Condition of the concrete dam of the Toktogul hydroelectric station according to on-site observation data

Conclusions

• 1. The general condition of the dam meets the requirements determined by the criteria of safe and reliable operation. The dam is in a satisfactory state. The increase, compared with the design, of tensile stresses on the faces caused by deviation of the temperature regime of the concrete does not pose a danger for the structure.

• 2. The absence of substantial disturbances of the solidity of the structure indicates a high level of observance of the specifications when constructing the dam and substantiation of the adopted sizes of the concreting blocks, and also the effectiveness of the cooling and monitoring means being used.

• 3. The grout curtain, consolidation grouting of the foundation, and developed drainage system under the dam and in the wall abutments of the foundation at the heads attained on the structure provide effective reduction of the seepage heads in the foundation and absence of escape of the seepage flow onto the canyon walls near the downstream face.

• 4. The settlements of the dam, which at present have relatively stabilized, are less than the calculated in absolute value. Slowing of the increase of settlements is noted during filling of the reservoir compared with the predicted settlements from the weight of the dam, which is related to uplifting of the rock mass in the upper pool; a rise of the foundation was recorded in the lower pool; the tilt of the dam toward the lower pool is 0.01%.

• 5. Opening of the joints in the dam is not undergoing changes, on the whole the process of deformation of the joints after grouting has stabilized.