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1.
1.  As a result of the investigations, the distribution of the discharge and current velocities in braided channels of a flatland river under natural conditions and with the implementation of various engineering measures was obtained. The effective measures on regulating the distribution of discharges in a braided channel for activating dying channels were determined.
2.  The regularities of fluid flow at the point of separation were established, which have a substantial effect on the results of calculating the distribution of the discharge in the channels. Detailing of the calculations of the distribution of the discharge in channels by means of the main equation of uniform motion without consideration of the regularities of fluid motion at the point of separation leads to an increase of the deviation of the results obtained from the actual data.
3.  The results of the investigations have importance for developing optimal variants of structures being designed and increasing the reliability of existing structures, for improving the navigation conditions on rivers with an analogous scheme of braiding of the flow, since they reflect the characteristics of the distribution of discharges and velocities in a braided channel under various conditions which are not being taken into account by the existing hydraulic calculation methods.
Translated fromGidrotekhnicheskoe Stroitel'stvo, No. 2, pp. 27–29, February, 1989.  相似文献   

2.
1.  The morphometric method of estimating the geometry of stable canal channels, as based on a deeper physical nature and using the fluvial process theory principle, has become most popular in solving the problem of designing canals in alluvial soil. It can be considered that sufficiently reliable relations have presently been obtained which can be used in practice with consideration of the particular canal operating conditions.
2.  More detailed investigations of the separate consideration of the transport of bottom and suspended sediments on stability for providing channel stability of canals when vvne are needed for refining the morphometric relations.
3.  It is necessary to continue investigations of the effect of the sediment concentration of a flow on the velocity structure of the flow and noneroding velocity.
4.  It is necessary to consider as one of the most important problems of open-channel hydraulics the activation of experimental and theoretical investigations of the three-dimensional turbulent structure of a flow for the purpose of estimating the distributon of local velocities in the flow cross section as a function of the size of the channel and roughness of its walls.
5.  For dynamically stable canal channels investigations are needed for estimating the roughness coefficient as a function of the channel size , shape, sediment concentration of the flow, and bed-load transport.
6.  It is necessary to prepare the relevant materials for compiling standard data on the design of dynamically stable canals.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 3, pp. 37–42, March, 1991.  相似文献   

3.
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   

4.
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   

5.
1.  The actual state of the outlet works as a whole can be evaluated as positive.
2.  To provide complete readiness of the outlet works for service regimes and to keep them in good working order, it is necessary to seal the existing damages and subsequently to carry out annual scheduled preventive maintenance.
3.  Long service of the restored bottom revetment of the stilling basin is possible under conditions of a moderate regime of waste discharges with their uniform distribution over the basin width, shortening of their duration, and reduction of the number of outlets put into operation.
4.  The restored basin revetment is in need of careful observation of its condition and sealing.
5.  The use of outlets for reducing the rate of filling the reservoir and especially for providing navigation releases is not permissible. They should be used only if the discharge capacity of the hydrostation units is insufficient for preventing filling of the reservoir during the spring flood above the elevation of the NPL as well as for not exceeding the NPL during passage of the summer-fall freshets with the reservoir filled to the NPL.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 4, pp. 9–12, April, 1994.  相似文献   

6.
1.  Despite their openness, transverse discontinuous structures have a jetty effect.
2.  Discontinuous structures formed by two rows of rectangular support masses connected by longitudinal beams have the strongest effect on the dynamics of a pebble beach.
3.  It can be recommended to use circular supports with a diameter of not more than 2 m arranged in one row at a distance of at least 6 m from one another for constructing hydraulic structures intersecting pebble beaches.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 5, pp. 23–25, May, 1989.  相似文献   

7.
1.  Sludge storage ponds can be located on any foundation soils, but economic calculations should be made for selecting the site.
2.  In the presence of seismic conditions, it is necessary to remove weak soils within the shoulder in order to provide its stability with a steepness of the downstream slope up to m=5. Other methods providing stability of the shoulder can also be used with appropriate technical and economic substantiation.
3.  The stability and possible liquefaction of soils of the shoulder should be determined only according to the guide Consideration of seismic loads when designing hydraulic structures, which is the only standard with respect to this problem.
4.  The size of the hydraulic-fill beach is determined on the basis of the particle-size distribution of the slurry.
5.  The permissible minimum width of the hydraulic-fill beach is determined on the basis of calculating the stability of the shoulder.
6.  It is necessary to recommend the construction of a siphon intake (discharge) located on the bank of the settling pool, which gives a more reliable and economical solution.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 12, pp. 53–55, December, 1991.  相似文献   

8.
1.  The suggestions on calculating the strength of concrete joints with transverse reinforcements were made on the basis of using the method of secondary stress fields and permit more complete consideration of the effect of the characteristics of the stress state on the strength of massive members.
2.  Unlike the preceding developments, the present suggestions make it possible to evaluate the reinforcement and concrete strength of the structural member being designed with pin resistance of the transverse bar reinforcement to the effect of the initial and secondary shear stresses in the longitudinal joint.
3.  The installation of an additional amount of transverse reinforcement precludes the probability of separation of the massive member along the longitudinal block joint and provides reliable and safe operation of the structure.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 3, pp. 46–49, March, 1990.  相似文献   

