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1.
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   

2.
1.  To reduce the cost and construction time of hydro developments, it is necessary to introduce more widely continuous concreting technologies. Concreting of heavily reinforced and thin-walled structures and members is most effectively done with cast concrete mixes by means of modern concrete pumps.
2.  As a result of experimental investigations of pipeline delivery of mixes by BN-80-20 concrete pumps, the values of the specific resistances during pumping of various compositions of the mixes and the local resistances of quick-disconnecting pipe connections were determined; recommendations were developed for calculating the distance of pipeline transport of the mixes by the concrete pumps; the values of Kf, the volume filling of the transport cylinders of the concrete pump with the plasticized concrete mix, and Kd, the inertial component of the pressure during displacement of the mix, were refined.
3.  The two-year experience of using the means (conveyors, concrete pumps) of craneless technology of placing concrete for construction of the powerhouse of the Shul'binsk hydro development showed that even with the high price and underutilization of the potential possibilities of the equipment and mechanisms, a considerable savings was obtained due to shortening of the construction time and start-up of the first unit of the hydrostation ahead of schedule.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 38–43, October, 1990.  相似文献   

3.
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   

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.  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   

6.
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   

7.
Conclusions  
1.  The systems of elongated triangles located at elevations 413, 467, and 344 m do not give reliable results, as a consequence of which they cannot be used as horizontal displacement meters.
2.  The displacements of the ends of the adits recorded from the NET readings are a consequence of measurement errors.
3.  The use of string systems as horizontal displacement meters of hydraulic structures can be used only with their complete protection from airflows, which is practically impossible to do.
4.  The use of 3-m invar bars, used as meters of the small sides of the NET, for determining deformations of concrete and bank adits is possible.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp. 52–54, September, 1998.  相似文献   

8.
1.  Absorbing formwork has a substantial effect on concrete quality for concretes with W/C0.365.
2.  The concrete surface quality depends on the quality of the absorbing formwork materials used.
3.  The possible amount of water removed from the concrete by means of the absorbing (vacuum) formwork was 2.4–3.57 kg/m2.
4.  Before the start of hardening of the concrete, its water content decreases by 20–30% at a depth to 15 cm from the absorbing formwork. During hardening of concrete, its water content equalizes over the entire length of the specimen (thickness of the block), and under these conditions the W/C ratio of the concrete near the formwork is not more than 1% below the initial.
5.  According to the results of testing the concrete for cavitation resistance, the best indices were noted for formwork containing ensonite. In this case, the cavitation resistance of the concrete was increased up to 1.4 times. The latter circumstance permits recommending for use as formwork absorbing material fine-porous paperboard of the ensonite type (with pore sizes 20–100 Å), which freely passes water molecules but retains cement particles.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 11, pp. 39–41, November, 1989.  相似文献   

9.
1.  The use of the results of on-site investigations of an irregular wave load on slopes of structures makes it possible to increase the reliability of designing structures.
2.  A differentiated consideration of the wave load according to probability in storms represented by corresponding quasi-steady wave systems can substantially reduce the cost of construction and installation works on objects of various classes and technical purposes.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 12, pp. 24–27, December, 1989.  相似文献   

10.
Conclusions  
1.  The characteristics of reconstructing hydrostations impose individual requirements on the solution of problems of carrying out construction and installation works in the powerhouse. Therefore when developing new technologies and designs main attention is devoted to reducing labor intensity and cost of installation works, shortening installation time, and increasing reliability in the quality of the structural members being installed.
2.  On the basis of a functional and cost analysis, the conditions were determined and the method of comparing variants of technological solutions of installing power equipment of hydrostations; the optimal variant precluding the possibility of occurrence of excessive expenses both during reconstruction and operation of the object was selected.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 11, pp. 18–21, November, 1998  相似文献   

11.
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   

12.
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   

13.
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   

14.
Conclusions  
1.  In connection with the fact that potentially unstable masses exist in the immediate vicinity of the dam and powerhouse, which are referred to as Class I structures in terms of capital expenditures, the approach taken for the design of PUM stabilization should be nonstandard with consideration given to a number of permanent vibratory design loads introiduced by operating hydraulic units and spillways, as well cyclically varying loads due to the weight of the water in the reservoir and the weight of the structures.
2.  It is proposed to define the volumes required for PUM stabilization of the left-bank slope more precisely on the basis of observations of PUM during construction and operation of the hydroelectric plant. The interruptions that have occurred in the instrument observations should therefore be recognized as impermissible.
3.  Construction and operating experience has demonstrated that it is expedient to perform work on stabilization of potentially unstable masses prior to the start of construction on entities located in their immediate vicinity.
4.  A protective rock wall built at the foot of the slope cannot provide for the complete safety of the structures located close to the left-bank slope during the collapse of rock blocks or individual stones.
5.  On-going monitoring of the condition of the left-bank slope does not correspond completely to problems of providing for the safety of the structures and personnel at the hydroelectric plant by reason of the low reliability of the measuring equipment.
6.  Use of the automated “Relos-L” system for observations of the condition of the rock masses will make it possible to carry out continuous on-going monitoring within the framework of the automated production-control system at the Sayano-Shushenskoe hydroelectric plant. Only a multifunctional monitoring system, which includes different kinds of independent observations, can provide a sufficiently valid evaluation of the state of the PUM, and, on their basis, determine measures to prevent possible emergency situations.
7.  The collapse of PUM in the initial stage of construction with subsequent plaining of the slope and the organization of multistory rock-entrapping benches is a more reliable, safe, and, probably, economical (if expenditures for future operation are assumed in the calculation) method than their stabilization.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp. 67–71, September, 1998.  相似文献   

