|
Abstract The static and quasi-dynamic tests on granite specimens under various strain rates are conducted by using rock dynamic loading system. The specimens are 50 mm in diameter，with the length of 50，75，100，125 mm，respectively. The research results are drawn as follows：(1) Specimen strength is significantly dependent on strain rates and increases with the growth of strain rates with a power relationship. (2) Under static and quasi-dynamic loading conditions，rock strength generally decreases with the increase in specimen length. (3) When the diameter of specimen is 50 mm，the aspect ratio should be not smaller than 2；then steady test results can be obtained under different strain rates. (4) Peak strain under each strain rate decreases with increasing specimen size. (5) Both of secant modulus E50 and elastic modulus Et increase with increasing specimen size；and Et is larger than E50. (6) Failure mode is significantly dependent on strain rates and failure is serious when the strain rate increases. When strain rate ＜10－3 s－1，failure mode has a process of split failure-taper failure-shear failure；when strain rate ＞10－2 s－1，the failure mode changes from taper failure to shear failure directly.
|
|
Received: 04 October 2012
|
|
|
|
2013, Vol. 32 
