首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 593 毫秒
1.
1.  An analysis of the results of a unique on-site experiment at the Sayano-Shushenskoe dam on regrouting the sites of column and radial joints under practically equal conditions was carried out for the first time in our country. Information about analogous works could not be found in the foreign literature.
2.  The works performed indicate the effectiveness and high performance of the multiple grout outlets designed by Gidrospetsstroi.
3.  Having equal conditions of grouting sites of column and section joints under conditions of the upper pool head (H=60 m), we can say the following:
at a head H=60 m, the predominant opening of column joints compared to the opening of section joints located at the same elevation is observed during regrouting; this may be evidence of the action of the arch effect in a gravity-arch dam already during its construction;  相似文献   

2.
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   

3.
1.  Devices for measuring all dredge operating parameters were developed and tested.
2.  The devices developed are distinguished by simplicity of design, accessibility for manufacture in workshops, their installation and adjustment can be performed by the dredge crew according to the available instruments.
3.  The technical manuals can be sent by the authors by agreement with customers. For concluding an agreement, contact the article's coauthor N. N. Kozhevikov at the address: 105568, Moscow, Chechulin Street, house 22, apartment 22, telephone 308-80-96.
Methods MI 1948 -88can ordered from Hydrotech enterprise at the address: 103062, Moscow, Chaplygin Street, house 5.  相似文献   

4.
1.  The obtainment, as a result of numerous calculations on a computer, of generalized relations of the main indices of the load dropping process in the field TW/Tu–TW/TS makes it possible at the initial design stages to rapidly analyze the decisions made about the parameters of pressure conduits and pump-turbines and regulating regimes.
2.  By virtue of the peculiarities of the universal characteristics of reversible diagonal-flow pump-turbines, the maximum value of the temporal nonuniformity of the operation of the unit during load dropping in real ranges of the constants of inertia of the conduits and unit does not exceed the allowable standard value max=nmax/n0=1.6.
3.  The search for efficient regulating regimes reducing water hammer facilitates the introduction of the new concepts initial and final water hammer and plotting the corresponding zones on generalizing graphs.
4.  Rotating the runner blades of the diagonal-flow pump-turbines along with closing the gate apparatus after dropping the load is favorable for reducing water hammer. In this respect they can be more preferable than reversible mixed-flow pump-turbines for the same values of the heads, TW/TS and TW/Tu.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 1, pp. 23–27, January, 1991.  相似文献   

5.
1.  An intake structure with a closed flow having a vertical axis of rotation contributes to the development of a favorable kinematic structure in the channel, which makes it possible to minimize scouring beyond the structure.
2.  Excedence of the near-bottom average and maximum velocities above the average velocities in the channel comes about atl3.3hc downstream from the axis of the intake.
3.  The magnitude of the ratio of the maximum 1st-percentile and average 50th-percentile flow velocities (v1%/v50%), which characterizes the velocity pulsation, attains values for the undisturbed flow in the near-bottom region at a distancel4.1hc.
4.  Complete equalization of the plan diagram of velocities is noted at a distance (4.9–7.8)hc from the axis of the intake structure.
Translated from Gidrotechnicheskoe Stroitel'stvo, No. 4, pp. 17–19, April, 1991.  相似文献   

6.
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   

7.
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   

8.
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   

9.
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   

10.
1.  The construction of facilities of the southern Yakut hydropower complex, making it possible to bring 23–25 billion kWh of renewable energy resource into the energy balance of the Far Eastern power region, should become one of the strategic directions of power construction.
2.  For further elaboration of the concept of development of the energy base of the Far East, it is necessary in the shortest possible time to work out a Feasibility study of the southern Yakut hydropower complex, in which problems of the organization of construction and social and commercial substantiation should be elaborated; in the latter it is necessary to investigate all possible variants of obtaining such large investments in construction.
3.  The creation of the SYaHPC in the territory of the Yakut ASSR will have great significance for the development of the economy and improvement of the living conditions of the population of the republic. Export of part of the electricity to China will make it possible to reliably and constantly meet (as compensation for the removal of lands) a considerable part of the republic's needs for vegetables and fruits and other goods; it will make it possible to eliminate investing a part of the means and material and labor resources in unproductive and unprofitable agricultural enterprises.
4.  The SYaHPC with partial export of the electricity being generated at its hydrostation, being practically unaffected by inflationary processes by virtue of low operating expenses, under market economy conditions in the future can become one of the most profitable enterprises, a most important object of international and regional economic collaboration in the RSFSR.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 2, pp. 52–56, February, 1991.  相似文献   

