Evaluation of the condition of the gravity dam of the Kurpsai hydroelectric station during operation

Abstract

on revegetation of the territory of the spoil bank with hydraulic filling of the toe drains according to the results of calculations in 7 years and in the absence of toe drains, 34 years.For an experimental field check of the new special technology of hydraulic fillings and for refining the characteristics of the deformability of the material of the core zone of the Berezovyi Log spoil bank was carried out in a section with a thickness of the hydraulic-filled clay-chalk rocks of more than 45 m. The geometric parameters of the toe drain: length 500 m, width 70 m, maximum height above the surface of the core zone 3 m, penetration of the sands into the unconsolidated stratum up to 22.5 m. Hydraulic filling of the toe drain was carried out by the pioneer method from the ends without a trestle. The experiment made it possible to improve the technology of hydraulic filling of the draining elements in the stratum of finely divided, saturated rocks (Fig. 2). Sounding of the 45-m-thick core zone showed an identity of the calculated and actual values of the degree of consolidation of the hydraulic-filled stratum. Hydraulic filling of the sand bed began immediately after filling the spoil bank in the northern part to the design level, since the sand bed, working as a porous plate, accelerates consolidation of the core zone of the spoil bank. Hydraulic filling of the sand bed was carried out by the trestle-free method as a 3-m layer with 1.5-m embedment into the core zone. In accordance with the revegetation project of the spoil bank territory, a loam layer l-m thick was hydraulically filled on the sand bed. For revegetation of the spoil bank it is required to place a large amount of chernozem (4 million m3). In 1983 chernozem was placed for the first time by the hydraulicking method on an area of I00 ha (154,000 m 3 was placed).