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1.
1.  The designs as well as the total safety factor of concrete-encased steel pressure conduits of operating hydraulic structures were analyzed.
2.  The principles of the existing standards related to calculations of concrete-encased steel pressure conduits were analyzed.
3.  Methods of calculating concrete-encased steel pressure conduits (including forks and distributors), including elements of the inside steel shell and reinforced-concrete part, were developed.
4.  The calculation methods developed were experimental substantiated and tested during designing and constructing domestic and foreign objects.
Translated from Gidrotekhnicheskoe Stroitel'stvo No. 1, pp. 37–44, January, 1999  相似文献   

2.
1.  Tests confirmed the reliability of the work of the reinforced concrete-encased steel design of the link of the penstocks of the Zagorsk pumped-storage station in the range of pressures up toP=1.4 MPa. The lining of the link and hoop reinforcement of the inside and outside rows take the tensile load in the elastic stage.
2.  The allowable opening of cracks for reinforced concrete-encased designs of a penstock with an inside sealing lining in the range of pressures up to 1.6 MPa with a width of the cracka c 0.2 mm does not exceed the standard requirements.
3.  The test of a particular link showed that with loading by an internal pressure the lining takes 30%, the reinforcement of the inside row 23%, and the reinforcement of the outside row 47% of the external load.
4.  The tests confirmed the complete correspondence of the work of the link to the design data and earlier investigations carried out in a range of pressures exceeding the operating pressure by 30%.
Deceased.  相似文献   

3.
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   

4.
1.  A concrete-encased steel pipeline should be calculated for a uniform internal pressure in the ring direction according to the scheme of a multilayer pipeline with consideration of the formation of cracks in the concrete.
2.  In the limit state, limited plastic deformations of the pipeline materials, leading to some redistribution of forces in the rings and to the rational use of metal, are admissible. Here opening of cracks in concrete should not be greater than is allowed by the standards.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 4, pp. 5–11, April, 1993.  相似文献   

5.
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   

6.
1.  The prefabricated cutoff wall as one of the economically justified designs can be regarded as the main watertight element of an earth dam.
2.  The cutoff wall can be made from precast asphaltic concrete and concrete blocks and combined — from both joined together on asphalt mastic. An analysis of the stress-strain state showed that each of these walls has a sufficient margin of deformability.
3.  The cutoff wall of precast concrete blocks, eliminating the use of asphalt for its construction and having a practically unlimited margin of deformability, can be of interest to designers and builders.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 11, pp. 11–14, November, 1993.  相似文献   

7.
Conclusions  
1.  The experience of designing, constructing, and operating the Zagorsk PSS confirmed the correctness of the decisions made earlier about constructing a series of large PSSs in the country, their technical need and economic expediency.
2.  When examining the question of constructing new PSSs, it is advisable to take the same main equipment as at the Zagorsk PSS as the basis. This will make it possible at all stages of creating a new PSS to considerably reduce material and financial expenditures and to shorten construction time.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 9–12, October, 1999.  相似文献   

8.
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   

9.
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   

10.
1.  Rollcretes can meet the requirements of construction concrete with a high strength, impermeability, and frost rsistance and, in particular, can be used with great effectiveness for constructing hydraulic structures such as arch dams, retaining walls, abutments, etc. Furthermore, road pavements, landing strips, and taxiways can be constructed from them.
2.  With consideration of the relative cheapness of low-cement rollcrete, in a number of cases it is possible to replace reinforced-concrete members by pure concrete ones, keeping in mind the high cost of reinforcing steel.
3.  The technological characteristics of rollcrete enable doing away with framework at the concrete-ground contact, which is important when constructing transition structures.
4.  It remains to develop a technology of equally strong joining of layers of high-strength rollcrete, which will require a rather large volume of experimental works.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 7, pp. 8–10, July, 1992.  相似文献   

11.
1.  The relative method of measuring the flow rates of water through a turbine is realized by simple means and provides a sufficient accuracy for the needs of hydrostation operation.
2.  Further works of design organizations, operating services, and manufacturing plants is necessary for increasing the reliability of the entire flow-rate measuring system.
3.  The operating staffs of hydrostations need to be materially encouraged to use the discharge efficiently for producing electricity.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp. 28–31, September, 1989.  相似文献   

12.
1.  One of the new approaches to the use of wave power plants can be their use as a source of compressed air for operating a pneumatic breakwater.
2.  The use of wave power plants for protecting marine hydraulic structures from the effect of storm loads makes it possible to increase the cost effectiveness both of the WPPs themselves and of the hydraulic structures.
3.  A rough estimate of the cost of wave power plants shows their effectiveness as a source of electrical energy for remote regions of the USSR.
4.  The simplicity of the design of wave power plants enables organizing their mass production at shipyards or at the site of construction.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 2, pp. 7–10, February, 1992.  相似文献   

