Influence of vibrations on structures

One type of occasional structural load is a seismic load. Earthquakes and blasts are typical sources of vibrations, but vibration generated during urban tunnel construction can represent a significant problem. Evaluation of the harmful impact of vibrations transmitted through rock massif into buildings is solved using experimental measurements, detailed analyses of measured signals, knowledge of geological pattern and constructional analysis. Seismic load of structures due to earthquakes is solved using the EUROCODE 8 standard. The earthquake movements at a certain location on the surface are determined by an elastic response spectrum to the ground acceleration. Eurocode 8 puts emphasis especially on the robust foundations and simplicity of construction systems. It is also mentioned vibration effect on historical buildings and effect under the surface, for example, in mine spaces. Historical structures are usually even more prone to vibration damage than, for example, typical wood-frame homes. The greater concerns over historic structures arise from the design, structure age, building materials and building methods used. The peak values of vibration generated by earthquake decrease with depth; the decrease is faster in shallow layers compared with the deeper part. Technical vibrations differ from natural earthquakes, for a comparable value of maximum vibration amplitudes, especially in the frequency range of the signal and mostly its duration. Evaluation of technical seismicity is more complicated because there are usually used national standards. To document some common information about vibration effects on structures, some experimental measurements are presented. Examples of real wave patterns document common shapes and also signals with significant resonant vibrations. Very interesting is an example of resonant vibration that was generated as the influence of basin structures on the shape of wave patterns due to quarry blasts. To obtain complete information, measurement system has to keep sufficient parameters, especially the frequency range of the whole seismic channel, sampling frequency, and proper anchoring of the sensor. The basic methodology for evaluation of vibration on structures is outlined.Web of Science23331129

Analysis of Seismic Responses of Rock Massif to Explosive Impacts with Using Nonlinear Methods

When conducting mining operations in high-stress rock massive, technogenic seismicity is manifested, with forecasting and prevention issues being given much attention in all countries with a developed mining industry. An important role here belongs to the short-term forecast; the methodology for identifying criteria for it is still a problem, both in mining and in seismology. From the point of view of the paradigm of physical mesomechanics, which includes a synergetic approach for changing the state of rock massive of material with different compositions, this problem can be solved with the help of monitoring methods tuned to the study of hierarchical structural media. Changes in the environment, leading to short-term precursors of dynamic phenomena, are explained within the framework of the concept of self-organized criticality, for which the central moments are heterogeneity and nonlinearity. Introduction of the proposed integrated passive and active geophysical monitoring, aimed at studying the transient processes of redistribution of the stress–strain and phase states, can contribute to the prevention of catastrophic dynamic manifestations during the development of deep-lying deposits. Methods of active geophysical monitoring should be tuned to a model of a hierarchical heterogeneous medium and provided with new results of propagation of wave fields in layered block media with inclusions of a hierarchical structure

Innovation approaches in seismic microzonation tailing dump designing

Рассматриваются современные подходы оценки влияния локальных условий на сейсмическую опасность территорий. На примере хвостохранилищ горно-обогатительных комбинатов показано, что привлечение цифровых моделей среды и расчетных методов является важным элементом при прогнозировании влияния строения грунтовой толщи, ее физических свойств и антропогенного рельефа на усиление сейсмических колебаний грунта.Розглядаються сучасні підходи оцінки впливу локальних умов на сейсмічну небезпеку території. На прикладі хвостосховищ гірничо-збагачувальних комбінатів показано, що залучення цифрових моделей середи і розрахункових методів є важливим елементом при прогнозуванні впливу побудови грунтової товщі, її фізичних властивостей та антропогенного рельєфу на посилення сейсмічних коливань грунту.Current approaches of assess the impact of local conditions on the seismic hazard areas are considered. On the example of ore-dressing and processing enterprises tailings is shown that engaging of digital environment models and calculation methods is an important element in predicting the effect of the structure of a ground layer, its physical properties and anthropogenic relief to seismic ground motion amplification

Multivariate Spatiotemporal Hawkes Processes and Network Reconstruction

There is often latent network structure in spatial and temporal data and the tools of network analysis can yield fascinating insights into such data. In this paper, we develop a nonparametric method for network reconstruction from spatiotemporal data sets using multivariate Hawkes processes. In contrast to prior work on network reconstruction with point-process models, which has often focused on exclusively temporal information, our approach uses both temporal and spatial information and does not assume a specific parametric form of network dynamics. This leads to an effective way of recovering an underlying network. We illustrate our approach using both synthetic networks and networks constructed from real-world data sets (a location-based social media network, a narrative of crime events, and violent gang crimes). Our results demonstrate that, in comparison to using only temporal data, our spatiotemporal approach yields improved network reconstruction, providing a basis for meaningful subsequent analysis --- such as community structure and motif analysis --- of the reconstructed networks

High-rate GPS positioning for tracing anthropogenic seismic activity. The 29 January 2019 mining tremor in Legnica- Głogów Copper District, Poland

High-rate GNSS observations are usually studied in relation to earthquake analysis and structural monitoring. Most of the previous research on short-term dynamic deformations has been limited to natural earthquakes with magnitudes exceeding 5 and amplitudes equal to several dozen centimetres. High-frequency position monitoring via GNSS stations is particularly important in mining areas due to the need to monitor mining damages. On 29 January 2019 (12:53:44 UTC), an M3.7 event occurred in the area of Legnica-Głogów Copper District. This study presents GPS-derived displacement analysis in relation to seismological data. Station position time series were determined by double differencing and Precise Point Positioning. The peak ground displacement was 2–14 mm. The correlation coefficients between GPS and seismological displacement time series reached 0.92. A statistical evaluation of GPS displacement time series was carried out to detect an event using only GPS observations