Dmitriy Malovichko

Institute of Mine Seismology

In October 2006 a serious accident happened in Berezniki-1 mine of the world’s second largest Verkhnekamskoye potash deposit. The integrity of the waterproof stratum which separates mine workings from aquifers was broken and an uncontrolled flooding of the mine had began. The accident resulted in the appearance of several potential problems associa...

When investigating a large or damaging seismic event in a mine, it is possible to be in the situation where either a conventional source mechanism inversion technique is not applicable due to poor data or the interpretation of the inverted source mechanism in terms of a planar slip model does not appear adequate for the observed damage or geologica...

A technique which makes it possible to improve the linear elastic stress model of a rock mass is suggested. It includes two components: (1) Misfit between the observed source mechanisms of seismic events and assumed stress state. The misfit is based on Coulomb Failure Stress and takes uncertainty of location and finite size of the sources into acco...

An approach to assess seismic and ground motion hazard associated with scenario(s) of future mining is suggested. The key element of the approach is the modelling of expected seismicity using the Salamon–Linkov method (Malovichko & Basson 2014) and combining the catalogues of modelled and observed seismic events. The modelling domain is discretised...

Numerous tunnels of the extraction and undercut levels of the Pilar Norte sector experienced violent damage on 24 December 2011. A seismic event with a moment magnitude of 2.4 was recorded by the mine-wide seismic system at the same time. It is difficult to explain the observed damage with peak particle velocities/peak ground velocities calculated...

The assessment of expected ground velocities at the perimeter of tunnels is important for the quantification of dynamic demand imposed on ground support. Two types of ground velocities need to be considered. The first is the velocity of ground motion/shaking due to a stress wave from a remote (relative to the tunnel) seismic event, which is used to...

In the context of crustal seismology, a number of methods have been proposed for inferring stress state information from seismic data (moment tensors). These methods rely on assumptions that are often violated by mining-induced seismicity. For example, they require that sources are purely slip-type, whereas crush-type sources (failure near/around e...

During a strainburst, there is a simultaneous energy and displacement demand placed on the support system. To better understand the evolution of this demand, high-resolution, dynamic, two-dimensional modelling was conducted of self-initiated strainbursting near an isolated circular tunnel. By analysing the results of this modelling, estimates are m...

Seismic monitoring data acquired at mines can be used to infer the characteristics of coseismic strain, including amount, orientation of principal directions and type (deviatoric, volumetric explosive or implosive). This strain corresponds to plastic strain increment if seismic events represent episodes of sudden deformation in confined environment...

A method is proposed for the calibration of a mine-scale numerical stress models using seismic monitoring data. The method is based on comparing the gridded observed and modelled seismic potency of slip-type seismic events according to a misfit/cost function. Expressions are derived for the gradients of this misfit function with respect to the para...

Assessing the depth of rock fracturing around tunnels is of critical importance for the design of ground support systems in strainbursting ground. Considering the heterogeneity of the rock, explicit modelling of stress-fracturing around tunnels at such a massive scale is a numerically demanding task. Previously, a semi-empirical approach to evaluat...

A surprisingly large mining-induced seismic event occurred in the LKAB Kiirunavaara Mine (Sweden) on 18 May, 2020 at 03:11 (local time). The estimated moment magnitude was 4.2. The event caused extensive damage in a large section of the mine. The production in the area is not yet resumed, even by the beginning of 2022 (~20 months after the event)....

This paper considers dynamic fracturing of the rockmass surrounding a tunnel statically loaded by compressional stress as a possible source of seismic events in underground mines. This begins with two-dimensional dynamic modelling of failure for six plausible scenarios. In each case, the seismic source derived from these models has significant nega...

The general theory for the description of seismic sources is briefly discussed. The effect of excavations on seismic radiation is considered. Expressions for seismic source mechanisms in terms of the geometrical and mechanical parameters of source processes are provided for the following cases: fault slip and shear failure in a confined environment...

Highly stressed excavations in hard brittle rock may fail by self-initiated, triggered or dynamically loaded strainbursts (Moss and Kaiser 2021). The low-frequency part of seismic radiation associated with strainbursts is described by a crush-type seismic source mechanism with a significant negative (implosive) isotropic component and a ‘pancake-sh...

A 1D model describing the response of unsupported or supported blocks or wedges of rock near an excavation to an incoming stress wave is presented. The model is based on a non-linear force-displacement relation which includes an elastoplastic positive branch (corresponding to displacement into the excavation) and an elastic negative branch (corresp...

In underground mines, episodes of sudden inelastic deformation in the rockmass are often induced by mining and are therefore localized near the excavations. The seismic radiation associated with such deformation can be described by a point seismic source using a volume integral of the stress-free strain (or incremental plastic strain)—expression (1...

