Underground Shock Research Articles

ГЕОДИНАМІЧНИЙ СТАН ЗАКАРПАТСЬКОГО ВНУТРІШНЬОГО ПРОГИНУ ЗА РЕЗУЛЬТАТАМИ ДЕФОРМОМЕТРИЧНИХ СПОСТЕРЕЖЕНЬ У РЕГІОНІ

Background. The relevance of the research is determined by the gradual increase in local seismicity in the region, which occupies a peculiar geographical location, through which oil, gas and product pipelines pass, and in which critical infrastructure facilities are located that may be affected by the underground natural disaster. It is important to have information on the movements of the upper layers of the Earth's crust, their kinematics and dynamics, which significantly affect the stress-strain state of rocks and the release of energy from geomechanic processes. It is also necessary to investigate the influence of the region's geodynamics on the discharge of the stress-strain state of rocks. Methods. The research methodology is to construct time-dependent crustal displacements and compare velocities and accelerations of crustal movements in the intervals of anomalous modern lateral movements of the Earth's crust. The velocities and accelerations of crustal movements are calculated, the kinematics of movements and seismicity of the region are compared. Correlation analysis of the observed series is applied. To solve the tasks, we used the results of observations of horizontal crustal movements in the Oașh deep-seated fault area using a quartz strain gauge with a base of 24.5 m mounted in the adit of the Korolevo urban-type settlement. The seismic data were obtained using digital seismometers operating at the monitoring geophysical station of the Seismicity Department of the Carpathian region of S.I. Subbotin Institute of Geophysics of the National Academy of Sciences of Ukraine. Results. The article discusses the geodynamics of the Transcarpathian Inner Trough based on observations of modern lateral movements of the Earth's crust in the Oașh deep-seated fault area, which in 2021 were represented by rock extensions of +12.61x10-7. The physical parameters of geomotion in the region were calculated, the spatiotemporal distribution of local seismicity was established, and the relationship between seismic and geodynamic states in Transcarpathia in 2021 was studied. The variations of displacements of the upper layers of the Earth's crust over the entire period of deformation monitoring observations in Korolevo urban-type settlement (1999–2021) and the temporal distribution of local underground shocks were studied. Conclusions. The analysis of the spatio-temporal distribution of local seismicity and modern lateral movements of the Earth's crust over the entire period of deformation monitoring observations in the Oașh deep-seated fault area has indicated an increase in the seismicity of the region in the intervals of intense crustal movements and the presence of periods of crustal movement fluctuations for 12 years: familiar variable processes (expansion and contraction of rocks, the total magnitude of displacement fluctuations in the region of zero movements) were detected for 2–3 years. The most relevant and important are the periods of 9–10 years following these calm intervals, since during this time earthquakes are recorded and their frequency is also found to be increasing. The intensification of seismicity in the region is observed against the background of general rock extension, which occurs due to the steady age-related crustal movements. At the present stage, the current crustal movements are in a state of rock expansion, and if this trend does not change, an increase in seismicity in the region should be expected.

Dependence of Earthquake Energy on the Preparation Time of Underground Shocks

Dependence of Earthquake Energy on the Preparation Time of Underground Shocks

Energy Generation Process of Catastrophic Earthquakes in Turkey 2023 and the Driving Forces of Underground Shocks

Energy Generation Process of Catastrophic Earthquakes in Turkey 2023 and the Driving Forces of Underground Shocks

