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1.
Conclusions  
1.  It is necessary to calculate the strength of branches of penstocks by the finite-element method with the use of programs taking into account sufficiently completely the complex stress—strain state as well as the physical and mechanical properties of the material of the structure.
2.  When designing branches with large parameters it is expedient to use high-strength, sufficiently ductile, readily weldable steels with ultrasonic testing of the continuity of the rolled sheets.
3.  When calculating penstocks and branches concreted in mine workings it is necessary to examine their coaction with the surrounding concrete, and also it is recommended to take into account the unloading effect of the passive pressure of the surrounding rock mass.
4.  The loaded forks should be manufactured according to a special production plan of assembly and welding operations with the use of a technology providing a sufficiently low level of residual welding stresses.
5.  Check assembly and marking of the structural members during manufacture of bulky shaped elements of penstocks and forks as well as quality control of the welded joints during enlargement are necessary conditions of achieving a high quality of operating reliability which rule out losses of time when assembling the members.
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 3, pp. 50–52, March, 1998.  相似文献   

2.
1.  For underground machine halls with a large number of units the areas of the assembly floors should be 1.5–2 times greater than for outdoor hydrosation powerhouses. Zones of the MH adjacent to the vehicular tunnels cannot enter into these areas; these zones should be regarded only as loading areas.
2.  The technology of excavating the underground machine hall, including pits for the draft tubes, introduced at the Hoa-binh hydrostation can be recommended for excavating large chambers of considerable length.
3.  The use of the given technical solutions when constructing underground hydroelectric station and pumped-storage stations in combination with fulfillment of par. 1 of the “CONCLUSIONS” will make it possible to reduce considerably the total construction time of underground machine halls and to provide start-up of all units.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 1, pp. 29–39, January, 1996.  相似文献   

3.
1.  The technological methods of sinking underground structures under the effect of their own weight recommended by the building code and those traditionally used (and also the recommendations on eliminating tilting and sticking) do not provide the normal occurrence of the sinking process and do not preclude the possibility of failures.
2.  Reliable control of the process of sinking drop shafts can be accomplished by using the external active (adjusted in magnitude and place of application) forces, by using a jack-cable system with simultaneous control of the stress-strain state of the drop shaft (stresses in the concrete, reinforcement, pressure under the cutting curb, skin friction of the curb part).
3.  Construction of deep underground structures should be carried out in two and more stages with the use of reliably controlled jack-cable sinking systems.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 1, pp. 51–53, January, 1988.  相似文献   

4.
1.  Forced ventilation accompanying the driving of underground workings leads to substantial temperature fluctuations of the roof surface and to the occurrence of thermal compressive stresses in the roof of the powerhouse. The maximum compressive stresses in the roof are observed at those times of the construction period when the values of the temperature gradients in the radial direction and values of the ratios of the height of the powerhouse to its width are maximum. This circumstance should be taken into account when designing and constructing underground powerhouses of hydrostations under conditions of the Far North.
2.  A tectonic fracture passing near the roof at the initial time of thawing of the mass promotes the occurrence of stress concentration in the roof, increasing the maximum compressive stresses by 3 times in comparison with the case when the rock is solid.
3.  The temperature regime of a perennially frozen rock mass around the powerhouse of a hydrostation during its operation stabilizes within 40–50 years of the constant thermal effect from the machine hall. In this case, a halo of thawed rocks forms. The temperature distribution in the rock mass after 15–20 years of operation of the hydrostation is close to steady.
4.  Thawing of frozen rocks in the operating period of the hydrostation, i.e., the establishment of a steady temperature distribution in the mass, is favorable from the viewpoint of the stress state of the powerhouse. In this case, thawing of the mass leads to a decrease of the values of the thermal stresses in the concrete roof of the powerhouse in comparison with the values of these stresses in the construction period occurring as a consequence of forced ventilation.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 20–26, August, 1988.  相似文献   

