Discussion of construction specifications

Conclusions

• 1. At present there is a discrepancy between the specifications goveming the determination of seismic loads on concrete gravity and earth dams and the specifications governing the calculation of strength and stability of these dams in the case of a special combination of loads.

• 2. The use of the existing specifications for designing dams of the types considered hampers an engineering interpretation of the results of calculating their seismic stability and economic designing of class I dams in regions with scale 9 earthquakes.

• 3. In order to coordinate the specifications goveming the design of dams, particularly the requirements imposed on them in the case of a special combination of loads, it is necessary to introduce refined strength and stability criteria based on consideration of the dynamic behavior of the foundation-structure-reservoir system and on consideration of the potentiality of the concrete to absorb considerable tensile stresses during brief loads and to perform its functions in the presence of cracks.

• 4. To develop these criteria it is necessary to carry out full-scale, model, and analytical investigations to establish the limiting states of hydraulic structures of various types and to determine their quantitative characteristics, which can serve for evaluating the permissibility of various types of residual deformations for different types of structures.