Study of operating modes of crane-drilling machines in thawed soils

The article deals with the problem of using crane-boring machines in the construction of communication lines and power transmission lines, the installation of fence posts and road signs, as well as in the construction of reclamation facilities. The data of experimental studies of these machines in the field to determine the rational modes of their operation in thawed soils are given. As a result of the research, it was found that the analysis of previous studies of the drilling modes of thawed soils does not give a clear idea of the existence and location on the response surface of the area of optimum drilling speed, taken as an optimization parameter. The necessity of researches is emphasized from the description of the area of the response surface by the polynomial of the first degree with the subsequent movement along its surface in the direction of the gradient of the linear approximation. The data of the results of experiments when drilling compacted loam with a drilling tool are given. It is concluded that it is more expedient to drill thawed soils at high rotational frequencies of the drilling tool and feed forces in the range of 1200 – 1700 kgf. The increased rotational speed of the drilling tool also provides the best conditions for transporting destroyed soil from the bottom of wells