5.
1.  Provision for stability of slopes is one of the main problems in designing plains PSHS.
2.  The reasons for occurrence and a chain reaction of development of landslide phenomena on the south slope of the area of basic structures of the Zagorsk PSHS were peculiarities of its engineering-geological structure that were not properly taken into account in designing and carrying out construction work.
3.  For the purpose of stabilizing the landslide slope, a system of engineering measures was developed and implemented, including a change in the configuration and structure of the right-bank abutment of the upper-basin levee to the water intake, construction of a banquette, filling of a counterbanquette, draining of moraine loams, grading of the slope, surface water diversion, and monitoring of the state of the slope and elements of the antilandslide protection.
4.  Data from full-scale observatins indicate the effectiveness of the antilandslide measures that were performed and a state of the slope corresponding to criteria for the hydro development's safe operation.
5.  Innovative elements of the system of measures to stabilize the south landslide slope of the Zagorsk PSHS are:
–  the complex nature of measures, providing for the optimum set of criteria with respect to reliability, technological efficiency, construction time, and cost of adjusted expenditures;
–  minimization of one-time and total excavation for the banquette, providing for the least disruption of the slope in the process of construction;
–  draining of moraine loams, which has no known analog;
–  the use of an ejector unwatering system, which provides for minimum adjusted expenditures on construction and operation of the drainage system.
Deceased.  相似文献   

6.
1.  Oscillations due to low-frequency sources of excitation beneath the impeller in the draft tube develop in long pipelines of water-storage power plants.
2.  For the Zagorsk water-storage power plant with a long (790 m) and flexible pipeline, the natural frequency of the first type of the system's oscillation is many times lower than the predominant frequency of the lowest-frequency component of the spectrum of pressure fluctuations beneath the impeller (0.24–0.25)fre. For a shorter and stiffer pipeline, the system would approach resonance.
3.  The dynamic properties of the system depend on the opening of the guide apparatus: for small openings, the natural frequency approaches f1=(C/4)L; with large openings, it approaches f2=(C/2)L.
4.  When the unit is operating in the stationary mode, the hydrodynamic loads on the pipe lining do not exceed 0.05 MPa; this corresponds to an additional stress of 0.07 MPa in the lining and vibrational displacements of 0.183 mm (when C=780 m/sec), i.e., not more than 0.06 of the radius of the pipeline; when C=965 m/sec, the vibrational displacements do not exceed 0.08 mm.
5.  The loads on the pipeline supports do not exceed 0.36 tons on any one pile.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 27–30, August, 1992.  相似文献   

7.
1.  In certain cases of constructing dams salt-containing soils serve as their foundation.
2.  Under these conditions reliable operation of the structures can be provided only by developing special engineering measures to control dissolution.
3.  All existing methods of protecting saliferous foundation soils of hydraulic structures from dissolution can be divided into passive, active, and combined.
4.  The combined methods should be considered the most effective for preventing removal of salts from foundation soils by the seepage flow.
5.  Large-scale field investigations of the work of the combined method of protecting saliferous foundation soils of the planned Lower Kafirnigan hydro development showed its high effectiveness even in the case of complex engineering-geological conditions at the construction site.
6.  Individual elements of the set of dissolution protective measures investigated under field conditions can be used in hydrotechnical and hydropower construction practice.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 10–14, October, 1994.  相似文献   

8.
Conclusions  
1.  The expediency of hydraulic-fill grading of marshy coastal territories and city dumps for housing construction and recreation park and beach zones was proved practically.
2.  Underwater coastal borrow pits in the shallow-water zone can be used for direct dredging of soil.
3.  In the absence of sand borrow pits, fine-grained loamy sand soils can be used for hydraulic filling the construction sites.
4.  To operate dredges on large water areas under conditions of violent wind-wave action, it is necessary to work out a special works organization plan taking into account the preservation of supply lines, machines, and crew during a storm and under ice conditions in the winter.
5.  The possibility of using the ash of heat and power plants for engineering grading of a marshy territory for housing construction on a pile foundation was proved.
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 9, pp. 29–33, September, 1997.  相似文献   

9.
Conclusions  
1.  Clearing small silted rivers in the Volgograd and Rostov regions by means of floating dredges confirms the expediency of these works for irrigating farmlands, pisciculture, and improving ecology.
2.  Works on clearing and dredging small rivers have their own characteristics, which should be taken into account when working out the technical documents and performing the works.
3.  Simultaneously with channel clearing, comprehensive measures should be taken to prevent erosion of the banks and pollution of the river by wastewaters.
4.  The project documents should be drawn up with consideration of a multipurpose approach to the use of the river’s water resources.
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 6, pp. 41–44, June, 1998.  相似文献   

