HYDRAULICS. ENGINEERING HYDROLOGY. HYDRAULIC ENGINEERING

Analysis of the stress-strain state of New Exchequer combined damat static loads

Vestnik MGSU 2/2015
  • Sainov Mikhail Petrovich - Moscow State University of Civil Engineering (MGSU) Candidate of Technical Sciences, Associate Professor, Department of Hydraulic Engineering, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Fedotov Aleksandr Aleksandrovich - Moscow State University of Civil Engineering (MGSU) student, Institute of Hydraulic and Power Engineering, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 141-152

In the article the authors analyze numerical modeling results of the stress-strain state of a combined dam created by construction of a higher rockfill dam with a reinforced concrete face behind the downstream face of the concrete dam. The analysis was conducted on the example of the design of 150 meter high New Exchequer dam (USA). Numerical modeling was conducted with consideration of non-linearity of soils deformation as well as non-linear behavior of the interaction “concrete - soil”, “concrete - concrete”. The analysis showed that though in a combined dam the concrete part gets additional displacements and settlements, its stress state remains favorable without appearance of tensile stresses and opening of the contact “concrete - rock”. This is explained by the fact that on the top the concrete dam is weightened by the reservoir hydrostatic pressure. The role of rockfill lateral pressure on the concrete dam stress state is small. There may be expected sliding of soil in relation to the concrete dam downstream face due to the loss of its shear strength. Besides, decompaction of the contact "soil - concrete" may occur, as earthfill will have considerable displacements in the direction from the concrete dam. Due to this fact the loads from the earthfill weight do not actually transfer to the concrete dam. The most critical zone in the combined dam is the interface of the reinforced concrete face with the concrete dam. Under the action of the hydrostatic pressure the earth-fill under the face will have considerable settlements and displacements, because soil slides in relation to the concrete dam downstream face. This results in considerable openings (10 cm) and shear displacements (50 сm) in the perimeter joint. The results of the numerical modeling are confirmed by the presence of seepage in New Exchequer dam, which led to the necessity of its repair. Large displacements do not allow using traditional sealing like copper water stops in the perimeter joint of combined dams. The sealing should be made of geo-membrane with placement of an asphalt pad under the face. Due to bending deformations in the lower part of the reinforced concrete face considerable tensile forces may occur. It is recommended to arrange a transverse joint in this part of the face.

DOI: 10.22227/1997-0935.2015.2.141-152

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