In the earthwork construction, if the soil is turned loose with a spreader first and then bulldozed, shoveled or loaded, the productivity can be significantly improved, the construction cost can be reduced and the construction safety can be improved. According to concerned data introduction, below same construction condition, use loosen soil implement to participate in construction, can make construction cost reduces 50%. It is better to use the loose soil tool in excavation than drilling and blasting.

According to the Soviet data, in the construction of the tnk-surgut railway, the productivity of drilling blasting operation was 31.6m3 /h, while the productivity of working with the loggers was 265m3 /h. Soil looseness determination: we can use the soil can be used to work the soil as looseness soil. The looseness of soil is determined by the propagation velocity of elastic wave in soil. Generally speaking, soil with elastic wave velocity of 2.5~3km/s is capable of loosening, which can be done by using a loosening tool.

To determine the propagation velocity of elastic wave, only a geophone is set up on the surface of the loose soil and a steel plate is stabilized at different distances from the geophone. The speed V of the elastic wave can be determined by striking the steel plate with a hammer until the time when the detector receives the detection signal "can be read directly from the instrument panel".