Stress state of an earth dam under main loads considering data from field observations

Reliable and safe operation of hydro-technical structures (earth dams), in the seismic regions of the republic, requires researchers to constantly improve the calculation methods in accordance with the requirements of regulatory documents for basic and special combinations of loads, including seismic ones. A calculation method is proposed for estimating the stress state on the example of an earth dam of the Charvak HPP (in operation for 47 years) in a plane elastic statement under main loads, taking into account the real piecewise-inhomogeneous physical and mechanical characteristics of soil of the structure body. Individual results of solving the problem were compared with the data of long-term field observations. The calculation method allows determining the kinematic characteristics (displacements, settlements, stresses, pore pressure) of an earth dam, which makes it possible to predict the state of the most vulnerable places in the structure and, if necessary, to develop appropriate measures to strengthen them. The problem was solved by the numerical finite element method. According to the developed technique, the problem by the numerical finite element method was reduced to solving a system of linear equations relative to the desired displacements. The calculation results are presented in the form of isolines of the stress-strain state of the dam body under the main loads (gravitational forces, hydrostatics). The numerical results of solving the problem and their comparison with the data of field observations make it possible to determine the reliability of the developed methods and software and thereby determine the vulnerable zones of the earth dam, where the loss of stable operation of the structure is possible. Based on the research results, appropriate recommendations were made. (paper)