Sealing the joints of the Andizhan concrete dam

Conclusions

• 1. The methods of installing the embedded grouting accessories and the technology of grouting provided filling of the joints and cavities in the dam with grout, imparting to it the necessary rigidity and sufficient degree of solidity, which was confirmed by the data of on-site observations of the state of stress and strain of the structures. The effectiveness of secondary grouting carried out during construction of the structure was insignificant according to the data of the monitoring and measuring equipment.

• 2. Among the factors having a favorable effect on the results of grouting the joints are: the use of precast reinforced-concrete formwork, high rate of placing the concrete in the dam, and temporary closing of the hollows of the sections to stabilize the temperature regime of the concrete and to achieve a more uniform opening of the joints. The results were adversely affected by: a change to a stepped design of the joints; considerable (more than 16 m) difference in the height of adjacent elements of certain sections; poor effectiveness of cooling the concrete masonry; difficult access to high joints and organization of works on their grouting.

• 3. The ultrasonic method is the most informative method of checking the quality of grouting joints. Core drilling gives more visual results but is less economical.

• 4. In the dam sealing plan it is necessary to include the ways and means for sealing various cavities, contacts, and secondary joints.