the Mathieu-Hill’s equation, where horizontal component is responsible for the right-hand part (in the conventional Mathieu-Hill’s equation it is zero), and vertical component creates parametric excitation in the left-hand part. In fact, vertical seismic acceleration modifies gravity acceleration g, which controls the effective natural frequency for pendulum.
Thus, there might appear dynamic instability (though without infinite response due to the finite duration of excitation). The author presents numerical example.