The study on Size effect of fracture toughness of test of undisturbed frozen soils based on Gray theory

Based on the previous undisturbed frozen field test, the research and analysis on the Size effect of fracture toughness K_IC of vertical crack and herringbone crack of undisturbed frozen soils specimens of test I is performed emphatically, and it is found the rules that it varies with volume change. Meanwhile, a theoretical prediction by using the Gray System Theory methods is made and the theoretical prediction results K_IC has been gotten, which is compared with the results of the test and the error fits the accuracy requirement. Thus it has been made a meaningful exploration for the research method of Size effect of fracture toughness K_IC of test I of undisturbed frozen soils.