scholarly journals A Microseismicity-Based Method of Rockburst Intensity Warning in Deep Tunnels in the Initial Period of Microseismic Monitoring

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2698 ◽  
Author(s):  
Guangliang Feng ◽  
Manqing Lin ◽  
Yang Yu ◽  
Yu Fu
Keyword(s):  
Cluster Analysis ◽  
Geotechnical Engineering ◽  
Initial Period ◽  
Engineering Application ◽  
Microseismic Monitoring ◽  
Sichuan Province ◽  
Economic Losses ◽  
Hydropower Station ◽  
The Novel ◽  
Jinping Ii Hydropower Station

Rockburst disasters in deep tunnels cause serious casualties and economic losses. It is a great challenge to make a warning for rockbursts in geotechnical engineering. In this work, a microseismicity-based rockburst intensity warning method is proposed that is suitable for use in deep tunnels in the initial period of microseismic (MS) monitoring. The method first involves collecting information on a sample of no more than five cases. Then, the event to be analyzed is combined with the sample events and subjected to cluster analysis. Finally, a rockburst intensity warning is generated according to the results of the cluster analysis or after a second cluster analysis. It is a comprehensive, multi-parameter rockburst intensity warning method that only needs a few rockburst cases for input which makes it suitable in the initial period of MS monitoring. The method also incorporates the novel idea of a second cluster analysis. An engineering application based on deep tunnels in the Jinping II hydropower station in Sichuan Province, China, shows that the rockburst intensity warning results based on the proposed method agree well with the actual situations in four tests carried out. The method will enrich the techniques used to warn of rockbursts based on microseismicity.

scholarly journals Microseismic Monitoring of Energy Changes in Deep Tunnels during the TBM Tunneling of the Jinping II Hydropower Station

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Duanyang Zhuang ◽  
Ke Ma ◽  
Chunan Tang ◽  
Zhengzhao Liang ◽  
Zhenwei Wang
Keyword(s):  
Control Method ◽  
Microseismic Monitoring ◽  
Surrounding Rock ◽  
Hydropower Station ◽  
Rock Masses ◽  
Spatial And Temporal Patterns ◽  
Tunnel Section ◽  
Headrace Tunnel ◽  
Jinping Ii Hydropower Station ◽  
And Control

The TBM tunneling at the Jinping II hydropower station in Southwest China has received extensive concerns around the world because of its large engineering scale and the high rockburst risks faced in the tunnel advancement. The associated energy changes of rockbursts and control method for safe TBM tunneling are to be further investigated. A movable microseismic (MS) monitoring system was established to capture the MS events and rockbursts when the TBM excavated the headrace tunnel #1 at the Jinping II hydropower station. The spatial and temporal patterns of the energy changes in the tunnel rock masses were studied. Meanwhile, the evolution of a rockburst encountered in front of the TBM excavation face was revealed, and the performance of the top pilot tunnel method on the reduction of the rockburst risks in the headrace tunnel #1 was evaluated based on the energy changes of the surrounding rock masses. It can be concluded that energy accumulation and energy release firstly occurred in the surrounding rock masses at the southern end of the top pilot tunnel section of the headrace tunnel #1. Then, energy transference of the rock masses took place from the southern end to northwest of the top pilot tunnel giving rise to the occurrence of a moderate rockburst about 30 m in front of the tunnel. However, no rockbursts appeared when the TBM excavated through the top pilot tunnel section of the headrace tunnel #1. Therefore, the top pilot tunnel method really works in reducing the risks of rockbursts during the TBM tunneling in deep tunnels.

Microseismic Monitoring of Strainburst Activities in Deep Tunnels at the Jinping II Hydropower Station, China

2015 ◽  
Vol 49 (3) ◽  
pp. 981-1000 ◽  
Author(s):  
N. W. Xu ◽  
T. B. Li ◽  
F. Dai ◽  
R. Zhang ◽  
C. A. Tang ◽  
...  
Keyword(s):  
Microseismic Monitoring ◽  
Hydropower Station ◽  
Jinping Ii Hydropower Station

scholarly journals Sex Differences in Spatial Activity and Anxiety Levels in the COVID-19 Pandemic from Evolutionary Perspective

2021 ◽  
Vol 13 (3) ◽  
pp. 1110
Author(s):  
Olga Semenova ◽  
Julia Apalkova ◽  
Marina Butovskaya
Keyword(s):  
Environmental Risks ◽  
Economic Losses ◽  
General Level ◽  
The Novel ◽  
Health Attitudes ◽  
Spatial Activity ◽  
Sexual Specialization ◽  
The Face ◽  
Novel Virus ◽  
Virus Spreading

