13th Conference and Exhibition Engineering Geophysics 2017

In the summer of 2015 geophysical surveys by GPR in the settlement area, located in the beam Berman (Sevastopol) have been carried out. Research task - identifying underground cavities along the southwestern slope of the beam. Field work was performed by georadar “OKO-2” with the antenna unit AB-250. At the initial stage it was carried out experimental and methodological work on the known cavities. According to the results of work it was identified the main features of voids. Then GPR works were carried out on a long reconnaissance profiles and small detailed areas. Analysis of radarograms showed that in the particular circumstances underground cavity characterized by reversed polarity of a signal reflected from the roof of the cavity, compared with the direct transmission signal. All radarograms clearly manifested only roof cavities, significant reflection from the “floor” is recorded only in the case of the known wide cave. Within the detailed site 1 identified and delineated underground cavity. All the other anomalies in the investigated area require further study. The survey revealed anomalies, presumably associated with unknown underground passages. These anomalies require further study.

This paper provides the results of geophysical investigation of burial mounds by means of electrical tomography and GPR. It is shown that electrical tomography allowed to determine the structure of research objects, to reveal and specify the burial place. The GPR method wasn’t efficient as expected due to clay structure of the soil in the most areas of Stavropol region. However its application allowed to obtain some specific information about objects.

The article describes the features of assessment of rock fracturing in engineering-geological study of chromite deposits Polar Urals. An algorithm for evaluating the extent and nature of the fracture, established patterns of change in the basic indicators of fracture, classifies species according to the degree of fracturing and engineering-geological zoning.

Despite the complexity of the relationship, and often care geology of problem solving methods of geophysics, it is necessary to find common ground, because geophysics is the oldest partner of engineering geology, it appeared in the temporary aspect of much earlier engineering geology. The report examines examples of solving geotechnical problems, which have not been solved without using of geophysical methods. At the same set of geophysical methods to the greatest extent focused on the use of the latest software and hardware tools professionally oriented geophysical companies - developers and producers (GEOSIGNAL, SIBGEOFIZPRIBOR, Geotech, etc.) And our own original designs, with international patents and scientific recognition (3D-3C seismic location underground and surface-based)

The group of companies CJSC “Aerogeophysical Surveys” and LLC “Sibgeotech” has developed principally new compact construction for continuous electromagnetic medium scanning in motion. This method is implemented for both electromagnetic scanning and continuous walking soundings with the depth up to 35 meters. The new technology has been widely approbated in different geological conditions (permafrost and thaw rocks of a various compositions) in winter and summer-autumn and has demonstrated high metrological characteristics.

Permafrost introduce significant complications in the industrial development of the territory, design and construction of various types of structures, geological and other studies. o date, one of the leading methods for studying the upper part of the section is a method for shallow Transient electromagnetic sounding (sTEM).

The results show high sensitivity sTEM signals the presence of MMPs in the upper part of the section for the near-surface geological conditions of Western Siberia.

The problems connected with the extension of the AMS-ZOND hardware-software package functional opportunities, the increasing of the informative and technological efficiency of results obtaining, have been considered. On the base of this package the stationary monitoring system technology has been developed, providing the opportunity to conduct the data recording and results interpretation in the automatic mode with the required value of the signal/noise ratio and get information about the physical condition of rocks laying in the depth interval from the surface to some hundreds meters.

The article presents the results of applying electrical resistivity tomography to study of active tectonic faults in southern Yakutia. To conduct the study we performed dipole-dipole array ABmn, two pole-dipole array Amn+mnB and reverse Schlumberger array mABn. In the case of Southern fault altered zone is clearly defined in the electrical survey data. In this case the direction of incidence and the geological features of the structure are clearly visible. In the case of Northern fault structure zones of altered rocks revealed not so clearly. Geoelectric boundaries are in good agreement with the data of seismic tomography.

Ice wedges are prominent phenomena of permafrost landscapes. These ice bodies typically build a characteristic polygonal micro topography, thus determining indirectly the distribution of moisture, vegetation, and elements within the seasonally unfrozen active layer. However, the existence of ice bodies in the subsurface is not always delineable based on surface data. Furthermore, the increased potential of subsidence poses a hazard to any infrastructure nearby in case of a temperature increase. Also, the identification of hidden ice bodies is relevant for scientific field work and drilling. Ground-penetrating radar has been proven to be a suitable geophysical tool for imaging sediments of the active layer at high resolution and determining the location of ice wedges in a non-invasive manner. However, the success of imaging based on widely used acquisition strategies (common-offset geometry, 2D data acquisition and processing flow) remains limited, mainly because of heterogeneities and complexity of ice bodies shapes. We examine the influence of subsurface heterogeneity and ice wedge geometry on imaging these structures, based on synthetic data for a 2D polygon scenario of successively increasing complexity. Subsequently, we apply our interpretation strategies for identifying ice wedges to field data from Siberia.

In order to improve the rockburst hazard forecast of rock mass in the development of korobkovskoe iron ore Deposit of KMA, in the laboratory conducted geophysical investigations of vibro-seismic method and method of acoustic emission under uniaxial compression of rock samples, selected in the mountain range of the mines. The dependence of the intensity of the vibration on the magnitude of mechanical stresses in the sample has non-monotonic character, and promising to identify rockburst-hazardous sites of the massif is the density parameter of the modules of amplitudes of acoustic emission signals. Also confirmed that the intensive destruction of rocks in the zone of influence of the free surface in acoustic emission signal is dominated by bipolar pulses.