The concrete dam of the Krasnoyarsk hydroelectric project has a triangular profile with a vertical upstream face and an inclined downstream face with slopes of 1:0.8 (in the spillway section) and 1:0.76 (in the power station section). The dam is 124 m high. Deformation joints are spaced every 15 m; the sections are divided into columns with a lateral dimension of 11.5 m [1].The dam foundation consists of strong, jointed granite. The modulus of deformation of the rock mass, determined by subjecting a rigid plate to a vertical load, is equal to: a) sparsely jointed rock E = 1.6 X l0 s kg/cm z b) medium-jointed rock E = 0.9 X 10 s kg/cm z c) highly jointed rock E = 0.45 X 10 s kg/cm z Shear tests on "chunks" from relatively weaker fissured rocks indicated that the rock has a modulus of deformation* of (0.50-0.62) X l0 s kg/cm z.Concrete Mix. The body of the dam consists basically of concrete of the following grades: M200, B-8 (lower portion of the upstream face) and M250, Msp-300. The concretes were prepared from normal-heat cements from the Krasnoyarsk cement plant. The consumption of slag Portland cement was 230-240 kg/m s for M200 concrete and 280-310 kg/m s for M250 concrete. The Krasnoyarsk cements, manufactured in accordance with the technical specifications of the Kramoyarskgesstroi, are of the normal-heat variety as revealed by their use, yield good hydrotechnical concrete conforming to the specifications laid down by GOST 4795-67, greatly facilitate temperature regulation, and fulfiU the conditions of remaining monolithic during severe winter weather.
The opening of the contact joint between the concrete and rock in the zone of the upstream face of the bed sections of the Sayano-Shushenskoe dam, which was noted during the filling of the reservoir, continues to increase ( Fig. 1, data obtained by the Hydraulic Structures Laboratory at the Sayano-Shushenskoe hydroelectric plant). The maximum joint opening was observed in sections 18 and 45, which are located near the shoreline slope, and the minimum opening in key section 33. Variations in the opening of the contact joint for all sections, excluding section 33, have a clearly expressed seasonal character.Basic factors governing the opening of the contact joint in high gravity dams are rather well understood [1][2][3][4]. A tension zone may be forming beneath the upstream face of the dam as a result of load action on the structure and its rock bed. Tensile stresses a x virtually always develop along vertical platforms, while stresses cry develop along horizontal platforms only under certain conditions. The tensile stresses ay do not develop when they are completely compensated by the vertical component of the active loads, or when an additional store of compression is released at the contact by special measures taken during the dam's construction [5].The stage construction and monolithizing of the structure during the annual rise in the headrace level exert a significant influence on the stress--strain state of the concrete-rock contact of an arch-gravity dam.Computational and model studies conducted at the V. E. Vedeneev All-Union Scientific-Research Institute of Hydraulic Engineering with consideration of the actual stage construction of the Sayano-Shushenskoe Dam predict the development of tensile stresses of up to 2 MPa in the rock bed in the zone of the upstream face of the channel sections as the reservoir is filled to the normal operating level. Monolithizing of the Sayano-Shushenskoe Dam during its construction was carried out annually with seasonal drawdown of the reservoir in the winter-spring period with rather accurate observance of design requirements regarding the temperature state of the concrete masses; this ensured the combined action of the dam's columns. The behavior of the grouted intercolumn and intersectional joints, the character of variation of the relative deformations, as measured in the monolithic concrete and in the section of concrete with the joint [6], the displacements of the structure, and the deformations (bed settlements and tilting of the dam) suggest the monolithic character of the Sayano-Shushenskoe Dam~The monolithizing that was carried out has caused, among other things, "bridging" of the dam on the shoreline slopes and the appearance of an additional retaining moment, which prevent the tilting and deflection of the dam's channel sections. Neither of these factors make it possible to trace the sections freely beyond the depressions of the reservoir channel, which are caused by increasing pressure on its water column with increasing headrace level and which are developed by ...
To simplify works on restoration of the roller tracks of the main fixed-axle gates of the culverts when they are worn and to reduce expenditures, the design of the roller tracks was fundamentally changed, Instead of the embedded cast tracks, rolled plates in which removab%e forged bushings are fastened are used (Fig. 4), The operation of repair of the roller tracks amounts to replacing the worn bushings with new ones A fundamentally new scheme of automatic control of locking based on the use of noncontact logic elements was developed for the first time in the design of the Cheboksary lock. The main component in this scheme is a logic machine controlling locking, which has a number of substantial advantages compared to the relay scheme:high degree of reliability providing continuous 24-h operation during the navigation season; the logic elements composing the machine have a practically unlimited service life (guaranteed life, 12 years); high noise stability; simplicity of maintenance; low cost.The logic machine controlling locking performs the following operations: a) reception of information arriving from the dispatcher's control board and formation of a system of instructions controlling the operation of the actuating mechanisms in conformity with algorithm for the technological process of locking; b) reception and storage of information arriving from external sensors monitoring the operation of the actuating mechanism of the lock (degree of filling of the lock chambers, position of the gates, etc.); c) control and monitoring of the operation of the light signals; d) protection of the mechanisms and devices of the lock from accidents and prevention of emergency situations.The introduction of the aforementioned designs aimed at increasing the reliability and improving the operating conditions of the lock effect also a considerable saving. The plan of construction work calls for a stepped scheme of constructing the SayanoShushenskoe dam with offsetting of the downstream face with differences of heights between columns as much as 35-55 m. Construction of the dam is accompanied by filling of the reservoirs which necessitates its annual stage-by-stage sealing by grouting the joints between the columns and sections.A grouting temperature of +2-7~ is achieved by pipe cooling of the concrete.The spacing of the pipe coils is 1.5 x 1.5 m.The bulk of the works on sealing the dam, with consideration of its state of stress, should be performed in the winter--spring period during seasonal drawdown of the reservoir. Grouting works at a concrete temperature below 0~ are not permitted by the existing technological regulations.However, the design characteristics of the dam and scheme of its construction and the climatic conditions of the construction region do not make it possible to completely eliminate freezing of the concrete,The vertical and horizontal surfaces are exposed to the effect of outside air temperature for a long time, in some cases up to 2-3 years.This leads to the penetration of the frozen zone of concrete to a d...
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