Метод анализа риска аварий на магистральных газопроводах в зонах активных тектонических разломов

Abstract

The considerable part of the Russian Federation’s territory is characterized by high seismic activity. More than 20% of the territory belongs to earthquake zones where earthquake shocks exceeding 7 on the Richter scale are possible, about 5% of the territory is vulnerable to seismic impact with intensity up to 8–9. Beside that the intensive development of mining industry and also hydroelectric development can lead to technogenic earthquakes. During strong earthquakes sometimes emerge faults (breaks) of land constituting essential danger to engineering constructions, in particular to the main pipelines in active tectonic fault zones, where soil displacements up to several meters are possible. In this work a method of failures risk assessment for main gas pipelines in zones with active tectonic faults has been presented. The method is based on correlation dependence of accident risk on the frequency of earthquake in the considered area and probability for exit of seismic fault to the surface during earthquakes of different intensity. The dependence of accident probability on a gas pipeline from the seismic event intensity has been proved. Accident frequency was defined with due regard to gas pipelines’ accidents intensity for the last 10 years, and frequency of earthquakes near constructions. Earthquakes incidence was accepted according to the maps for general seismic zoning OSR‑97. The need for fault existence accounting has been confirmed by statistical data’ calculation and analysis. The example for risk calculation on a main gas pipeline has been presented. The considered method can be used at the main pipelines design in seismically dangerous areas, and also for assessment the efficiency of actions for decreasing the risks indicators for extended linear objects in zones where these ones cross over active tectonic faults.