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One of the most used instrumental measurements for earthquake intensity is maximum ground acceleration at. Earthquake load does not act directly on the structure in the form of force, as other loads, but indirectly, via ground motion. Mass acceleration in case of infinitely rigid structures is equal to ground acceleration, so for such structures, the maximum inertial force on the structure is equal to the product of mass and maximum ground acceleration. For this reason, in case of rigid structures, it has a consistent correlation with the damage on the structures. In the paper, except for the maximum ground acceleration, also analyzed are the maximum ground displacement, the maximum ground velocity, duration of the intensive part of oscillations and frequency composition of oscillations (predominant periods). Considerations of certain characteristic ground oscillations are best accomplished by comparison of accelerograms of the earthquakes which occurred. Maximum velocity decreases with the decrease of magnitude and distance from hypocenter. Maximum ground displacements are important primarily for flexible structures. For corresponding impacts are given characteristic formulas and characteristic tables and diagrams, better explaining the subject matter. [ABSTRACT FROM AUTHOR]

Seismic effects that occur during mining in open pits are similar to the seismic effects of small and medium intensity earthquake. The paper outlines how the enormous energy is released during a strong earthquake and regardless of the hypocenter depth that could be dozens of kilometers, the area affected by a strong earthquake is very large and the intensity is very high. Notwithstanding the much lower energy released during mining, there is a seismic damage to buildings in the surroundings, as pits are usually near residential areas. A complex solution of the problems of mining and seismic effects can be reached only by experimental investigation. Earthquake can not be controlled, but the mining can be directed in full, especially by adequate amount of explosive charge and direction of mining. So this fact must be taken into account and proposed formulas are based on these conditions. A special note is given to the seismic anomaly that buildings closer to the field of mining are in some cases less affected than more distant ones. Therefore the new non-standard formulas will be given in the paper, which are more adequate for solving this seismic anomaly. The influence of blasting location with two boreholes charged, one with the initial explosive at the top and the second in the bottom of the drill, is analyzed. This approach significantly contributed to solving some anomalies, such as that much of the wave's energy is released in the area far away from the mine. Hence there is a need for better protection from seismic effects on buildings at these locations. [ABSTRACT FROM AUTHOR]