University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Gregor Klambauer
(2015):
Seismic wave attenuation in a partially saturated sand-filled fracture.
Master / Diploma Thesis - Institut für Geotechnik (IGT),
BOKU-Universität für Bodenkultur,
pp 109.
UB BOKU
obvsg
- Abstract:
- Research on the seismic behaviour of rock material has been carried out since the 1950s while many important works dated back around 1980 and 1990. Recent improvements of the Split-Hopkinson Pressure Bar (SHPB) test method make it an attractive and also financially interesting instrument to investigate the seismic response of rock materials. The dynamic properties of rock joints have large influence on a number of sciences and engineering disciplines like mining, geoscience, seismology, earthquake and petroleum engineering. In this thesis, some relevant literature from several decades about experimental techniques and earlier findings in the research field is reviewed and their relevance is discussed the first part of this thesis. The second part of the work consists of experimental studies on wave propagation through rock joints filled with material of various degrees of water saturation on a modified Split-Hopkinson Pressure Bar at the Rock Mechanics Laboratory at the École Polytéchique Fédérale de Lausanne (EPFL). The six test series are carried out using granitic rock bars as the impact, incident and transmitter bars. Homogenous sand with different mass water content is used to simulate filled natural rock joints. The pressure bars are equipped with strain gauges and are connected to a LabView™ platform for signal recording. A wave separation technique for short bars is applied on the recorded signals to obtain the positive and negative waves which propagate through the bars during test. The simple and the normalised fracture transmission coefficient and the normalised specific fracture stiffness are calculated and are used to interpret the test results. The analysis of conducted tests shows that the joint mass water content has a significant effect on the wave transmission coefficients and the stress-closure relations of the filled rock joints.
- Beurteilende(r): Wu Wei