СТРОИТЕЛЬНАЯ СИСТЕМА РОССИИ НЕ ПРИЗНАЕТ ВОЗДЕЙСТВИЯ ПОВТОРНЫХ ЗЕМЛЕТРЯСЕНИЙ НА СТРОИТЕЛЬНЫЕ ОБЪЕКТЫ

Today, many learned builders know that earthquakes in the territory of, for example, a settlement can manifest themselves in the form of the first most powerful earthquake (main underground shock), which is usually followed by a series of weaker repeated earthquakes (repetitive shocks). There are many examples of such a sequence of manifestations of strong earthquakes in a certain territory, when tens of thousands of people die in destroyed buildings during repeated exposure earthquakes. It is thanks to these examples that scientists, builders, understand the main cause of death due to repeated earthquakes, which is the maximum permissible degree of damage formed in buildings under the influence of the first main earthquake. In addition, many builders are aware of many examples today when the intensity of the impact of a repeated earthquake on buildings was, for a number of reasons, stronger than the intensity of the effects of a major earthquake. However, contrary to the examples of the death of thousands of people in buildings during repeated earthquakes, in the construction system of Russia, the calculation of earthquake-resistant objects continues to take into account the impact of only one main earthquake. Therefore, the article substantiates the need to take into account the effects of earthquakes and repeated earthquakes in the calculations of earthquake-resistant buildings.

Development status and application prospect of semi-active vibration reduction technology for down-hole drilling tools

Domestic and foreign oil companies have been constantly increasing the research and development investment in underground shock absorber, to reduce the vibration and shock of drilling tool under hard rock drilling environments, enhance the rate of penetration and decrease drilling cost under the premise of ensuring the normal life of drill string components and stable bit weight. Based on this, this paper has focused on the working principal of magneto-rheological fluid (MRF) semi-active damper, the composition of MRF and its internal parameters’ impact on the damping characteristics, combining with the status quo at home and abroad of down-hole vibration technology. Meanwhile, the test analysis of semi-active damping technology was conducted. And the results showed that semi-active vibration technology had greatly weakened the vibration level while improved the rate of penetration, guaranteed the service life of bit and other drill-string components, reduced additional tripping times and effectively solved the problems of bit weight instability and low penetration rate etc., caused by drill vibration. Therefore, in the current situation of worldwide oil price downturn, it has become increasingly prominent to reduce cost and increase efficiency, and it’s particularly necessary to research on the shock absorbers of down-hole drilling tools in China.

The study of dissolved helium and radon concentrations in groundwaters of Southern Pribaikalie in connection with seismic processes

It is known that changes in geochemical fields may be due to the formation and development of earthquake foci. Hydrogeochemical fields at observation sites can be disturbed by underground shocks of sufficient energy, which occur at specific epicentral distances. Our study aimed to reveal these relationships by analysing the concentrations of helium and radon in groundwaters of Southern Pribaikalie, the area around Lake Baikal in Russia. Water samples were taken daily at 10 a.m. from artesian well No. 3 in Zeleny Mys, Irkutsk region. After water sparging, radon concentrations were measured by beta-detection Camera-01 and INGEM-1 (magnetic discharge indicator of helium) to determine helium concentrations. We analysed the concentration values in connection with 22 seismic events that occurred from 2010 to 2016 at the hydrogeochemical observation site (energy classes K of 10.4–14.5; epicentral distances of 40–750 km; conditional energy of K’>6). Based on the radon and helium concentration diagrams, specific regularities were established in the concentration variations before the earthquakes. Generally, concentration variations (increasing/decreasing) in excess of 1.5–2.0 standard deviations preceded earthquakes. This article presents the study results and discusses variations in the radon and helium concentrations, which are due to the seismic process and can be considered as a short-term precursor of earthquakes.

A project of creating atlas aftershocks of strong earthquakes

The Omori Law, which describes the repeated underground shocks after a strong earthquake, is written in the form of a nonlinear differential equation. An idea of the focal deactivation coefficient after the main shock is introduced. Two advantages of the new wording of the Omori Law are given. Firstly, there is an interesting possibility to naturally take into account exogenous and endogenous triggers affecting the earthquake source. Endogenous triggers in the form of round-the-world seismic echo and free oscillations of the Earth, excited by the main shock, are especially noted. The second advantage is that the differential aftershock equation makes it possible to put the reverse problem of the earthquake source physics. The essence of the inverse problem is to determine the deactivation coefficient from the data on the observed aftershock frequency. Examples of inverse problem solution are given. The project of creation of the Atlas of aftershocks on the basis of the solution of the inverse problem of the source, cooling down after a strong earthquake is offered.