Despite the enforced lockdown regime in late March 2020 in Russia, the phenomenon of the continued virus spreading highlighted the importance of studies investigating the range of biosocial attributes and spectrum of individual motivations underlying the permanent presence of the substantial level of spatial activity. For this matter, we conducted a set of surveys between March and June 2020 (N = 492). We found that an individual’s health attitude is the most consistent factor explaining mobility differences. However, our data suggested that wariness largely determines adequate health attitudes; hence, a higher level of wariness indirectly reduced individual mobility. Comparative analysis revealed the critical biosocial differences between the two sexes, potentially rooted in the human evolutionary past. Females were predisposed to express more wariness in the face of new environmental risks; therefore, they minimize their mobility and outdoor contacts. In contrast to them, the general level of spatial activity reported by males was significantly higher. Wariness in the males’ sample was less associated with the novel virus threat, but to a great extent, it was predicted by the potential economic losses variable. These findings correspond to the evolutionary predictions of sexual specialization and the division of family roles.

Microseismic monitoring of columnar jointed basalt fracture activity: a trial at the Baihetan Hydropower Station, China

2014 ◽  
Vol 18 (4) ◽  
pp. 773-793 ◽  
Author(s):  
Bing-Rui Chen ◽  
Qing-Peng Li ◽  
Xia-Ting Feng ◽  
Ya-Xun Xiao ◽  
Guang-Liang Feng ◽  
...  
Keyword(s):  
Microseismic Monitoring ◽  
Hydropower Station ◽  
Columnar Jointed Basalt ◽  
Baihetan Hydropower Station

Impact of natural hazards on the evolving COVID-19 pandemic: cases from Greece

2021 ◽  
Author(s):  
Maria Mavrouli ◽  
Spyridon Mavroulis ◽  
Efthymios Lekkas
Keyword(s):  
Built Environment ◽  
Natural Hazards ◽  
Local Population ◽  
World Health ◽  
Economic Losses ◽  
The Novel ◽  
Hydrological Hazards ◽  
Eastern Aegean ◽  
The Impact ◽  
Post Disaster

<p>The first confirmed COVID-19 case was reported in December 2019. Over the first months of 2020, the novel SARS-CoV-2 virus was spread worldwide resulting in the declaration on March 11, 2020 of a global COVID-19 pandemic by the World Health Organization. The evolving pandemic has resulted in over 1900000 fatalities worldwide (as of January 8, 2021), while all sectors of the everyday life has been affected in numerous and varied ways. Natural hazards did not stop for the novel coronavirus. When the natural hazards cross the path of an evolving pandemic, compound emergencies emerge and are characterized by various effects and new unprecedented challenges.</p><p>Greece was no exception. Geological, hydrological and meteorological hazards took place in several parts of the country and they affected the local population, the natural and the built environment including buildings, infrastructures and lifelines. Among the most destructive effects in terms of human and economic losses was the March 21, 2020, Mw=5.7, Epirus (northwestern Greece) earthquake, the August 9, 2020, Evia (central Greece) flood, the September 17, 2020, Ianos medicane and the October 30, 2020, Mw=7.0, Samos (Eastern Aegean Sea) earthquake.</p><p>In order to identify the potential impact of the aforementioned disasters on the evolution of the COVID-19 pandemic in the disaster-affected areas, the officially reported laboratory-confirmed daily COVID-19 cases for the pre- and post- disaster periods from the disaster-affected areas were used. The impact of disasters in the evolution of the pandemic in the studied disaster-affected areas comprises increasing and decreasing trends and stability of the COVID-19 cases during the post-disaster period. More specifically, the geological and the hydrological hazards and the induced disasters negligibly affected the evolution of pandemic in the affected areas, while the hydrometeorological hazards resulted in increasing trends of the post-disaster reported COVID-19 cases in various affected areas.</p><p>The detected trends are strongly associated with the pre-existing viral load and infection rate in the disaster-affected areas, to the emergency response actions adapted to adopt provisional measures for the mitigation and elimination of COVID-19 consequences, to demographic features of the affected areas and to the intensity of the induced disasters and their effects on the local population (fatalities and injuries), the natural environment (primary and secondary environmental effects) and the built environment (structural damage to buildings, infrastructures and lifelines).</p>

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