The potential of hydroacoustic methods widely used in coastal engineering geophysical survey is limited in the presence of gas-saturated bottom sediments. Under unfavourable conditions it is advisable to use electric prospecting methods. This article analyses the efficiency of modern electric resistivity tomographic (ERT) technologies of the surface and seabed observation systems for studying the geological sections in coastal water areas. Basic geoelectric and electric resistivity tomographic models are synthesized to assess the influence of water salinity and lithological composition of sediments on the results of marine electric prospecting. Petrophysical modelling data showed that, along with the influence of pore water mineralization on the ratio of specific electric resistivity values ​​of dispersed soils, the mineral composition of clay minerals has a significant effect. This effect is manifested as a shift in the position of the inversion point of specific electric resistivity values ​​of sandy-clayey soils with increasing cation exchange capacity ​​​​typical of different mineralogical types of clays. Results of numerical modelling of electric resistivity tomography sections using surface and seabed observation systems demonstrated that the seabed measurement system provides reliable information on geoelectric structure of sandy-clayey sediment sections, while the sections obtained from the ERT survey on water surface exhibit distortions in the geoelectric section structure and false anomalies. The advantage of seabed ERT for studying the geological structure of coastal marine areas was ascertained. Experimental work in the Luga Bay water area in the Gulf of Finland confirmed the efficiency of the seabed ERT for increasing the reliability of cross-well geological interpolation when constructing composite geological and geophysical sections. The use of seabed ERT ensured a continuous tracking of geoelectric boundaries corresponding to different lithological species in seabed sandy-clayey sediments.

Landslides are among the most dangerous geological processes, posing a threat to all engineering structures. In order to assess the stability of slopes, complex engineering surveys are used, the results of which are necessary to perform computations of the stability of soil masses and assess the risks of landslide development. The results of integrated geological and geophysical studies of a typical landslide slope in the North-Western Caucasus spurs, composed of clayey soils, are presented. The purpose of the work is to increase the reliability of assessing the stability of a landslide mass by constructing a 3D model of the slope, including its main structural elements, identified using modern methods of engineering geophysics. Accounting for geophysical data in the formation of the computed 3D model of the slope made it possible to identify important structural elements of the landslide, which significantly affected the correct computation of its stability.

The article presents the results of comprehensive studies carried out by the research team of Saint Petersburg Mining University in cooperation with the specialists from the State Museum-Preserve "Tauric Chersonese" in 2019. The purpose of the work was to discover and map antique and medieval crypts (ancient burial structures) on the territory of suburban necropolis of Tauric Chersonese in the Karantinnaya balka. The complex of geophysical methods included continuous ground penetrating radar sounding at two center frequencies of 350 and 500 MHz and contactless electrical tomography. To minimize spatial errors in the process of studies, topographic and geodetic works were carried out. For the first time wave electromagnetic effects were identified, which indicated the positions of hidden underground crypts. Geological factors were established that are favorable for cutting crypts in the layered thickness of Sarmatian limestones. The obtained results allowed to justify the feasibility of continuing geophysical works at the necropolis in order to study interior space of the discovered crypts and to determine the boundaries of archaeological heritage.

A method for estimating the filtration factor of sandy clay soils is considered on the basis of a joint interpretation of the data of a set of methods of engineering electrical exploration, including electrical resistivity tomography and ground penetrating radar studies. The solution of this problem is based on the use of known empirical connections between the imaginary and real parts of the complex dielectric permittivity, specific electrical resistance, and Q factor. An example of the effective joint use of the ground penetrating radar and non-contact electrical resistivity tomography shows how to obtain qualitative and quantitative estimates of a changing filtration factor in a draining road layer. It is necessary to use precise engineering geological information in order to provide the required estimates. The proposed approach makes it possible to describe continuous profiles of a pavement and underlying layers by ground penetrating radar and electrical resistivity tomography, as well as to assess soil properties when conducting an electrical survey from the surface of asphalt concrete pavement. Recommendations for the implementation of the developed methods of complex engineering and geophysical research are given for solving issues of repair work design, supervision, and quality control of road construction.

The possibilities of GPR method to assess the degree of fracturing rocks. The mathematical modeling of the wave electromagnetic fields of rock fracture arrays. We formulate the classification of the wave electromagnetic fields on the rock mass, with varying degrees of fracturing. The prospects of applying the method of GPR in the study of rock fractures.

The GPR-method showing high resolution, great performance and sensitivity to minor variations in the composition and conditions of soils and material has assumed a role of the leading geophysical method for looking at the upper part of the geological section. This paper presents the advanced directions of GPR prospecting for engineering problems solution.

Results of the first application of GPR surveys of a mine cage for the purpose of an estimation of a technical condition barring and outbarring spaces on an example of a ventilating trunk «VC-1», mine «Octyabr’skiy» are considered.

The GPR-method showing high resolution, great performance and sensitivity to minor variations in the composition and conditions of soils and material has assumed a role of the leading geophysical method for looking at the upper part of the geological section. This paper presents the advanced directions of GPR application for engineering problems solution.

Blast tube geophysical field anomalies are often of low intensity and commensurate with interference fields that are associated with localized inhomogeneities in the upper part of the geologic section.

The anomaly of the harmonic approximation of the ∆T magnitude of a three-dimensional source is generally formed by five components of the magnetic field...

Deterministic methods of interpretation are developed, as a rule, on the basis of formulas valid for a horizontal surface. But a physical surface can be as complex as desired, and it can be approximated more often and with less error by an inclined plane rather than by a horizontal plane ...

To solve the formulated problem, the magnetic field is usually used along a single profile passing over the center of the ball and through the extrema of the anomaly Z ...

The careful attitude in our country to historical monuments, enshrined by the law “On Protection and Use of Historical and Cultural Monuments” adopted in 1976 by the Presidium of the Supreme Soviet of the USSR, urgently requires the introduction of new methods in the field archaeological practice, which without prejudice to the study of monuments would allow to reduce the cost and speed up the acquisition of information required by the archaeologist ...