The application of the non-explosive expansion material （NEEM） is widely used as the controlled fracture method in quarry min- ing, especially in hard rocks. The pressure of NEEM is an important parameter in causing...The application of the non-explosive expansion material （NEEM） is widely used as the controlled fracture method in quarry min- ing, especially in hard rocks. The pressure of NEEM is an important parameter in causing rock fracture. An empirical model based on hole spacing was developed to determine the pressure of NEEM in the rock fracture process. Primarily, the empirical model was developed by the mathematical method, utilizing dimensional analysis. Then, the Phase2 code, which is based on the finite element method, was utilized to predict crack growth in rocks. The results of numerical analysis show slight deviations from the empirical model. Hence, the polynomial re- gression analysis was used to modify the model. Finally, the modified model shows a good agreement with the results gained from numerical modeling.展开更多
The I48TN is one of the 60 International Monitoring System (IMS) stations of the Comprehensive nuclear Test Ban Treaty Organization (CTBTO), characterized by its location in the heart of the IMS Infrasound network. Th...The I48TN is one of the 60 International Monitoring System (IMS) stations of the Comprehensive nuclear Test Ban Treaty Organization (CTBTO), characterized by its location in the heart of the IMS Infrasound network. The ability of the International Monitoring System (IMS) infrasound network to detect atmospheric nuclear explosions and other signals of interest is strongly dependent on station-specific ambient noise. This ambient noise, includes both incoherent wind noise and real coherent infrasonic waves. Infrasound analysis software detects tens to hundreds of events per day which consume a lot of time for the Infrasound analysts, to define and categorize events where around 90% of the detections are coherent noise. This study analyzed the importance of the synergy between infrasound and seismic data, and provided the infrasound data analyst with the most important local coherent infrasound sources in the region as recorded by the IMS station I48TN, in order to reduce the workload of the analysts and give them a clear view on the coherent noise affecting this station for better discrimination between events of interest like nuclear explosions and coherent sources. DTK_GPMCC and DIVA software were used to perform this study. Geotool software from the International Data Centre (IDC) was used in analysing seismic data from the Tunisian IMS station KEST. The result of this study allowed the characterization of the most important coherent local infrasound sources (Mines and Quarries) which are considered as coherent noise to I48TN station and correct parameters in some reference events in the Reference Event Database source of the International Data Centre.展开更多
The Valmalenco area(central Alps,northern Italy)is well-known for the widespread mining and quarrying activities.Serpentinites are extracted and processed as valuable dimension stone in open-cast quarries,and a big un...The Valmalenco area(central Alps,northern Italy)is well-known for the widespread mining and quarrying activities.Serpentinites are extracted and processed as valuable dimension stone in open-cast quarries,and a big underground mine provides talc as industrial mineral.The presence of long-fiber chrysotile veins,especially in the eastern part of the valley,gave rise in the past to widespread mining activity,particularly between the end of the XIX century and 1975,leaving huge amounts of mining waste and tailings.In recent times,part of the tailings have been stabilized and reclaimed,covered with soil and planted.Extensive sampling of mine tailings,soils and alluvial sediments was performed,to detect asbestos contamination(XRPD,SEMEDS,TEM).Airborne asbestos was measured by environmental monitoring on polycarbonate filters(SEM and TEM),at the abandoned mines and at the closest centers.Huge amounts of chrysotile are still present in mine tailings(up to 20 wt.%),whereas soils and sediments were mostly below the 1000 ppm threshold;chrysotile is widespread almost in every part of the valley.Small amounts(<400 ppm)of asbestiform tremolite were detected.Airborne asbestos was below the PEL of 2ff/l for living environments,with some peaks at mine dumps and close to active serpentine quarries.This preliminary study provides useful tips and effective technical measures for risk reduction in the extractive context.展开更多
Resource extraction and nature conservation are often seen as opposing concepts.Traditionally,from the viewpoint of nature conservationists,they are only positively associated when rehabilitation efforts are made to r...Resource extraction and nature conservation are often seen as opposing concepts.Traditionally,from the viewpoint of nature conservationists,they are only positively associated when rehabilitation efforts are made to restore biodiversity in degraded lands due to extractive activities.Despite these conflicting relationships,in UNESCO Global Geoparks(UGGps),mining and quarrying can act as opening windows in the Earth’s surface exposing geoheritage.展开更多
文摘The application of the non-explosive expansion material （NEEM） is widely used as the controlled fracture method in quarry min- ing, especially in hard rocks. The pressure of NEEM is an important parameter in causing rock fracture. An empirical model based on hole spacing was developed to determine the pressure of NEEM in the rock fracture process. Primarily, the empirical model was developed by the mathematical method, utilizing dimensional analysis. Then, the Phase2 code, which is based on the finite element method, was utilized to predict crack growth in rocks. The results of numerical analysis show slight deviations from the empirical model. Hence, the polynomial re- gression analysis was used to modify the model. Finally, the modified model shows a good agreement with the results gained from numerical modeling.
