ALBERT

Notizen: Conclusions 1. The method proposed here for dividing a structure into blocks by means of precast separating elements successfully solves the problem of reducing the high temperature stresses in the concrete during the construction period and permits carrying out the concreting operations in a continuous manner on the entire width of the structure, from the upstream to the downstream ends. 2. When this method is used, a) the systematic placement of the concrete mix in a large portion of the structure is assured; b) the necessity to place high blocks is eliminated, and the temperature regimen is thus more uniform; c) the static action of the structure is improved, and the transfer of the shearing forces is assured, even if no grouting is applied; d) the importance of the grouting work is lessened because of the considerable simplification of the required grouting installations; in many cases the grouting may be applied only partially; d) there is the possibility of widely using special equipment for leveling and compacting the concrete. 3. The economy of the method proposed here is governed by the increased mechanization of the concrete placing work, by the greater reliability of the structure, and also by the possibility, in this connection, of reducing the length of the dam.

Notizen: Conclusions 1. The downstream regimen of freezing and the volume of the river flow exert a decisive effect on the magnitude of the backwater due to ice, ΔH3. For a given length of the unfrozen patch, the quantity ΔH3 is directly proportional to the duration of the ice-drift period downstream, and to the magnitude of the discharges through the plant during that period. 2. The sharp increase of discharges through the plant, after Sundays, at the beginning of the winter period, as the ice edge approaches the plant, in combination with an unstable regimen of the air temperatures, results in artificial ice drift, ice jams, higher roughness coefficients of the lower surface of the ice, and higher values of ΔH3. 3. During the period of stabilization of the ice edge, under negative air temperatures, the nonuniformity and magnitude of the discharges through the plant do not exert an unfavorable influence on the ice regime downstream.

Notizen: Conclusions 1. In the case of a limited content of sand in tailings (〈30%) hydraulic filling of a tailings dump with the formation of a sand beach of sufficient length is possible, provided that the maximum bulk density of the hydraulic mixture is not exceeded (not above≥70% sand deposition for the investigated tailings dumps). 2. The results obtained are applicable under conditions similar to those which were investigated and can be used in the case of hydraulic filling of earth.

Notizen: Conclusions 1. The device for cooling coarse aggregate in hoppers, designed by the Leningrad branch of Orgénergostroi, cools gravel of all fractions to an average temperature of 4–5°C at a temperature of the cooling air of −3°C. At a temperature of the cooling air from −6 to −8°C, the gravel is cooled to 0 to −2°C. 2. The degree of cooling of the material is easily regulated by changing the rate of air flow. The gravel is cooled uniformly, and freezing together of the pure material is not observed during continuous plant operation. To prevent freezing then the plant is shut down for more than 20–30 min, and the delivery of cooling air must be discontinued. 3. Cooling of sand was ineffective for a number of reasons, the main ones being the large aerodynamic resistance and improper design of the hoppers, which determined the character of sand discharge. 4. To calculate the heat-transfer coefficient when designing such devices, it is recommended that B. I. Kitaev’s formula be used with the introduction of our correction factors.

Notizen: Conclusions 1. The rise in water levelΔHW 1 during freezing is affected by the meteorological conditions (air temperature), stream velocity, and filling of the channel during the period prior to stable ice formation. At the same time, the lower the air temperature the smaller is the effect of capacity of the river (within the limits considered) on theΔHW 1 and βb 1, values (Fig. 2). 2. The relationships obtained provide a forecast of theΔHW 1 and βb 1 values, as a function of the anticipated air temperatures and planned station discharges. 3. When selecting limits to the winter performance of a hydroelectric station, it is necessary to take into account the meteorological situation during freezing of the river. If stable low temperatures are forecast, the restrictive requirements may be reduced in accordance with the curve (Fig. 2). 4. A sharp increase in the station discharges must be avoided if the edge of the ice is in the area of gaging station No. 1, in order to avoid the possibility of breakaway of the edge of the ice and the formation of artificial ice flows, resulting in blockages, and a rise in the level of the lower pool.

