Transformation structure and method of dam foundation draining hole of dam of hydroelectric station

The invention discloses a transformation structure and method of a dam foundation draining hole of a dam of a hydroelectric station. The transformation method of the dam foundation draining hole of the dam of the hydroelectric station comprises the following steps that (1) the foundation uplift pressure at the position of the dam foundation draining hole is measured; (2) when the foundation upliftpressure is larger than a design value, a groove is carved in original concrete in the axial direction of an original horizontal draining pipe, and the original horizontal draining pipe is disassembled; (3) backfilling is conducted on the carved groove with cement mortar, plastering is conducted on the two sides and the bottom of the groove with cement mortar, and a drainage ditch is formed; (4)hole bottom cleaning treatment is conducted on the original draining hole; (5) an auxiliary draining hole is additionally arranged at the position where the foundation uplift pressure is larger than adesigned value, a t-branch