10.
Conclusions  
1.  In the upper reservoir of the Zagorsk PSS there are standing waves of a complex frequency spectrum having a virtually undamped character.
2.  The excess of the level of the crest of the upper reservoir embankment of the PSS should be selected with consideration of not only waves caused by meteorological factors but also the presence of standing waves.
3.  The standard systems of measuring the upper pool level of the PSS should provide for averaging the measurements.
4.  To eliminate nonproductive water losses through leaks of the close gate apparatus of the PSS units and increased power losses in the SC regime, it is advisable to provide for the installation of preturbine gates at newly planned PSSs.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 39–42, October, 1999.  相似文献   

11.
Conclusions  
1.  At the current stage of hydrotechnical construction designs of structures constructed with the complete or maximum use of natural materials and providing complete mechanization of the construction and repair of structures can be most effective.
2.  It is necessary to begin immediately experimental laboratory studies and to provide standards on the use of natural materials of the sand-gravel mixture type in designs of hydraulic structures.
3.  It is necessary to begin exploration of potential deposits of SGMs and to calculate their reserves.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 17–20, October, 1999.  相似文献   

12.
1.  A comparison of laboratory and on-site data on a determination of the maximum range of oscillations at the end of a direct hydraulic jump when waves enter it from a chute with the results of calculations by theoretical formulas (1), (2), and (3) confirms the applicability of one of these formulas (2) for superrapid flow and flow transitional from superrapid to rapid.
2.  The stilling basin generates secondary waves, reaching half of the depth of the basin d with respect to its height. With submergence of the basin from the lower pool, the range of variations of the level increases additionally by 2.0–2.5 times.
3.  On the apron behind the stilling basin, the drop of waves is insignificant, since the wave transformation coefficient at distance (40–90)hn, where hn is the natural depth, remains equal to .
4.  The periods and lengths of the waves transformed in the stilling basin decrease with increase of discharge and Froude number Fr0 and approach in value the wave periods.
5.  Formulas (6) and (10) were obtained for calculating the maximum amplitude of oscillations of the free surface and maximum depth at the crest of oblique waves on the narrowing sections of the wave chutes and they were checked experimentally, which proved the applicability of these formulas for calculating a nonstationary oblique hydraulic jump.
6.  The proposed empirical formulas (12)–(17) can be recommended for an approximate evaluation of the parameters of the largest first waves on the narrowing stretch.
7.  Under these conditions, the use of a stilling basin as an energy dissipator of a superrapid flow is not rational, since not dissipation but generation of secondary waves is observed in it. When designing narrowing sections of chutes, it is necessary to take into account an increase of depth of the oblique jump with passage of roll waves.  相似文献   

13.
1.  The final stage of damming the Irtysh River was carried out without complications owing to thorough preparation for this important stage of works on the part of the entire team of Irtyshgesstroi.
2.  The cut made to the upper cofferdam and undercutting of the cofferdams by dredges considerably facilitated damming of the Irtysh in the final stage.
3.  When modeling damming, the design and research organizations have to approach this important problem in greater detail and from all sides and to investigate the process with the active help in the investigations of those doing the damming.
4.  Damming of the Irtysh River in the region of Semipalatinsk city was complicated by the considerable difference of the actual drop in the gap and that determined on the model owing to the complexity of modeling such a large river with a multitude of branches.
5.  Damming of rivers in the winter at negative temperatures considerably complicates the works both organizationally and technologically, and therefore preparation for damming should be thoroughly perfected.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp. 13–16, September, 1991.  相似文献   

14.
An analysis of the experience in the Soviet Union and in foreign countries with conveyor transportation in the mining industry, as well as with use of conveyors in hydraulic construction shows that the introduction of conveyor transportation in the field of construction of embankment dams in this country, for delivery of earth-rock material from quarries, as well as for carrying raw materials to concentrating plants processing nonmetallic minerals, will make it possible.
1)  To reduce substantially the personnel nees.
2)  To lower significantly the transportation costs for delivery of earth-rock materials to construction sites and to concentrating plants processing nonmetallic mateirals (rubble, gravel, and sand);
3)  To reduce the need for trucks, by replacing them with conveyors;
4)  To increase the rate of delivery of earth-rock materials from quarries for dam, construction and, consequently, to reduce the times of completion.
5)  To reduce the volume of housing, cultural-welfare, and auxiliary-subsidiary construction in owing to the lower needs for personnel in conveyor transportation;
6)  To eliminate the need for constructing a large number of roads with rigid pavements for large-capacity dump trucks;
7)  To raise the technical level of the earth-rock work.
  相似文献   