13.
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   

14.
Conclusions  
1.  When searching for the optimal steel percent needed for providing the bearing capacity of a specimen, it is necessary to take into account the factor of reinforcement arrangement in the soil.
2.  It is seen from the dependences γcd*=f(ζ) obtained for specimens with various steel percent that with an increase of the factor of reinforcement arrangement in soil ζ the work conditions factor decreases, which makes it possible to introduce the given factor in formula (1) for determining γcd*.
3.  The lining of the model must be regarded as an element increasing the bearing capacity of the reinforced earth model.
4.  In the case of a discontinuous and continuous lining the bearing capacity of the models (with the same steel percent) is higher than that of models with a flexible lining.
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 3, pp. 19–21, March, 1998  相似文献   

15.
1.  Conversion of the gravity dam from traditional to reduced shapes can be effected with a more complete utilization of the compressive strength of the concrete and by permitting cracks to open in its upstream face.
2.  The following structural measures should be taken to guarantee the stability and strength of the type of dam proposed: a) the installation of a lining along the upstream face and a system of drains developed behind it; b) carrying the grout curtain upstream and joining it with the dam.
3.  The set of computations performed and the model studies conducted confirmed the strength and stability of the dam design that we developed.
4.  The proposed design makes it possible to reduce the volume of concrete and the cost.
  相似文献   

16.
Conclusions  
1.  The design of the steel-reinforced concrete pressure conduit was checked for four calculated cross sections: I-I, II-II, III-III, and IV-IV. The calculated check was made in accordance with Russian standards by analytical and numerical methods. The usual load combination of the operating period was taken as the main variant.
2.  The calculations showed that the strength condition of the conduit is fulfilled; in this case there is a considerable safety factor with respect to the shell and reinforcement, which attests to the degree of reliability and safety.
3.  Calculations of stresses in the steel shell and reinforcement by the FEM were made on the bases of finite-element models of cross sections with consideration of the formation of cracks in them. The calculated stresses do not exceed the strength of the steel shell and reinforcement.
4.  Conduit cross sections under temperature effects were calculated. Annual variations of the temperatures of the air, water, concrete of the dam, etc., were taken as the loads. The calculations showed that thermal stresses in the steel shell and reinforcement increase by not more than 24 MPa.
5.  A check of the design of the steel-reinforced concrete conduit showed complete fulfillment of the strength condition and high reliability of the design. The design of the steel-reinforced concrete conduits is recommended for realization when constructing structure of the Three Gorges hydro development.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 4, pp, 40–45, April, 1999.  相似文献   

17.
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   

18.
Conclusions  
1.  Russian hydropower engineering is a competitive branch of power engineering on the world market.
2.  The Russian Ministry of Fuel and Energy must create conditions for the formation and participation of domestic consortia in bids for turn-key delivery of equipment to Russian hydrostations, which will make it possible to reduce the cost, shorten construction time, improve quality, and ensure putting the units into operation on time, i.e., to use objective market mechanisms.
3.  On the initiative of the customer, certain conditions of storing, making up complete orders, delivery, and technology of installing equipment traditionally established between the customer and equipment suppliers should be revised by means of consortia for purposes of reducing costs and improving quality.
4.  One of the most important conditions for the successful work of the consortium is the clear-cut differentiation of responsibility between participants of the consortium.
5.  The date of synchronizing the unit should be taken as the date of reckoning the warranty period of the equipment.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 7–9, October, 1997.  相似文献   

19.
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   

20.
1.  The hydraulic projects awarded prizes by the Council of Ministers of the USSR in 1976 solve a set of critical national-economic problems and are distinguished by high cost effectiveness.
2.  Structures distinguished by originality and progressiveness of technical solutions, which ensure their reliable operation, have been constructed as the result of a set of scientific-research and design studies. This was made possible only by the close creative understanding and interaction between the scientific-research, planning, construction, and operating organizations.
3.  In building hydraulic structures, all the more attention is focused on industrial aesthetics. The architectural-planning solutions of the prizewinning projects are new, represent examples of the progressive development of industrial architecture, and have obtained widespread public recognition.
4.  The bold and economic solutions relative to the organization of the passage of flood waters over incomplete structures merit attention; this makes it possible to reduce the volumes of the enclosing foundation pits of the cofferdams, or eliminate them entirely.
5.  The experience gained with the design and construction of the prizewinning projects should be studied in detail and publicized for purposes of utilization in subsequent design and construction.
  相似文献   

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