Работа посвящена аспектам представительности сейсмического микрорайонирования, являющегося одной из обязательных оценок, предваряющей гражданское и промышленное строительство. В дополнение к практикуемому подходу и в соответствии с нормативной документацией авторы предлагают параметрическое дешифрирование дистанционной основы в форме трассирования геодинамических зон и элементов геоблокового строения, где ведущим маркером сейсмогенных рисковых зон избрана аномалия пространственной изменчивости геополя, совпадающая с дискордантным пересечением локализованных морфоструктур. Верификация этого маркера достигается за счет вывода картографического образа распределения в пределах полигона приращения сейсмической балльности, детализируемого на основании аппроксимационных зависимостей.Ключевые слова: сейсмическое микрорайонирование; верхняя часть разреза; аппроксимация; дешифрирование; дистанционная основа; цифровая модель рельефа; геодинамическая зона

No abstract

Microstructured materials, namely metamaterials, are one of the most relevant topics of the recent period due to their interdisciplinary nature. Driven by their wide range of applications, we provide an overview of a class of elastic solids which embed dynamic microstructures capable of trapping energy when subject to dynamic loads. Based on the recently developed modeling approaches, we show several applications related to wave cloaking, filtering and also multi-structured surfaces, often referred to as meta-surfaces. These culminate in the analysis of a practical example, based on a real-life recent seismic event induced by a hydrofracture exploration. The latter shows the viability of the vibration analysis in the assessment of the seismic response, and also the role of meta-surfaces as localisers of vibrations, e.g. suggesting non-periodic earthquake tolerant design strategies of housing estates.

The standard problem of engineering geophysics, solved for road and house building and other construction types, is in the localization of areas with increased mobility in the upper part of a geological cross-section and in the parameterization of this mobility in terms of seismic intensity. There is a standard approach, according to which researchers assess the elastic strength characteristics of the core to a depth of about 30 m, implement the accumulation of seismogram observations, simulate accelerograms for particular conditions and, taking into account the data of complex geophysical methods, calculate the increment of seismic intensity as one of the parameters of a seismic hazard. The final result of this approach has the form of a seismogenic hazard map and a set of recommendations including the consideration of identified areas with a significant increasing seismic intensity increment, due to the peculiarities of the geological structure of polygons. This result is reliable, but very expensive, and requires the development of primary estimations of the rock massif with reduced resistance to external loads, which would optimize the efforts in engineering drilling and in field geophysical measurements in order to densify their spatial grid in the vicinity of a priori known positions with an increased seismogenic hazard. In addition, relatively sparse grids of wells, as well as local geophysical profiles laid under conditions of a complicated landscape, do not accurately localize risky areas in order to focus the attention of builders on strengthening the specific part of raised constructions. Following the wishes of our customers and relying on long-term testing of our interpretational developments, we formed an approach to primary hazard forecasting based on remote sensing data and digital elevation models, which can be classified as data with relatively free access. This article presents the results of research which was based on these free-of-charge data and which was developed in the field of construction of ground engineering structures for agricultural purposes, where one of the factors of mobility in the upper part of a cross-section is intensive karstification. Basically, the construction area according to the general seismic zoning maps is seismologically passive, though the relatively fast dynamics of karst determines the relevance of the detailed seismic zoning. The results of our interpretations are verified by deep geological and structural reconstructions based on wave analogies. The representativeness of the final forecast was confirmed by subsequent seismic assessments, which is related to the scientific novelty of the presented article. The authors’ technology for the qualitative and quantitative interpretation of remote sensing data and digital elevation models with high resolution provides the opportunity to increase the spatial resolution of seismic microzonation forecasts, implemented by standard geophysical methods, and it determines the practical significance of completed research.

A new approach to seismic analysis has been introduced and demonstrated for a sequence of recent seismic events recorded in the Blackpool region of Lancashire, UK. The seismic activity, induced by an industrial hydraulic fracturing at a depth exceeding 2 km, had the extent of registered surface elastic vibrations reaching a distance exceeding 15 km. The analysis is based on the study of elastic fields, three-dimensional extrapolations of the landscape and the novel reconstruction of a three-dimensional digital model of seismic map boundaries and vertical profiles. The verification of the proposed approach is carried out via the comparison with published data of the Blackpool seismic events, combined with the new spectral analysis linked to the identified regions of seismic activity. The latter was accompanied by a finite-element simulation of vibrations for an elastic layer of variable thickness, approximating the test region. The analysis and numerical modelling have demonstrated consistency with the dynamic nature of structural stratification of the geological systems, and in addition, the predictive nature of the modelling work was demonstrated by the comparison of the model eigenmodes with the published parameters of registered earthquakes in the Blackpool area. This article is part of the theme issue ‘Wave generation and transmission in multi-scale complex media and structured metamaterials (part 1)’.