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1.
1.  In addition to the technology of manufacturing and installing precast concrete-encased steel penstocks of PSSs that has been developed and realized, the technology of manufacturing in situ penstocks can be developed. It is necessary at once to carry out design studies and to conduct additional scientific investigations for the purpose of comparing the two variants of technologies and to select the optimal one.
2.  The construction of in situ concrete-encased steel penstocks of PSSs can provide a noticeable intensification of construction and a reduction of labor intensity and cost of the structure. According to the data of the authors themselves of the design of the precast concrete-encased steel penstocks of PSSs, the cost indices of the in situ penstocks are substantially smaller.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 1, pp. 11–14, January, 1989.  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.
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   

4.
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   

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.  When ventilating complex underground hydraulic systems during their construction it is necessary to take into account the natural draft.
2.  The method presented for calculating the natural draft pressure drop of single tunnels (formulas 1–6) reflects the specific characteristics of hydrotechnical construction in mountainous areas and for the first time takes into account the direction of movement of the ventilation flow.
3.  For the particular conditions of constructing the Rogun hydrostation the values of the lapse rates were established, which can be used in calculations to take into account the natural draft when designing the ventilation of underground workings.
4.  For calculating the natural draft pressure drop of a complex network of underground workings, an algorithm was developed which makes it possible to calculate by a standard program on a computer the air distribution in the underground complex being constructed in relation to a number of technological and natural factors.
5.  On the basis of analyzing the results of different variants of the air distribution, the selection of the types and arrangement of the ejector fans (including in the future) was optimized, making it possible to increase the quality of ventilation and safety of underground operations, as well as to obtain a substantial technical-economic effect.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 26–29, August, 1988.  相似文献   

7.
1.  Small hydrostations under high-mountain conditions should operate with trash racks, devices should be provided for their cleaning from trash and shuga, as well as shuga-deflectors into the diversion canal.
2.  To reduce abrasion of the turbine equipment, it is necessary to provide operation of the suspended-particle settling basins.
3.  Specifications on the assembly of bearings and movable couplings should be developed for conducting maintenance works.
4.  During restoration works the profile of the runner blades should be made strictly according to the template in conformity with the plant drawings.
5.  Extremely necessary is the equipping of hydrostation with means for monitoring the technial parameters (bearing temperature, water pressure in the passage, wobble of the shafting, etc.), observation of the changes in which will make it possible to carry out in good time preventive maintenance and to reduce the probability of occurrence of breakdown.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 3, pp. 43–45, March, 1990.  相似文献   

8.
1.  For the first time in Russia a submersible axial-flow dredge pump was developed and tested for installation as a first-stage pump on dredges to reduce the negative pressure before the hold dredge pump and to increase its positive suction head.
2.  The use of the axial-flow dredge pump permits increasing the output of the dredge and depth of excavating the underwater borrow pit. With respect to power consumption the axial-flow pipe is 2–3 times more economical than ejection.
3.  The small mass of the pump permits mounting it on existing dredges without their alteration.
4.  Development and perfection of this direction is quite prospective for hydraulicking.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 14–17, October, 1995.  相似文献   

9.
1.  Hydraulic investigations of T-shaped forks made it possible to refine the character of head losses in the junction of the tank with the conduits. The use of the dependences obtained in calculating the stability of the regimes of a hydroelectric station just due to a more accurate consideration of the effect of the velocity head in the base of the surge tank permits substantiating a considerable decrease of the critical area of downstream surge tanks.
2.  In calculations of the critical area of downstream surge tanks it is necessary to include in total head losses the velocity head in the outlet section of the outflow channel. In this case the value of the critical area decreases.
3.  The proposed method of analyzing the stability of HES regimes with the use of the Routh algebraic criterion permits relating the adjustment parameters of the ARS, turbine characteristics, and power system among themselves to the area of the surge tank and solving the problem of stability in the complex.
4.  At hydrostations with short outflow pressure conduits it is advisable to take small, up to 10% of the Thoma critical, cross-sectional areas of the surge pipe of a surge tank with an expansion chamber. This makes it possible, on one hand, to reduce the amount of works on the tank and, on the other, to provide stable regimes of the hydrostations while retaining the adjustment parameters of the ARS.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 4, pp. 40–43, April, 1995.  相似文献   

10.
Conclusions  
1.  A set of measuring devices needed for operating a dredge was developed on the basis of domestic Sapfir-22 pressure transducers with protection of the pulse tubes by blowing or shutting in the air and was tested.
2.  A high reliability of the measuring set was found, it is recommended for wide use on dredges.
3.  The scheme of connecting the electrode detectors of the conductometric consistometer was improved, their series connection increases the accuracy of measurements by equalizing the electrode polarization process.
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 7, pp. 28–30, July, 1999.  相似文献   

11.
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   

12.
1.  A method was developed for calculating structures for static and dynamic actions with consideration of deterministic and probabilistic approaches to the solution of the problems.
2.  The strength and reliability of structures of the machine hall of the powerhouse during discharge of floodwaters were estimated with the use of methods of statistical dynamics.
3.  Elements of reliability theory of engineering systems were used in estimating the reliability of the structures.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 4, pp. 25–31, April, 1994.  相似文献   

13.
1.  A pressure dangerous with respect to cavitation is observed in those places where the vortex core closely approaches the conduit wall (there are places where with formal conversion to the prototype vacuums m H2O are observed, actually the absolute values will be close to the vaporization pressure).
2.  Delivery of air to ducts for the given spillway design reduces but does not remove the dangerous vacuum on the conduit walls.
3.  Large vacuums are recorded both over the length of the outlet conduit and in the dissipation chamber.
4.  The most effective (of those investigated) means of eliminating the vacuum on the conduit wall and in the dissipation structure are the installation of longitudinal ribs and transverse diaphragms in the outlet tunnel and delivery of air to the end of the swirler and dissipation chamber.
Deceased.  相似文献   

14.
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   

15.
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   

16.
1.  The data base for existing ACS PP at hydroelectric plants can be successfully employed as points for monitoring the conservation of an environment of local significance.
2.  It is expedient to discuss this problem with organizations, including local control groups interested in the development of territorial-basin systems for ecological monitoring.
3.  The initiative in creating local territorial-basin support points for monitoring should emanate from guidelines for hydroelectric plants with ACS PP.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 12, pp. 1–4, December, 1992.  相似文献   

17.
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   

18.
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   

19.
1.  The hydraulic characteristics of cohesive mudflows in the case of a hydraulic jump, other conditions being equal, differ considerably from those for a pure water flow.
2.  The scheme of calculating a hydraulic jump of a cohesive mudflow requires taking into account, along with the hydrostatic pressure, also the pressure caused by cohesive forces and angle of internal friction of the mudflow mixture.
3.  The change in the ratio of the depth H2/H1 before and after the jump completely depends on the kinetics parameter of the mudflow, values of cohesion and angle of internal friction.
4.  Several subcritical depths, determined by the concentration of the mudflow mixture and physical and mechanical properties of the medium, correspond to the jump function of a cohesive mudflow.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 12, pp. 45–47, December, 1991.  相似文献   

20.
1.  Effective designs of floated-in blocks of a TPS with a one- and two-tier arrangement of the turbines were developed on the basis of a unit with an orthogonal turbine.
2.  Layouts were obtained with the use of blocks of the proposed design for a TPS making possible a radical reduction of capital expenditures and construction time.
3.  It is expedient to develop the layouts and designs at the detailed design level, as well as with respect to the construction of river low-head hydroelectric stations.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 2, pp. 11–13, February, 1992.  相似文献   

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