Notizen: Conclusions 1. The specific features of solid reinforced-concrete beam, slab, and wall structures of hydraulic engineering installations determine the special nature of fissuring occurring in them, manifested in spindle-shaped cracks with a network of secondary inclined cracks, frequently joining up with the spindle-shaped crack. The formation of this system of fissuring sometimes results in overstressing of the zone in compression and, with the operational loads, the rigidity of the structures diminishes, while the resistance of the structures to shearing forces evidently diminishes in the absence of transverse reinforcement. 2. In the case of some structures of hydraulic engineering installations, this type of fissuring is impermissible, since, under certain conditions, it lowers reliability and reduces the service life of the structures, particularly in the case of reversing and repetitive loads and with various types of aggressive media. 3. In order to prevent this type of fissuring or to reduce the harmful effect of spindle-shaped cracks, one of the most effective measures is distribution of the transverse reinforcement over the height of the section, in addition to supplementary anchoring of the reinforcing bars at the points of failure. In order to obtain the necessary strength of solid thick-walled structures with a small percentage of reinforcement in the presence of large shearing forces, design transverse reinforcement is necessary, as demonstrated by experïments on full-scale members. 4. The task of future investigations should be the investigation of more rational measures for increasing the percentage of reinforcement in hydraulic engineering structures, and at the same time improving their economics.

Notizen: Conclusions In ultrasonic tests of concrete quality in thick-walled structures (more than 0.5 m thick) and in massive blocks in hydraulic structures, it is necessary to take into account change in the amplitude-frequency spectra of ultrasound pulses with the path length in the concrete, which is a regular phenomenon associated with the normal absorbing properties of the concrete. This must be distinguished from the changes indicating quality deterioration or structural defects in the concrete. The quantitative decrease in the velocity of propagation of ultrasound along a ray in the direction of each sounding depends on the physicomechanical properties of the concrete, its composition, its age, and the natural frequency of the ultrasound-pulse emitter-transducer; for measurement bases between 1 and 6 m, it lies in the range 1–12%. Correction coefficients δ for assessing the effect of this factor can be found with sufficient accuracy for practical purposes from the measured acoustic characteristics of the concrete, in conjunction with the theoretical relation (13) or the graphs in Fig. 6.

Notizen: Conclusions 1. The grouping employed in the Chir-Yurtsk hydropower scheme, with its deeply submerged pressure outlet centrally located with respect to the reservoir, is very fortunate and enables the reservoir to be cleared of sediment deposits by sluicing. 2. The successful experimental sluicing of the reservoir shows that the hydraulic scouring of sediment deposits is technically possible and economically expedient; the cost of removing soil amounts to 0.5 to 1.5 kopecks/m3. 3. The hydraulic clearing of reservoirs should be carried out, having due regard for the interests of all branches of the national economy (power, agriculture, water supply, fish industry, etc.), in order to achieve the maximum national economy and its correct evaluation.

Notizen: Conclusions 1. Cement grouting of fissured ledge rocks leads to a marked reduction in slip deformation due to an inclined load. The effect of cementation is most marked in badly fractured rocks, the slip of which in the natural state is characterized by an elongated horizontal-displacement graph. 2. Cement grouting leads to an increase in the shear strength of hard rocks. Cementation is most effective in badly fractured rocks without fine earth filling, owing to the efficient filling of the cracks by the cement solution. (We must, however, remember that such conditions are not always found in natural rock masses.) 3. The use of cement solutions based on dispersed cement (colloidal cement or dry-vibromilled cement) permits cement grouting to be more effective than with ordinary cement. 4. The presence of badly broken sections in a rock foundation is not necessarily a reason for reduced slip resistance parameters or for removal of much of the rock, and in such cases we should always consider whether it is advantageous to use cement grouting to improve the quality of the rock.

Notizen: Conclusions 1. The development of overall scientific research in the USSR for the justification of design and construction of hydraulic engineering and hydropower installations is inextricably linked with bringing to life the Go\'elro plan in the field of hydropower and water supply, the five-year plans for the development of the economy, and subsequent large-scale plans for the multipurpose utilization of the water resources of the country. 2. Overall scientific research in the field of hydraulic engineering and hydropower brings out all aspects of the performance of future installations and the multiplicity of the phenomena and processes occurring. This type of research has enabled Soviet experts to resolve many problems in hydraulic engineering construction and to introduce new types of hydraulic installation on soft and rock foundations, employing advanced methods of organization and performance of construction, taking into account the special climatic conditions and unique nature of the installations. Overall investigations have resulted in advances in Soviet hydraulic engineering science with respect to a number of problems. On the basis of these investigations, big engineering advances have been made in Soviet hydraulic construction. 3. Large-scale overall investigations have brought about substantial savings in construction, amounting to 10% of the cost of a hydroscheme. 4. The work carried out throughout the country in the coordination of scientific work in the field of hydraulic engineering and hydropower has resulted in more effective and clear-cut organization of overall scientific research, as regards both extending the range of problems studied and the composition of the teams, and with respect to the time taken to complete the work and apply the results, and with respect to optimum utilization of the available key scientists and experts, research, stations, and their equipment. These facts are very important considering the scale of hydraulic engineering construction at present and in the future in the Soviet Union, for meeting the needs of all branches of the economy, including power, agriculture, industry, fisheries, transport, etc.

