A Basic Experimental Study of Earthquake Prediction in Terms of Radar Technology

To apply the radar technology in earthquake prediction, experiments of detecting the variation in the reflection radar wave intensity associated with loading of rock samples have been performed for 27 rock samples with different mechanical characters in the laboratory. The radar measuring instrument used was the special RSC system produced by HP Co., USA. Observation was made in four radar wavebands of 8mm, 2cm, 3cm and 5cm. The variation in the radar wave reflection intensity of the rock samples with the loading stress was measured automatically and continuously in the loading process. The experiment shows that there do exist variations in the reflection radar wave intensity which is closely related to the microwave reflection characteristics of the subject in the loading phase and unloading phase for all samples without exceptions, with only differences in the quantity and trends of the variations for different samples or at different wave band and different polarization modes. The relative variation of the reflection radar wave intensity for most of rock samples is a few percent to more than ten percent, and the maximum variation of the granite (No.113 sample) even reaches 20.2% and that of the sandstone (No.212 sample) reaches 27.9% as the biggest two in the experiments. The experimental results would provide an experimental evidence and physical basis for applying the radar technique in the earthquake prediction and in the monitoring and assessment of stability for rock masses engineering.