Purpose: To show the features of the calculation of constructions in opposition to the effect of weak frequent earthquakes. Methods: Numerical modeling of seismic vibrations of constructions. Analysis of limit states. Results: The specificities of construction calculation for impact of weak earthquakes are analyzed. Earthquakes of 1 per 30 and per 50 years repeatability are considered. In the first case, after an earthquake a construction should operate standardly, without damage. In the second case, damages, that does not affect construction exploitation, are accepted. Main attention is paid on the three issues: setting of elastic and damping characteristics of ferroconcrete, formalization of limit states, load combinations. The dependence of a damping from ferroconcrete reinforcement degree is estimated. When evaluating limit states, besides calculations on crack resistance and strength, the possibility to exclude people panic is considered. To make so, it’s proposed to limit speed level in certain octave ranges. Proposals are developed for estimation of coefficients for combinations of various loads with seismic ones. The coefficients for combinations of seismic and ice loads are evaluated. Practical importance: A system of calculating coefficients has been established to assess seismic resistance under relatively weak, frequent impacts. It’s been shown that for strong impacts, the combination coefficients for different regions turn out to be close to each other, while for weak impacts, they can differ drastically.