Notizen: Conclusions 1. The character of the (E1, σ1) curve, which is an equilateral hyperbola, makes it possible to determine: a) the integral value of the natural stresses in the rock mass over the foundation of the whole area beneath a plate; b) the relation between the deformation modulus, determined by the static method, and the dynamic modulus of elasticity. 2. Repeated loading of the foundation enables us to predict by an indirect method the approximate effect obtainable by cementing a particular sector of ledge rock.

Notizen: Conclusions The Sulak River and its tributaries constitute an extremely important hydropower resource of the Dagestan ASSR. The cascade of 20 hydroelectric plants on this river, which will have a total capacity of 3 million kW and an output of 10 billion kW-h (the Gergegil'sk, Chiryurtsk Nos. 1 and 2. Chirkeisk, and other projected plants), provides an excellent example of the effective utilization of a mountain river for the production of power.

Notizen: Conclusions and recommendations 1. In the case of permanently frozen fissured rock, the steep slopes of excavations must be faced with concrete as soon as possible after exposure. If the lag between exposure and concreting is too long, the sides of the excavations suffer severe damage, owing to thawing of the ice in the fissures. 2. Preparation of a permanently frozen foundation for placing concrete involves much labor, time, and electricity for heating. The question of heating permafrost rock (and the extent of this heating) is now of great importance and must be studied. 3. Concreting in small blocks reduces the possibility of fissure formation, but requires much labor (3–4 men per day per 1 m3 of concrete). The work involved in preparing the blocks constitutes 80–85% of the total concreting operations. 4. Winter concreting in a severe climate is characterized by a marked reduction of the pace of the work, a sharp increase in labor costs (by a factor of 2–2,5) and in overall costs (by 53%). 5. Since the very nature of hydraulic construction requires the placing of large amounts of concrete in winter, a comprehensive group of machines and equipment (special concrete transporters, cranes, buckets, etc.) must be developed to ensure efficient concreting at temperatures in the range from −45 to −55°C.

Notizen: Conclusions 1. The hydromechanical equipment of the upper and lower pools of the Plyavin'sk hydroelectric station on the whole reliably ensures the operation of the development under all conditions. 2. The single-sluice working and emergency gates deserve a favorable evaluation. 3. The grab beams require reconstruction, since they presently work unreliably. 4. Under operating conditions large expenditures are needed for maintaining the anticorrosion coatings of the equipment.

Notizen: Conclusions 1. The operating conditions recommended in the literature for hydraulic lifts in pressurized hydraulic transport systems are not usually the optimum. 2. The most suitable in respect of energy consumption is the dry charge conditions of the hydraulic lift, since the ratio of solid to liquid components must correspond to optimum consistency of the hydraulic mix in the pressure pulp line.

Notizen: Conclusions 1. It is highly convenient to excavate soils by excavators of 2–3-m3 bucket capacity and to remove those soils from the foundation pits in large dump trucks; the use of bulldozers and other equipment for these operations results in longer work periods and in slightly higher costs. 2. Compaction of soils in natural beds and backfills by C-629 hydrovibrators is 2–3 times more effective than surface vibration rolling or other methods. In this compaction method, large volumes of soil are placed in the entire excavated zone. As a result of the wide use of dynamic penetration testing, the geotechnical control process is simplified.

Notizen: Conclusions Alternating freezing and thawing has a much bigger effect on the variation in elastic, inelastic, and deformation characteristics of concrete during the test than impact. During the test for resistance to frost, the nature of variation of the dynamic Young's modulus, coefficient of internal friction, and permanent deformation is practically identical for concretes of the compositions investigated. In the case of impact, the increase in the γ and ε values is inversely proportional to the initial inelasticity of the concrete, and the relative reduction in E is approximately the same for the investigated concrete compositions.

Notizen: Conclusions 1. A concrete slab or rock mass, exposed to the action of a constant displacement force, statically stable against displacement, will be subjected to slow irreversible displacements under the action of temperature fluctuations. 2. When irreversible temperature shifts cannot be tolerated, connections must be included in the system so that the expansions and contractions occurring on account of temperature fluctuations are absorbed within the limits of elastic deformations. 3. At present, irreversible shifts are not included in programs of full-scale observations or geologic prospecting works. Such displacements, however, may be important in the overall set of conditions governing the performance of a hydraulic engineering installation or particular features of the geological structures. In some cases, determination of the possibility of irreversible shifts may assist in the correct interpretation of settlement and stress observations on structures. There is no doubt that movements similar to those described above are common in nature and can be observed frequently, if readings are taken with the necessary accuracy embracing a sufficient number of heating and cooling cycles on an investigated structure, natural rock feature, earth slope, etc.