15.
1.  Processes of variation of the dam-foundation-abutments system are not fading away, the operating regime of the structure has not stabilized.
2.  The unsteady and inelastic work of the bank abutments, evidently, is one of the causes of irreversible radial movements and development of fracturing in the first column of the dam.
3.  Cracking on the upstream face and progressive seepage through the concrete of the first column worsen the state of the concrete and the cracks are subject to healing by polymer materials. Polymer injections do not improve the work of the structure, but if the cracks are not healed promptly the volume of necessary repair works will increase with the course of time.
4.  To evaluate the stress state of the dam it is necessary to make calculations with consideration of the large stress raisers: water intakes, gate grooves, etc.
5.  It is required to evaluate the fact of the excess by a factor of 2–3 of the increments of the maximum arch stress over the design values in various load ranges.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 4, pp. 21–25, April, 1994.  相似文献   

16.
1.  The reconstruction and repair of hydraulic developments is connected with the need for demolishing a significant volume of plain and reinforced concrete structures.
2.  In the Russian and world practice, there is now a wide set of modern methods of demolishing plain and reinforced concrete structures and means of mechanization of heavy manual operations. A substantial number of items of equipment and devices for this work is produced by the Russian industry or can be manufactured on the basis of special orders.
3.  For the carrying out of this work within short periods with low labor costs using modern techniques and effective equipment, it is necessary to create mobile specialized subdivisions. Such subdivisions could be developed either on the basis of existing organizations, for example the Gidrospetsstroi, the Énergomekhanizatsiya, the Gidromontazh, the Spetsgidroénergomontazh, etc., or on the basis of organizations engaged in operation of hydraulic developments.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 42–45, August, 1991.  相似文献   

17.
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   

18.
Conclusions  The Zagorsk PSS—the first pumped storage stations with a capacity of 1200 MW—was constructed slowly, for a long time. The main reasons for this were:
1.  Location of the site in an industrially developed district, near Moscow, with the assumption of the rapid formation and use of available construction facilities did not prove to be correct. Administrative restrictions in welcoming skilled personnel to the construction project did not foster a build-up of the team. A residential village and construction facilities were fully needed, as on any construction project.
3.  Counting on the use of local borrow pits in the Moscow region was not justified: the inert materials were not suitable for hydrotechnical concrete of high frost resistance and strength.
3.  Inadequate engineering-geologic surveys during planning led to late landslide-control measures and to an increase of the volume of CAWs.
4.  When determining the construction time the climatic conditions in the zone of the construction site were underestimated: the number of days without precipitation is 175, not more. The main cause of the wrong design construction time was the incorrect determination of the estimated cost of the CAWs.
5.  Construction of a large hydro development, as the Zagorsk PSS, by the work-effort method with the enlistment of a large number of organizations from different regions of the country did not promote the formation of a stable team at the construction site.
6.  The management of Mosénergo made the right decision: from the examined 10 variants of the next pumped-storage station in the Central region was selected the variant of constructing the Zagorsk PSS-2 where a team of builders took shape after long years, where there are a residential village and construction facilities, and solid experience has been acquired. This will make it possible to shorten the construction time and to reduce the cost of an installed 1 kW of the PSS.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 13–16, October, 1999.  相似文献   

19.
1.  The arch dam of the Khudoni hydrostation can be constructed by the continuous conveyor technology as enlarged blocks.
2.  The rate of concreting the dam for the proposed dimensions of the blocks and times of covering them can reach 200–250 m3/h.
3.  To attain the indicated rate of concreting, it is necessary to construct near the dam site a new concrete plant with facilities for cooling or heating the concrete mix.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 13–14, August, 1990.  相似文献   

20.
Conclusions  
1.  The developed method of strengthening lock chamber walls based on the use of prestressed beam members was substantiated by comprehensive calculations.
2.  The proposed method was realized successfully during strengthening and repair of the chamber walls of lock No. 1 of the Moscow Canal (sections No. 1–15).
3.  On-site observations of the behavior of the structures after their strengthening showed a substantial decrease of seasonal displacements of the lock walls and cessation of slipping of fragments of the walls into the chamber.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 4, pp. 17–21, April, 1999.  相似文献   

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