Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Prefailure Behaviour of Rock at Rockburst Hazard Areas: Laboratory Investigations on Microacoustic Emissions
Rockbursts are mainly induced by mining activity and result in the emission of seismic signals transmitted through the rock. Up to now, the monitoring of mining regions to detect stress changes and stress accumulations in rock uses incidences of occurrence and intensities of seismic events that occur due to mining activity. Within this research work, the occurring frequencies of microacoustic events are determined and analysed to find indicators for the approaching macroscopic failure of rock. The first part of this work treats extensively the basics of rockbursts, fracture mechanisms and acoustic emissions. It becomes obvious that measuring techniques can already give information about stress changes and stress accumulations in rock with the help of incidences of occurrence and intensities of microacoustic events. A prediction of the time of approaching rockbursts is yet not possible. The main focus of this research work is, therefore, the complement investigations of the frequency behaviour of microacoustic events of rock. To investigate the stress changes inside the material, uniaxial compression tests are carried out and the microacoustic events that are generated by the load application are especially analysed in the phase of prefailure in which already existing microcracks inside the specimen grow, interact and coalesce until the specimen fails macroscopically. The carried out laboratory tests are mainly investigated by analysing the frequency behaviour of the microacoustic events. It is presented that the frequencies change during load application. Hence, recorded signals and their spectra can be assigned to their state of fracture and their state of loading by investigating the frequencies of signal spectra of the microacoustic events. With these first investigations of their kind, specific indicators are found to identify the present state of fracture and loading.
Prefailure Behaviour of Rock at Rockburst Hazard Areas: Laboratory Investigations on Microacoustic Emissions
Rockbursts are mainly induced by mining activity and result in the emission of seismic signals transmitted through the rock. Up to now, the monitoring of mining regions to detect stress changes and stress accumulations in rock uses incidences of occurrence and intensities of seismic events that occur due to mining activity. Within this research work, the occurring frequencies of microacoustic events are determined and analysed to find indicators for the approaching macroscopic failure of rock. The first part of this work treats extensively the basics of rockbursts, fracture mechanisms and acoustic emissions. It becomes obvious that measuring techniques can already give information about stress changes and stress accumulations in rock with the help of incidences of occurrence and intensities of microacoustic events. A prediction of the time of approaching rockbursts is yet not possible. The main focus of this research work is, therefore, the complement investigations of the frequency behaviour of microacoustic events of rock. To investigate the stress changes inside the material, uniaxial compression tests are carried out and the microacoustic events that are generated by the load application are especially analysed in the phase of prefailure in which already existing microcracks inside the specimen grow, interact and coalesce until the specimen fails macroscopically. The carried out laboratory tests are mainly investigated by analysing the frequency behaviour of the microacoustic events. It is presented that the frequencies change during load application. Hence, recorded signals and their spectra can be assigned to their state of fracture and their state of loading by investigating the frequencies of signal spectra of the microacoustic events. With these first investigations of their kind, specific indicators are found to identify the present state of fracture and loading.
Prefailure Behaviour of Rock at Rockburst Hazard Areas: Laboratory Investigations on Microacoustic Emissions
Vorbruchverhalten von Gesteinen in gebirgsschlaggefährdeten Gebieten: Laboruntersuchungen von mikroakustischen Emissionen
Kimme, Nadine (Autor:in) / Universitätsbibliothek Braunschweig (Gastgebende Institution) / Stahlmann, Joachim (Akademische:r Betreuer:in)
2009
Sonstige
Elektronische Ressource
Englisch
DDC:
624
| UB Braunschweig | 2009
| UB Braunschweig | 2009