When performing the objects on the distant locations, it is necessary to make the foundation structure with as little ground impact as possible. One of the usual choices is the rigid steel grid construction on the shallow foundations. Many authors worked on the problem of defining calculation expression for the soil reaction coefficient, which represents the behaviour of the ground. In the programmatically solution called SE_Calc values of the soil reaction coefficient are calculated by each author. The paper shows the effects of different modelling of the soil reaction coefficient on the steel grid structure, rigid or soft. The structural response and the contact with the soil are analysed.