Notizen: Conclusions 1. The conditions of operation of the transition zone at the upstream slope side of the dam's core, between its foundation and the minimum operating level, are more favorable than those at the downstream slope. There-fore, the design and grain-size selection methods for the transition zone for the dam's core section under consideration should be varied as applicable to any given conditions and not by analogy with the downstream core slope. 2. The heretofore indicated practical recommendations as to the upstream transition zone design and material selection would ensure strength and stability of the dam core. They are economically efficient.

Notizen: Conclusions For hydraulic-fill earth dams placed under water, it is extremely important to consider in advance all the factors capable of affecting their dynamic stability. Measures for compacting the soils should be undertaken during the construction period.

Notizen: Conclusions 1. The reconstruction of vertical asphalt seals in a dam, by replacing the defective heating elements by new ones, is an advisable measure, which proves to be cheaper and simpler than the installation of new seals. 2. Heating of the asphalt seals and their subsequent compaction, followed by placing of additional mastic, permit reducing considerably the seepage losses through the contraction joints of a dam. This, in turn, leads to reduction of the seepage losses through defective concrete in adjoining zones. 3. Higher effectiveness and lower cost of the operations required for controlling seepage losses through defective concrete in water-retaining structures may be achieved by adopting the drilling and grouting procedures described in this article. These procedures, which have proved to be effective after many years of successful operation and have led to continual revisions of designs during the construction period at other projects, take into consideration the specific characteristics of the structures.

Notizen: Abstract This article supplements and clarifies existing knowledge on processes associated with the early freezing of carbonate stone concrete. Unfortunately, investigations in this field carried out with the participation of the author dealt only with the strength characteristics of the concrete, leaving unclarified, as previously, the effect of early freezing on other properties, particularly resistance to frost and impermeability.

Notizen: Conclusions 1. A redistribution of stresses and strains occurs in the core under the effect of steep rocky flanks which promotes the occurrence of considerable forces of shear resistance in the contact zone. An arch effect is observed in the center of the gorge and the formation of tension zones near the flank abutments of the core. 2. An approximate determination of these changes in stress and strain can be accomplished by the net-point methods on the BÉSM. 3. A comparison of field and calculated data shows a good qualitative similarity of displacements and relative deformations, which indirectly confirms the correctness of the results obtained. 4. Fractures on the crest and a decrease of lateral pressing of the core toward the foundation are the main danger for a core. An estimate of these quantities (including the conditions of development of shear slips) for dams constructed in triangular gorges is possible by means of the equations and graphs presented. 5. For modern earth dams with a core constructed in gorges with steep rocky flanks it is necessary to check the possibility of the formation of cracks, which can be accomplished in the first approximation by the proposed method.

Notizen: Conclusions 1. The limits of settling of fragmental particles fix the width of scattering of a fraction or the distribution zone of its mass. The width of scattering of a fraction is related mostly to the lower limit of sedimentation, which depends on the size of the particles, and the parameters of the acting waves and slopes of the underwater relief. 2. The character of sedimentation is determined by the relation between the lower limit of sedimentation Z and erosion He. When Z〉He the particles are carried beyond the limits of the shoal and after deposition become motionless. This process occurs more intensely the greater the difference between Z and He. With a decrease of this difference the removal of particles decreases markedly and most of them can circulate for a long time within the shoal, slowly adding material to its outer edge. When Z≤He the fragmental material remains entirely on the shoal. During wave action it is mobilized and is capable of continued longshore migrations. The process of alluviation — the delivery of material toward the water's edge—takes place when Z〈 He. The main prerequisites for this are a sufficient size of the fragments and quite gentle slopes of the shoal. 3. The regularities obtained can be used for forecasting the deposition of sediments in the shore zone of large water bodies.