9.
1.  The effect of an inclined face on the stress state of concrete and reinforcedconcrete members was investigated. It was established that shear stresses are a function not only of the transverse force but also of the bending moment and slope angle of the face.
2.  Calculations showed that the presence of an inclined face favorably affects the character of the distribution of shear and principal tensile stresses, as a result of which it is possible to reduce the amount of reinforcement installed for absorbing the principal tensile stresses.
3.  It is recommended to supplement the points of the design standards related to calculation of members on the basis of principal tensile stresses with respect to consideration of the effects of the slope of the face for the appropriate class of members.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 6, pp. 48–50, June, 1992.  相似文献   

10.
1.  The plant manufacturer's power and efficiency guarantees are fulfilled.
2.  The power performance curves obtained for the hydraulic unit at four heads make it possible to select the makeup of operating units that will deliver maximum economy with the load distributed between the units.
3.  In operating the hydraulic units, special attention should be given to adjustment of the combiner curves in connection with the fact that its mismatch downgrades not only the economy of the hydraulic-turbine operation, but also the vibrational state of the hydraulic unit.
4.  Measurements of the vibration levels of the hydraulic units under several heads made it possible to determine the boundary line with respect to power over the entire range of operating heads.
Translated from Gidrotechnicheskoe Stroitel'stvo, No. 4, pp. 26–30, April, 1991.  相似文献   

11.
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   

12.
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   

13.
1.  The accuracy of modeling the velocity field depends heavily on the orthogonality of the grid being generated. Deviation from orthogonality even by 10° increases the ductility of the scheme markedly.
2.  It is necessary to relate bottom erosion not only to the tangential stresses on the bottom, but also the distribution of the kinetic energy of turbulence along the bottom.
3.  In studying channel deformations, a diffusion model with a terminal velocity is most effective, among other things, because it does not include difficult-to-determine diffusion coefficients that enter into a semi-empirical model.
4.  It is better to establish the adhesion condition, and not the reflection condition on the bottom for descending particles — this perceptibly changes the velocity of the bottom forms and their transformation.
5.  A change of ±50% in the transfer frequencies ik that enter into the diffusion model has virtually no effect on the computed deformation of the bottom.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 11, pp. 42–45, November, 1990.  相似文献   

14.
1.  Investigations showed that when constructing dams of fine-grained silty soils by hydraulic filling, it is expedient to use the technology of layerwise placement of soil with consolidation of each layer.
2.  Dependences are given for calculating the thickness of the layers and period of consolidation of the soil on the basis of investigations of the dynamics of the hydrophysical properties of these soils in relation to technological factors.
3.  Dependences are also proposed for predicting the density of the hydraulic-filled soil during construction, as well as the distribution of soil in the profile of the structure.
4.  A method is proposed for calculating the technological parameters, in particular, the rate of construction of hydraulic-fill structures, calculating the size and number of the hydraulic-fill plots referred to one dredge, and prediction of the seepage discharge into the foundation of the dams during their hydraulic filling.
5.  The proposed calculation methods make possible a more substantiated approach to the design of hydraulic-fill structures of fine-grained silty soils and technology of their construction.
Translated from Gidrotekhicheskoe Stroitel'stvo, No. 6, pp. 5–9, June, 1990.  相似文献   

15.
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   

16.
Thus, taking the following measures can be recommended for effective solution of the problem of preventing fouling of generator parts with oil:
1.  The enlistment of skilled specialists for evaluating the design of the installed seals from the viewpoint of current information about the distribution of air streams in the generator.
2.  Inspection of the seals of oil baths, determination of the places of leaks through existing loose fits, bolts, flange connections, etc.
3.  Conduction of tests for determining maximum vacuum zones and for a comparative analysis of pressures in and outside an oil bath.
4.  The development of an active protection system with withdrawal of oil vapors into the maximum vacuum zone to prevent steaming.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 22–26, August, 1995.  相似文献   

17.
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   

18.
1.  The rock foundation of the Sayano-Shushenskoe dam is inhomogeneous in its seepage characteristics: individual stretches in zones of tectonic crushing of the rock are the most permeable.
2.  The depth of opening of the rock-concrete contact does not exceed 27 m.
3.  During 4 years each subsequent filling of the reservoir to the NPL intensified the degree of decompression of the foundation, involving the deep curtain in this process. Signs of cracking of the middle part of the grout curtain were detected.
It is necessary in the very near future to take measures to suppress seepage through the rock foundation.  相似文献   

19.
1.  The development of an ATDS should be realized individually for each operating station with consideration of the design characteristics of the units and should be aimed at solving one of the most important problems of increasing the operating reliability of the main equipment and economy of operating the hydrostation.
2.  The deterministic approach to compiling technological diagnostic algorithms makes it possible to use the operating experience gained and to make the diagnosis on the basis of the actual technical state of the units of the hydrostation.
3.  The ATDSs should satisfy the requirements of prompt, integrated, automatic, and dynamic performance (possibility of the modular buildup of problems being solved as a result of developing new diagnostic means and methods).
4.  The proposed development of an ATDS at the unit level should be done with the possible prospects of inclusion in the PCS of the hydrostation.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 43–48, October, 1990.  相似文献   

20.
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   

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