The impact toughness and the uneven extent of destroyed sample are the practical indexes of impact properties of frozen clay. The impact penetrant specific energy of frozen soil indicates the work of chiseling the frozen soil per unit volume

and reflects the ability to impact frozen soil. The frozen clay of the certain frozen shaft is regarded as the experimental soil sample. The impact experiments of frozen clay are made in order to measure these indexes in different temperatures and different impact energies. The impact penetrant specific energy experiment of frozen soil is conducted with the chiseling tool. Through analyzing the test results

it is shown that the impact toughness of frozen clay will increase with temperature decreasing and the impact energy increasing

and the uneven extent of sample may increase with the temperature decreasing

and the range of unevenness in the plane is ±3mm or so. With the decrease of temperature the hardness of frozen soil is bigger and bigger

the chiseling depth is more and more shallow

the drilling extent is more and more difficult. The relation formula between impact toughness and impact penetrant specific energy of frozen clay has been regressed. The impact toughness of frozen clay has a good relation to impact penetrant specific energy. The impact penetrant specific energy of frozen soil could be estimated by measuring its impact toughness.