11.
1.  When constructing earth dams the inclusion of foreign members in the form of reinforced-concrete galleries, shafts, etc., in the body of the structure is impermissible. It is also desirable to eliminate the construction of a grouting gallery under the dam. The foundation should be grouted either before or after constructing the dam.
2.  Installation of monitoring and measuring equipment for observations during operation must be done after completing construction of the dam. Installation of MME during construction leads to its complete disturbance, holds up the rate of filling, and affects the quality of the works.
It is impermissible to construct concrete galleries on made ground. Elements of the dam should be constructed on a homogeneous foundation.  相似文献   

12.
1.  Blocks in fill experience a maximum force effect under conditions of wave action close to resonance when tan 0(h/gT 2)–1/2=4.4–7, in which case the stability coefficient acquires a minimum value.
2.  Formula (19) recommended for calculating the characteristic size of a block D (or the mass of a block d=0.52 mD3) satisfactorily agrees with the laboratory and actual data and advantageously differs from the suggestions known from the literature.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 7, pp. 18–20, July, 1989.  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.  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   

15.
1.  The problem of energy dissipation of the flow remains one of the most important in constructing high-head hydraulic structures with pulsating loads.
2.  During operation of the world's largest gravity-arch dam of the Sayano-Shushenskoe hydrostation, the energy of the flow being discharged is dissipated by a stilling basin. It was established that the powerful dynamic impulses created in this case originate, among others, from the baffle platform and its foundation. The latter circumstance requires the provision of reliable tightness of the joints between the blocks composing the platform and deep solid transition of the platform with its foundation.
3.  For the first time in domestic hydrotechnical practice fastening of the platform of the stilling basin by means of advance grouting and prestressed anchors installed to a depth greater than 20 m was mastered on the construction of the Sayano-Shushenskoe dam.
4.  Works on the manufacture, transport, assembly, tensioning, and testing PSAs were successfully mastered by the Krasnoyarsk enterprise of Gidrospetsstroi. A number of innovations were introduced at the know-how level.
5.  Passage of the 1992 floodwaters at the elevation of the NPL, after pumping water from the stilling basin, showed the effectiveness of the repair and restoration measures taken, which indicates the correctness of the selected designs, optimal technology, and high quality of the works of Gidrospetsstroi.
6.  An analysis of the strengthening works for high-head structures under analogous conditions permits recommending the following measures for designing and constructing a stilling basin: grouting of the foundation in the region of the stilling basin to a depth of 30–40 m;  相似文献   

16.
1.  Despite the decisions made repeatedly at various conferences and seminars, there are still no scientific design guidelines. As a consequence of this, crucial decisions are made without sufficient substantiation and thorough evaluation of the decisions made.
2.  Research institutes should not be limited to collecting data on settlements and temperature and seepage regimes of dams, but on the basis of data already available should give clear-cut standards and regulations for the design of earth structures in the northern construction-climatic zone.
3.  The construction of transition zones between the rock fill of the downstream shoulder and foundation, drainage blanket, and relief drainage is mandatory in all cases when the foundation is composed of fractured rocks covered by a diverse stratum of loose soils of various origin.
4.  The core-filters-drainage system should be a zone of increased attention when performing works and assigning the characteristics of the soils being placed. As far as possible, it is necessary to change to dam designs with narrow cores protected by transition zones and developed drainage. When constructing such dams in the winter, especially in the case of heavy snow falls, it is easier to check the quality of placing the material in the zone of increased attention — core-filter.  相似文献   

17.
1.  The technology of sealing with the use of grouts with an adjustable fluidity loss time (GAFLT), developed at Gidrospctsproekt and successfully introduced on the construction of the Inguri arch dam, is universal and makes possible high-quality grouting of joints with a high degree of their leakiness.
2.  The new technology has indisputable advantages over the existing technology. It provides a high quality of the work and is cost effective, enabling a substantial reduction of labor expenditures and nonproductive losses of cement.
3.  The GAFLT technology can be recommended for inclusion in building codes and can be used when scaling concrete dams under construction.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 34–37, October, 1990.  相似文献   

18.
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   

19.
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   

20.
1.  An industrial procedure for electrofacing by a powder wire of special composition has been developed to produce a wear-resistant coating up to 5 mm thick on the components of suction dredges. An increase of 4–6 times is achieved in the time to failure of the faced components, while the cost of these operations does not exceed the price of the initial article.
2.  It is expedient to use the facing procedure to strengthen new components under plant conditions and to restore worn parts at the site where the suction dredges are operated. The Scientific-Production Spetsstal' can perform work on electrofacing with the required materials, equipment, and technical accompaniment, and organize the strengthening of components at the plant.
3.  The installation of a three-channel suction dredge with effective water protection of components from abrasive wear while eliminating overflow of slurry into the pump and increasing the efficiency of the unit on the whole is proposed. The proposal is recommended for development and implementation.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 3, pp. 10–13, March, 1995.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号