Оценка сейсмической опасности в рудниках имеет ряд отличий от подобной оценки для тектонических землетрясений: a) в рудниках сейсмичность вызвана извлечением горных пород, что делает оценку опасности зависимой от планируемых горных работ; б) значительная часть сейсмических событий в рудниках имеет механизмы очагов, отличные от механизмов тектоничес...

An approach to model seismicity induced by mining was proposed by M.D.G. Salamon and developed further by A.M. Linkov. We suggest a variation of Salamon-Linkov method that does not require a priori assumptions about sizes, orientations and locations of flaws, reducing the amount of input data. The algorithm places a 3D grid over the model domain an...

Seismic networks operated in the mines of the Verkhnekamskoye potash deposit routinely register seismic events associated with mining. Intensive low-frequency (0.5 - 2 Hz) Rayleigh waves occur on the waveforms of s ome events (so-called "low-frequency" events). Classical seismological source model in the form of expanding shear crack does not repro...

Verkhnekamskoye potash deposit (VPD) is the only exploited potash deposit in Russia. It is second in the world on reserves after the Saskatchewan deposit in Canada. The first mine at the VPD was brought into production in 1933. Intensive mining began in the middle of the 1980s, when 6 mines were in operation. Ores are extracted from potash beds at...

Seismic events and pillar failures observed in two platinum mines in the Rustenburg area, South Africa, were nvestigated. We studied the sources of approximately 300 largest seismic events recorded in 2009. Moment tensors of these events were estimated from amplitudes and polarities of P- and S-waves. The inverted mechanisms contain isotropic implo...

Seismic monitoring systems installed in mines record seismic signals from various dynamic processes – fracturing in rock mass, production and development blasts, impacts and vibration of machinery, etc. It is important to classify the recorded seismic events before doing most kinds of analysis of seismic data. For instance, the assessment of seismi...

Seismic rock mass response to mining is somewhat different than processes leading to and resulting from tectonic earthquakes. The seismicity observed in mines is driven by extraction of rocks rather then tectonic forces. Loading is faster and an interaction of seismic sources with openings and blasting create a variety of source mechanisms. amage i...

The paper addresses the methodic questions of arrangement and implementation of local temporal seismologic observations targeting research on karst. We describe an approach for the quantitative assessment of the feasibility for recording the seismic effect of dynamic phenomena accompanying the karst processes. The approach copes with the specific f...

For over 13 years a routine seismic monitoring has been carried out at six of the mines in the world’s second largest potash deposit, the Verkhekamskoye, Perm region, Russia. The observed level of seismicity is rather low in the mines. On average about 1-2 events with seismic energies from 100 J up to 50 kJ are recorded daily. The seismicity doesn’...

ISS International, ЮАР Введение В последние годы новым направлением в комплексе исследований, способствующих повышению безопасности и экономической эффективности открытых горных работ, ста-новится микросейсмический мониторинг. Данная разновидность мониторинга основана на представительной регистрации сейсмических колебаний от небольших актов хрупког...

An approach to the description of the seismic effect related to dynamic processes in mines is proposed. In terms of this approach, the notion of an equivalent seismic point source is mathematically formulated in order to describe the low frequency part of the displacement field in the far-field zone. A method of estimating parameters of the equival...

In May 2002, both active- and passive-source surface wave data were acquired using 4-channel arrays at six selected bridge sites in southeast Missouri. Processing of acquired data (increase of signal-to-noise ratio, estimation of phase velocities) was carried out and dispersion curves of Rayleigh wave phase velocities were constructed. Each fundame...

Common characteristics of the seismicity in the Ural Region are considered. New approaches to control of natural and technogenic earthquakes are described. These approaches have become possible owing to the up-to-date seismological network of 6 digital seismic stations developed in the Western Ural. The data obtained during continuous 4 year monito...

In May 2002, Spectral Analysis of Surface Wave (SASW) data were acquired at six selected bridge sites in southeast Missouri. Each acquired SASW data set was processed and transformed into a site- specific vertical shear-wave velocity profile to depths on the order of 60 m. The SASW shear-wave velocity data were compared to other geotechnical data t...

Waveforms obtained during underground seismic activity monitoring at the mines of Upper Kama potash deposit (UKPD) exhibit an interesting structure. Intensive low- frequency (f < 4 Hz) wavetrains are found at the final parts of seismograms except for compressional (P) and shear (S) waves. Numerical modeling was carried out with the aim of clearing...

Routine seismic monitoring in mines enables the quantification of exposure to seismicity and provides a logistical tool to guide the effort into the prevention and control of, and alerts to, potential rock mass instabilities that could result in rock bursts. One can define the fol-lowing five specific objectives of monitoring the seismic response o...