文摘The I48TN is one of the 60 International Monitoring System (IMS) stations of the Comprehensive nuclear Test Ban Treaty Organization (CTBTO), characterized by its location in the heart of the IMS Infrasound network. The ability of the International Monitoring System (IMS) infrasound network to detect atmospheric nuclear explosions and other signals of interest is strongly dependent on station-specific ambient noise. This ambient noise, includes both incoherent wind noise and real coherent infrasonic waves. Infrasound analysis software detects tens to hundreds of events per day which consume a lot of time for the Infrasound analysts, to define and categorize events where around 90% of the detections are coherent noise. This study analyzed the importance of the synergy between infrasound and seismic data, and provided the infrasound data analyst with the most important local coherent infrasound sources in the region as recorded by the IMS station I48TN, in order to reduce the workload of the analysts and give them a clear view on the coherent noise affecting this station for better discrimination between events of interest like nuclear explosions and coherent sources. DTK_GPMCC and DIVA software were used to perform this study. Geotool software from the International Data Centre (IDC) was used in analysing seismic data from the Tunisian IMS station KEST. The result of this study allowed the characterization of the most important coherent local infrasound sources (Mines and Quarries) which are considered as coherent noise to I48TN station and correct parameters in some reference events in the Reference Event Database source of the International Data Centre.
文摘The Valmalenco area(central Alps,northern Italy)is well-known for the widespread mining and quarrying activities.Serpentinites are extracted and processed as valuable dimension stone in open-cast quarries,and a big underground mine provides talc as industrial mineral.The presence of long-fiber chrysotile veins,especially in the eastern part of the valley,gave rise in the past to widespread mining activity,particularly between the end of the XIX century and 1975,leaving huge amounts of mining waste and tailings.In recent times,part of the tailings have been stabilized and reclaimed,covered with soil and planted.Extensive sampling of mine tailings,soils and alluvial sediments was performed,to detect asbestos contamination(XRPD,SEMEDS,TEM).Airborne asbestos was measured by environmental monitoring on polycarbonate filters(SEM and TEM),at the abandoned mines and at the closest centers.Huge amounts of chrysotile are still present in mine tailings(up to 20 wt.%),whereas soils and sediments were mostly below the 1000 ppm threshold;chrysotile is widespread almost in every part of the valley.Small amounts(<400 ppm)of asbestiform tremolite were detected.Airborne asbestos was below the PEL of 2ff/l for living environments,with some peaks at mine dumps and close to active serpentine quarries.This preliminary study provides useful tips and effective technical measures for risk reduction in the extractive context.
基金supported by Portuguese national funding awarded by FCT—Foundation for Science and Technology,I.P.,projects UIDB/04683/2020 and UIDP/04683/2020a grant from the Palaeontology,Geoheritage and Applications European Master Program(Erasmus+Programme of the European Union)conceded to the first author。
文摘Resource extraction and nature conservation are often seen as opposing concepts.Traditionally,from the viewpoint of nature conservationists,they are only positively associated when rehabilitation efforts are made to restore biodiversity in degraded lands due to extractive activities.Despite these conflicting relationships,in UNESCO Global Geoparks(UGGps),mining and quarrying can act as opening windows in the Earth’s surface exposing geoheritage.
