Assessment results of soil properties by engineering-geophysical studies

Abstract

Relevance. The article presents the results of engineering-geophysical studies on the territory of the new compressor station of the Special Underground Gas Storage (SPGS) in the city of Abovyan (Armenia). Considering that the Republic of Armenia is located in a seismically active zone, these studies are highly relevant, and the new compressor station of the Special Underground Gas Storage is especially important object. The Aim of the presented work is to identify the features of the specific electrical resistivity of soils, the presence of stray currents, assess the corrosive aggressiveness of soils, seismic conditions of the territory and the expected seismic intensity in the area designated for construction. Methods. The determination of the specific (apparent) electrical resistivity of the soils of the study area was carried out by the method of electrical profiling using symmetrical four-electrode Wenner setup. The article presents the points of measuring the electrical resistivity of soils in the territory of the new compressor station of the Abovyan SPGS, revealed the presence of stray currents, tables of the degree of corrosiveness of soils are given, the locations of the presence of a dangerous level of stray currents are indicated. Also works on seismic microzoning were carried out, the values of the expected seismic intensity of the compressor station territory were determined. The expected seismic intensity in this area has been determined based on analysis of engineering-geological materials, taking into account the results of field engineering-seismometric instrumental studies. By using shallow seismic surveys have determined the speed of seismic velocity. Measurements were carried out horizontally oriented seismic receiver SM-3 (vertical impact). Shock waves were generated by pulsed excitation. To provide the required excitation power the impulse action was created using a falling weight. Results. The article presents the seismic conditions of the territory, the results of seismometric studies, data on observations of microseisms, Fourier spectra of prevailing periods for some observation points, a scheme of engineering seismometric observations. As a result of the research carried out, it was found that that the soil conditions composing this territory belong to the soils of the first category in terms of seismic properties, the expected seismic hazard of the investigated area should be taken as I = 7 points or PGA = 0.24 g.