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The sections of the Andizhan concrete buttress dam are separated by contraction joints into elements: I, the upstream head; II, the buttresses; and III, the downstream head [i]. The buttresses of the channel and floodplain sections are separated by an additional joint to a height of 17 m (Fig. i).The contraction joints have a different design over the height.In the foundation zone they are made expanded --to be concreted; higher they pass into vertical and inclined contact joints --to be grouted (Fig. 2); farther the joints have the form of steps 3 m high and 1 m wide. The joints close on the downstream face of the dam. Horizontal keyways, trapezoidal in cross section with a spacing of 1-2 m are provided for in all joints except the closing joints.Deformation joints pass between the upstream heads and along the diaphragm.In addition to these main joints the dam has a number of secondary joints: along the contacts with the poured and keyway concrete in the zone of the conduits, in the plugs of the bottom outlets, in the seals of tectonic zones, etc. To provide normal static work of the dam, the contact joints were grouted. The deformation joints were grouted to impart to the structure the necessary rigidity under the effect of seismic loads. The cavities behind the metal lining of the conduits were also grouted to provide its interaction with the concrete; as were the cavities behind the formwork reinforced panels performing the function of a facing on the outer faces of the dam. The fractured concrete of the structure was sealed by the grout injection method.The joints to be grouted are separated by metal waterbars into segments with an average height of ii m and area of 47 m 2. The stepped joints have an area of 20 m = and the closing joints 84 m 2. The segments are located at different levels and do not form the usual grouting levels owing to the nonuniform construction of the dam sections.Twofold grouting was stipulated in each segment. Horizontal linear outlets (disk-valve outlets were used in the foundation zone of sections 15-27) arranged every 1-2 m and connected by metal pipes with a diameter of 25-32 mm were laid in the joints for primary grouting;i for secondary grouting --horizontal feeder pipes with a diameter of 20-25 mm with valve outlets of various designs.The grouting outlets were connected into the systems according to a loop scheme with two or three feeders. An air-outlet keyway common for both systems was constructed in the upper part of the segment.Mainly precast reinforced-concrete formwork (80%), which became a part of the structure, was used when concreting the dam.The grouting accessories were placed inthe formwork reinforced panels during their manufacture in the yard of the reinforced-concrete products plant. ThE pipes of the grouting systems were coupled by sleeves or welding in the blocks being concrete* and extended into the intersectional cavities of the sections to special metal platforms.