Investigation of the opening of construction joints in an experimental section of the Andizhansk dam (Uzbek SSR)

Abstract

1. In the rock zone the opening of the joints agrees with the calculated value of the temperature deformations of adjacent blocks only during the initial period. Subsequently, the opening of the joints is greatly affected by the embedment of the blocks in the foundation and by the temperature regimen of the latter. Thus, for the period of maximum joint opening, the coefficient which takes into consideration the embedment in the foundation and its temperature regimen was equal to 0.42, while for the entire cooling period it was equal to 0.34. 2. The initiation of joint openings between the sections coincides with the time of disappearance of compressible stresses in them. 3. Opening of the joints takes place uniformly in the horizontal sections (with an accuracy of up to 10%), independently of the temperature drop in the structures which make up the joint. 4. The presence of friction forces in the horizontal areas of stepped joints causes some reduction of the opening of such joints between the vertical faces (up to 10%), as compared with a plane joint, as well as cracking of the steps on the side of the head blocks and on the side of the buttress blocks.