Notizen: Conclusion 1. For rivers on rocky beds the preliminary shield method appears to be the most economical and technically advisable method for building closure sections. From the practical point of view such methods can be used on all rivers. However, the choice of the closure operation should be based on the overall evaluation of the various factors in a given case. 2. When the embankment link up has to be made in the face of increasing river resistance, joining boulders into chains appears to be the most effective measure. Large boulders or concrete blocks may be placed on the embankment to function as “anchors”. 3. Closure of the Angara River showed that under high heads (more than 3–3.5 m) the stream resistance does not subside almost until the last moment and needs special attention and measures till the embankment slopes meet above the water level. 4. No visible erosion of the rocky riverbed could be observed on the downstream side. Loss of materials through erosion was found to be 25% of the total volume deposited during the final stages, which agreed fully with the calculations. A major part of the lost material occurred in the final closure stage when the channel width is less than 25 m. 5. The materials prepared at the construction bases, in particular the boulders, appeared to be adequate for the proposed job. A factor of safety of 1.25 may be regarded as very modest and does not exceed the limits for similar coefficients used on well-known frontal closure projects. 6. The heads and velocities observed in the channel closely agree with the calculations. The dam linking the Pravyi Losenok island with the cofferdam in the final stages created an additional head of 0.3–0.4 m. 7. The total number of automobiles and machines directly participating in the closure operations should be decided upon after providing for adequate reserve strength.

Notizen: Conclusions 1. One of the main tasks was the construction of a core trench having smooth rock surfaces, as well as uniformity and reliability as regards both the filtration characteristics and the bearing ca pacity. These objectives may be achieved under the given conditions by applying first-stage surface blanket grouting through vertical holes and second-stage surface grouting through horizontal holes from the grouting gallery, under the pressure-compensating load from the core. The first-stage surface grouting must be applied to a depth of 6\2-8 m, according to data from experience in foreign countries and the recommendations of the B, E. Vedeneev All-Union Scientific-Research Institute of Hydraulic Engineering (VNIIG). The uneven surfaces must be improved by covering them with concrete. 2. At a certain depth under the core trench and downstream from the grout curtain it may be necessary to construct inspection and drainage galleries for draining the foundation and the slopes, and for observing the filtration conditions under the core. These galleries may be considered as a part of the control-measuring system. An important point is the possibility of seepage along the lateral edges of the dam. This seepage may cause flooding of the hillsides and give rise to landslides, which in fact recently have been observed at the site. In order to provide protection against this phenomenon, it is recommended that deep intercepting drainage galleries be constructed along the edges of the dam. 3. All the \ldkarankulite\rd rock discovered in the zone of action of the ground water should be removed or localized in all cases.

Notizen: Conclusions 1. Yielding of a foundation has a considerable effect on the seismic stability of roundhead buttress dams. The experimental data presented in the article are not complete but can be used in design for taking into account the indicated factor. 2. When a structure is subjected to a seismic load of the traveling-wave type directed along the canyon, the magnitudes of the stresses in the buttress near the base of the dam can prove to be considerably greater than those obtained by calculation or experiment without consideration of this factor. 3. The local stress concentrations arising in the lower part of the dam in the zone of interlocking side planes of the roundhead buttress can be eliminated in the case of a lateral earthquake by means of joints-notches on the side planes of the roundheads or by constructing under each section a yielding interlayer having an increased tensile strength. 4. Sealing of all the intersectional joints of the dam is an effective method of increasing its seismic stability. This method is especially effective under conditions of narrow sites.

Notizen: Conclusions 1. The diversity of the specific construction conditions of impervious membrane elements raises many problems which call for additional investigation. Special attention should be focused on the creation of simpler systems, the improvement of their reliability, and the justification of the durability of the membrane materials. 2. The required simplicity, technical advantages, and reliability of membrane system should be obtained, in particular, through the use of gravel soils in the protective and underlying layers, mechanized placing of these soils, use of other methods than fusion for joining the membranes at the construction site, and imparting convexity into the membrane cover at the places of contact with the banks and the concrete structure as well as over the entire cover area. 3. When the soil is placed by mechanical means, the thickness of the protective layer for a facing on gravelsand or pebbly soil should not be less than 1.0 m and the size of the particles in the underlying layer should be 20–40 mm. 4. A facing made from polymer sheets placed with 0.5–1-moverlaps is equivalent to a clay or loam facing, from the permeability standpoint.

Notizen: Conclusions 1. The usefulness and economy of the temperature observations at the 22nd CPSU Congress Volga hydroelectric plant permit recommending similar methods for the maintenance of hydraulic structures, for other hydraulic developments. 2. For quick adoption of the temperature method of seepage control, it is necessary to select a more rational type of deep electrothermometer and to initiate the manufacture of this instrument at one of the factories of nonstandard devices of the Ministry of Power and Electrification of the USSR. 3. It is necessary to improve the methods of utilization of temperature observations for the control of seepage regime and of the state of structures and their impervious elements (facings, cores, aprons, etc.) on cohesive soils.