Обеспечение сейсмической безопасности строительных объектов при массовых промышленных взрывах с учетом предельных состояний первой группы

Abstract

In certain situations, seismic safety during open-pit mine blasts can be ensured only on the condition of coordination of the explosion technology regulatory documents with the provisions of the construction field regulatory documents. The distinctive feature of the construction documents is the application of probabilistic approaches to load specification. The limit state method is used to calculate the structures. The probability of non-exceeding the design values of the main loads is adopted as not less than 0.98 for the calculations of the first group of limit states. The explosion technology regulatory documents take into account the second group limit states at which the operation of protected objects is possible but hampered, for example, as a result of the increased frequency of objects’ repairs. At the same time, the probability of minor damages is 0.9–0.95. The methodology to ensure the seismic safety of protected objects during open-pit mine blasts, based on regression analysis of the experimental data and considering the probabilistic nature of such effects, is presented. The methodology considers all features of explosion technology applied at a given enterprise, as well as the structure of the geological environment along the way of seismic wave propagation, and other factors. Despite many advantages, however, the probabilistic approaches limit the minimum number of experimental points required to build a regression line and the limits of confidence intervals. Therefore, the increase in the confidence level of peak particle velocity from 0.95 to 0.98 must be accompanied by the increase in the minimum number of experimental points used to build the regression from 80 to 200, which significantly increases the scope and cost of the required experimental studies. The article considers the possibility of an increase in the confidence level of peak particle velocity caused by open-pit mine blasts from 0.95 to 0.98 without increasing the volume of the experimental sample; the conditions under which it becomes possible are analyzed as well.