|
Abstract For the purpose of researching the damage characteristic of rock porous structure under the condition of freezing-thawing cycles，taking the granite as the samples，3 times freezing-thawing cycles experiments with the freezing temperature of －40 ℃ and thawing temperature of 20 ℃ were conducted. The nuclear magnetic resonance(NMR) technique was used to test the rock samples；and the rock porosity，crosswise relaxation time T2 distribution and nuclear magnetic resonance imaging(NMRI) were obtained. The results show that T2 distribution of granite exhibits three peaks. Rock porosity，T2 distribution and T2 spectrum area increase with the freezing-thawing cycles. The variation ranges of them are different for every sample and it indicates that the characteristics of rock porous grow and expand under the condition of freezing-thawing cycles. Also，the microstructure distributions of porous have been visually shown by the NMRI；and the processes of rock damage under the condition of freezing-thawing cycles have been shown dynamically. The NMR characteristics of rock under the condition of freezing-thawing cycles has provided reliable experimental data for research of rock damage mechanism.
|
|
Received: 26 February 2012
|
|
|
|
2012, Vol. 31 
