水岩和冻融作用下岩石的脆性评价OACSTPCD

On the basis of summarizing current methods for evaluating rock brittleness and discussing the advantages and disadvantages of each method a new calculation method for the brittleness evaluation of rock is proposed by considering the stress-strain curve and energy evolution law of rocks.The proposed new brittleness evaluation method is verified by the triaxial test results of the red bed soft rock under water-rock action and natural condition and the sandstone under natural condition and freezing-thawing action.The results show that the new brittleness index decreases with the increase of confining pressure regardless of the natural state or water-rock interaction and the rock mass's brittleness under water-rock interaction is weaker than that under natural conditions with an average reduction of approximately 44%under various confining pressures.In addition the brittleness of rocks decreases with the increase of confining pressure under both natural and freezing-thawing conditions and the brittleness of sandstone under freezing-thawing is lower than that under natural conditions with an average reduction of approximately 13%under different confining pressures.