15.
1.  Grout curtains are a structural element of the underground contour of dams with a limited service life. A gradual decrease of the modulus of deformation of the foundation and deterioration of its other characteristics occur as a result of leaching of the cement.
2.  Estimation of the life of grout curtains and determination of the overhaul period should be carried out differentially on the basis of particular values of the rate of the leaching process. For example, the average rate of removal of calcium oxide from the grout curtain in the foundation of one section of the Sayan-Shushenskoie dam is 7.5 and of the Zeya dam, 9.4 mg/sec.
3.  It is necessary to broaden the study of the behavior of grout curtains at operating concrete dams to establish performance criteria at various stages of life of the structure.
4.  The volume of grouting works on a grout curtain should be assigned on the basis of the required life of grout curtains, assuming that the life is proportional to the square of their thickness.
5.  When designing the underground contour of dams, the parameters of the drainage system should be assigned with consideration of the destruction of the grout curtains occurring and prevention of overloading of the drainage systems. At the dam designing stage it is necessary to provide the possibility of conducting effective restoration of the serviceability of grout curtains.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 7, pp. 21–24, July, 1992.  相似文献   

16.
1.  Modified wood is an effective substitute of the laminated wood lining of bearing bushings for vertical pump units.
2.  An investigation of modified wood showed that this material in some indices (friction coefficient and wear resistance) is better than laminated wood.
3.  Since there is no mass manufacture and centralized supply of modified wood, it is possible to create a technological department for its production.
4.  Organization of the department does not require capital expenditures and special accommodations.
5.  Machining of the wood is performed on ordinary metal-cutting machines with the use of the tools used when machining laminated woods.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 7, pp. 33–35, July, 1991.  相似文献   

17.
1.  Practically all measures related to the creation of reservoirs take into account problems of the rational use of natural resources; the implementation of these measures will reduce or minimize the adverse effect of reservoirs on the environment.
2.  It remains to perform extensive research, including long-term observations on existing reservoirs, in order to gain greater knowledge about the interaction of reservoirs with the environment, which will permit developing measures whose accomplishment will reduce still more their adverse effect on the environment and in some cases will lead to an increase in the natural resources of our country.
  相似文献   

18.
1.  The energy-storage hydroelectric station (ESHES) can provide a 1.5–2-fold increase in peak capacity with a simultaneous threefold decrease in daily fluctuations of the water level in the lower pool.
2.  A decrease in the length of the concrete structures located in the river channel (especially the length) of the powerhouse) reduces the consumption of concrete for the ESHES in comparison with the HES, which compensates for the cost of constructing the additional structures of the ESHES.
3.  Unlike the HES, the ESHES operates in a sharp-peak regime and also during passage of flood waters.
4.  Contrarotating pump-turbines are best suited for an ESHES because of various combinations of heads on its turbine and pump parts.
5.  With increase in the speed of multistage hydraulic machines their placement depth decreases and the cost of the powerhouse is reduced.
  相似文献   

19.
Conclusions  
1.  Gidrospetsproekt should design the groundwater system.
2.  One contractor should drill the wells and operate the groundwater-lowering system.
3.  In connection with the geological conditions, the wells should be of very high quality, for which own enrichment of the filter material (sand of the blanket) and strict control during drilling the wells are necessary.
4.  It is efficient to drill the wells by a 1BA-15V rig with a tool with backwashing.
5.  With respect to piles of the penstock foundation: Drilling the holes for the piles should be done only with casings. To organize 24-h work for increasing productivity. Works on forming the pile heads should be done immediately after concreting the pile. The piles should be tested after each change in the geological conditions.
6.  With respect vertical drainage: the wells should be of high quality, with an enormous safety margin.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 29–33, October, 1999.  相似文献   

20.
Conclusions  
1.  When designing pipelines on collapsing soils it is necessary to take into account the most unfavorable conditions from the viewpoint of bending of the pipeline—settlement of the intermediate supports every other one, all even or all odd.
2.  In this case, if the amount of deflection of the penstock under load is less than the amount of settlement of the intermediate supports, it is necessary to take into account disconnection of the intermediate roller support from work.
3.  Control assembly of members of the assembly links during manufacture of the oversize penstocks as well as quality control of the welded joints during enlargement are necessary conditions for achieving a high quality and eliminating losses of time during assembly.
4.  To shorten the time of construction and assembly works, provided a thoroughly conducted geodetic survey, it is expedient to assemble the penstock from two sides—from the side of the water intake and from the side of the powerhouse.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 1, pp. 40–45, January, 1997.  相似文献   

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