ПРЕДВАРИТЕЛЬНАЯ ОЦЕНКА ПРОЯВЛЕНИЙ ПРОГНОЗНОЙ СЕЙСМИЧНОСТИ НА УЧАСТКЕ МАТЕРИК–САХАЛИН ДЛЯ КРИТИЧЕСКИ ВАЖНОГО ЛИНЕЙНОГО СООРУЖЕНИЯ

Abstract

The article presents the findings of seismic hazard zoning of the submerged crossing of the pipeline in the Nevelskoy Strait, between the village Lazarev of the Nikolaevsky district, Khabarovsky Krai, and the Cape Pogibi near the Pogibi village, Sakhalin Oblast. Along the water area, this section of the submerged crossing is limited by the zone which is 500 m wide by 11 km long. It follows from the stock of geological documents of the Geophysical Service of the Russian Academy of Sciences and the OSP-2015 map that the highest seismic activity in the Okhotsk region is observed in the area of the Kuril Islands, and the central seismically prone zone of northern Sakhalin is closest to the construction site. Large earthquakes are recorded by a number of seismological stations in the immediate vicinity of the construction site. The foci of nearby earthquakes occur east of the construction site and are mostly confined to the systems of deep faults resulting from the juncture between the West Sakhalin synclinorium and the Sikhote-Alin volcanic belt. The main purpose of the research is related to the development of a methodology for prognosticating seismic effects for the strong earthquake prone areas. In this context, an approach is proposed for the specific structure, which is based on the construction of a set of seismic models to reach the reference bedrock, setting of the pickup signal corresponding to the initial seismicity of the area, calculating the main parameters of seismic effects for them, and then, in a first approximation, the implementation of the technology for constructing engineering-seismological cross-section along the pipeline construction site. The proposed approaches to prognosticating seismic events for that part of the pipeline submerged crossing in the Nevelskoy Strait are based on certain constraints that made it possible to obtain a set of parameters of seismic effects for prognosticated strong earthquakes necessary for designing and constructing an earthquake-resistant linear structure. Given improved calculation methods and critical object monitoring, the advantage of this approach is the ability to recalculate seismic effects to the structure using the constructed seismic ground motion models.