A Project for an Atlas of Aftershocks Following Large Earthquakes

The Omori law for repeated underground shocks after a large earthquake is written here in the form of a nonlinear differential equation. We define a coefficient of deactivation for the rupture zone after the main shock. Two advantages of the new formulation are pointed out. First, there is now an interesting possibility for a natural incorporation of exogenous and endogenous factors that affect the rupture zone. We highlight endogenous triggers in the form of a circumnavigating seismic echo and free oscillations of the Earth excited by the main shock. The other advantage consists in the fact that the differential equation for aftershocks enables us to formulate the inverse problem for the physics of the rupture zone. The inverse problem reduces to the determination of the coefficient of deactivation based on observed aftershock frequency. Examples are given to illustrate the solution of the inverse problem. We propose to develop an atlas of aftershocks based on the solution of the inverse problem for the rupture zone that is “cooling” after a large earthquake.

Numerical Simulation of Response of Explosion Ground Shock to Buried Gas Pipeline

In this paper, by using nonlinear dynamical theory and Arbitrary Lagrange Eulerian (ALE) algorithm in LS-DYNA 3D finite element program, a method of numerical simulation is used to study dynamical response of buried gas pipeline underground shock wave of underground explosion. The simulation results shows that it is feasible for the numerical simulation method in this paper to study dynamical response of buried pipelines underground shock waves from explosion. the conclusion in this paper may provide significant reference for the risk evaluation and disaster prevention of buried gas pipeline.

Dynamic surface effects of underground copper ore mining in the Legnica Copper District, Poland

Abstract In the region close to Legnica, Poland, copper ore is mined at a depth of about 900 m by the process of explored chambers collapsing as a consequence of controlled explosions. These explosions generate underground shocks which propagate to the surface as seismic waves. This paper discusses the characteristics of these waves, their propagation through the rock mass, the vibrations they cause at the ground surface and their effect on certain structures at the surface. Some data on seismic energy are presented and discussed, including cases of medium and maximum energy, up to 10 10 J. Surface vibrations above the explored ore layers are analysed using the spectral amplitude – frequency approach. The correlation between source energy and measured magnitude is discussed, together with surface effects, in terms of existing MCS and MSK scales. A method for evaluating the degree of potential damage to structures caused by the vibrations is presented; this involves computational analysis in accordance with physical load models determined from measurements and simplified scales of vibration (SWD). Structural engineering designs for withstanding these paraseismic influences in these areas are also mentioned.

Effects of effects of earthquakes in the region of the Chirkeisk hydroelectric plant

1. Despite the great destructive force of the earthquake, it did not cause any serious impairment of the general stability of the canyon walls or of the supporting surfaces of the arch dam. 2. The results of the earthquake are indicative of the correctness of the technical solutions adopted for the industrial and civil buildings and for the slopes at the pit at the dam and the powerhouse, as well as of the correctness of the selection of the location, of the surface and underground structures. The results of the earthquake are indicative also of the high strength and reliability of the buildings and structures constructed, and of the high quality of the construction and erection work. 3. The dynamic characteristics of the underground shocks, as observed in the region of the Chirkeisk hydroelectric plant, considerably exceed the corresponding design values for earthquakes of that intensity, adopted on the basis of the current norms. 4. The material losses caused by the earthquake were on the order of 6.5 million rubles, and the main construction work was suspended over a period of 4–6 months.

Recent Local Rising of Land in the North-west of Europe

DURING January of 1894 the local papers of Sweden, Norway, and Finland reported the occurrence of underground shocks or tremblings of the ground, accompanied with noises. The zone seems to be east and west on about 60° of latitude, from about Drammen in Norway across Sweden to Hango on the southern part of Finland.