The article presents the calculation of the stress-strain state of an earthen dam on a loess base on a computer. The calculation of the joint operation of the dam with the foundation was carried out using finite difference methods using shifted approximating grids (displacements and velocities are determined at the nodes of one mesh; deformations and stresses at the nodes on the other). The use of the developed algorithm, on the one hand, and the improvement of the mathematical model of the soil, based on experimental studies of samples for expansion, on the other hand, make it possible to assess the formation of trenches by calculation methods. The obtained calculation results are compared with the data of experimental model studies of the stress-strain state of an earthen dam with a subsidence base on a centrifuge. The correctness of the previously stated position was confirmed that for calculations of crack formation, the values of the limiting extensibility of the soil should be taken. It is necessary to determine these values by simulating the complex stress state of soil samples in laboratories. The areas of the dam have been identified as potentially the most in terms of cracking (a ridge zone with low compressive loads, close to uniaxial expansion in terms of operating conditions, and near-edge buried in places of a sharp break in the slope of the banks with significant stresses and destruction of soil material in a complex stress state by tension with sliding).