In order to rais: the precision level of the mcasurment with the soil trough testing machine, the improvement of the frame structure of the system should be given priority. With the aid of a computer, the strength and rigidity of the frame structure of the machine were calculated. This article shows how a space problems was seperated into two coplanar problems, how both problems of plane grillage and plane frame were calculated, and how they were summed up. The results of the calculations agreed to what were exp cted.