As a result of this, during operation of the unit the bushings of the oil header are extremely heated and bind the rods and frettings occur on the rods and through cracks on the bushings.In the majority of cases misalignment of the shaft and oil header occurs as a consequence of a considerable increase of the gap between the shaft and bearing of the generator, which, as a rule, leads to binding of the upper end of the rods.In the case of considerable heating of the oil header and oil, stopping of the unit should be preceded by conversion of the blades to manual control. In the case of emergency stopping, owing to the automatically occurring turning of the blades to a starting angle (downward movement of the piston rod of the servomotor of the runner) the flange connection of the rods with the piston rod can be broken off as a consequence of their binding in the bronze bushings of the oil header.Careful attention to the oil header in the stage of its development, manufacture, assembly, and operation invariably ensures reliability and trouble-free operation. For this purpose, the design thickness of the rod walls, correct centering of the unit, and thorough cleaning of the oil of the control system are necessary. The main cause of sliting of mountain reservoirs is the sediment load of the rivers. Silting can also be causedby landslides and falls, mudflows, products of reworking of the reservoir banks by waves, and wind-borne sediments. If the reservoir is large, the process of silting is divided into two periods. In the first period all sediments remain in the reservoir and the volume of silting is equal to Ws= (Wt~m+V)T, ~us =Ha/Pdep, (i) The end of the first period is determined by the relation [i]W--O,2Vm, r (2) Tult = W1.su s + V"In the second period, when the sediments begin tobe partially discharged into the lower pool, the volume of silting is determined by the following formula [2]:W,. sus~ wult J where Vm. r is the mean annual runoff of water to the reservoir; T, silting time, years; Wul t, ultimate volume of silting, equal to the volume of the reservoir minus the volume of the channel which remains in the reservoir after its complete silting; Wl,su s, volume of the suspended load which remains in the reservoir in the first year of its silting or, if there is a first period of silting, in the first year of the second period where ~a is the mean annual mass of the suspended load (dry), determined from the State Water Inventory (when a reservoir already silted is present on the river a correction is desirable, since the runoff of the suspended load is underestimated); ~r and ~ri, crosssectional area of the dam stretch of the reservoir and river under natural conditions during passage of the dominant discharge; n an exponent which varies for mountain rivers fromTranslated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp.
It is necessary, however, to take into consideration the fact that the fate of any water management scheme, project, or facility depends primarily on the validity of the hydrological/water management portion of the plans, inadequate proof of which is often decisive in a negative assessment when the plan is reviewed. Construction of any specific water project outside a solidly grounded plan for multipurpose water resource utilization always entails losses to the economy, together with lowering of its water-management and economic benefits.The editors invite the readers of this journal to take part in discussing ways to increase the reliability and level of evidentiary support for water projects proposed for implementation.
Inclusion of the technical session D "Deposition in Estuaries and River Mouths" in the program of the 14thCongress of the IAHR was due to a number of circumstances closely related to the economic utilization of the regions of river mouths and seashores. In connection with the trend toward an increase in the size of shil~ , especially tankers, the ixoblem of cow'trolling deposition in the approach channels is becoming exceptionally urgent. Mud-botZom channels subjected to tidal currents are of particular interest.In recent years problems of the hydrodynamics of fiver mouths and shores have also acquired importance in connection with the creation of large reservoirs for power purposes on rivers emptying into the sea, since the retention of sediments in reservoirs causes intense wave erosion of the shore. To forecast the consequences of streamflow control by re.~rvoirs with respect to the stability of the seashore, it is necessary to have a clear idea of the disrribution of sediments within the estuatine shore, which requires the development of the hydrodynamics of river mouths and shores.Finally, the prediction of changes in the hydrologic regime of rivers in connection with diversion of the runoff from the basin to another for the purpo~ of maintaining a sanitary condition of the river mouths, supplying drinking and industrial water and for reclamation, fisheries, etc., also requires a more comprehensive study of the hydrodynamic regime of river mouths and estuaries.At technical session ]3, 28 reports were presented: six from the USA, four each from the USSIL France, and Great Britain; two from Holland; and one each from India, Turkey, Portugal. Japan. Brazil. Mexico, Canada. and West Germany. These reports can be divided into the following groups according to the character of the investigations: a) theoretical methods of predicting the deposition of sediments in estuaries and transformation of the shore in the region of river mouths (reports 1, 5, 10-14, and 19); full-scale investigations of deposition in river mouths (reports 4, 13, 16, 21, and 28-28); c) experimental study of sediment transpcet in rivers and estuaries on physical and mathematical models (reports 2, 3, 6-9, 11, 12, 17, 18, 20-24, and 26). The brief content of these reports, of interest to Soviet hydraulic engineers, is given below.A. Harrison and M. Owen (D.I,~" England) investigated the transport of fine sediment in estuaries as a recurring cycle of four processes: erosion, transport of suspended sediment, its deposition and consolidation. Each of these processes depends on the hydraulic regime of the flow and characteristics of the sediment and can be expressed only by empirical formulas Qith constants obtained in the laboratory and in full-scale observations. The report discussed the prediction of deposition in the ship channel on the Pleit River located perpendicular to the stream.S. C-oul, Z. Tarapor, and S. Brahme (D.S, India) presented a method of predicting deposition in harbors and channels based on an analysis of full-scale, model, and...
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