BARRAGENS DE ENROCAMENTO COM FACE DE CONCRETO PDF
As barragens de enrocamento com face de concreto (BEFC) têm sido construídas com freqüência crescente em todo mundo. Apesar disso, os critérios de. Many translated example sentences containing “barragens de enrocamento” Simpósio Sobre Barragens de Enrocamento com face de Concreto [ ]. 15 out. PERCOLAÇÃO NAS BARRAGENS DE ENROCAMENTO COM FACE DE CONCRETO EM CONSTRUÇÃO – Nelson L. de S. Pinto.
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Log In Sign Up. He received many awards for his brilliant professional performance, such as the Distinguished Engineering Alumnus Award, from the University of Berkeley — California, and the Terzaghi Lecturer offrom the American Society of Civil Engineers. The concern then changed from the perimetral joint to the tensile joints seals in abutment slabs. On the other hand, the tensile joints seals of the slabs on the abutments regions should be capable to absorb the largest displacements resulting from the compression of the joints in the central area.
This model doesn’t consider the joints between the slabs of the concrete face.
REFLECTIONS ON NEW DESIGN OF VERY HIGH Concrete face rockfill dams | Ciro Humes –
This problem was solved in further dams by changing the zoning of the fill material in the region of interest and new design of the perimetral joint, which had more than one sealing element and, as an additional defense line, when viable, a clay fill on the perimetral joint.
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Skip to main content. The results should receive continuous analysis to allow the necessary actions in the design and in the constructive methods.
This dam, built in open valley, has been showing excellent performance, and was a reference. However, the larger compression stresses may not be only “horizontal” cocnreto the whole concrete face.
For a more favorable behavior in relation to these efforts, the concrete face should be divided into panels that can reduce or eliminate some of the soliciting efforts above mentioned. Compressive stresses in the concrete face with 4 Joints MPa These results show that compressible joints are effective to avoid the development of high compressive stresses.
Cracks may occur barragfns the concrete face; they would be tolerable since the embankment resists to the flow and the cracks can be easily sealed by placing fine material sandy silt. Numerical model analyses were done to predict probable displacements of the concrete face, which were then imposed to the slabs to obtain the respective stresses. All failures occurred in the central slabs caused from high compressive stresses, presenting an unknown behavior in such type of dam.
It is enrocmaento repeating the technical contribution of Mr. In other cases, leakages occurred by the failure of water stops due to excessive deformation.
These dams, however, presented serious leakage and maintenance problems. These barrageens are so more expressive as smaller are the widths of the slabs. Click here to sign up. In the decade of the of Foz do Areia Dam, in Brazil, was built with m of height, at that time the largest in the world.
Wetting of all the materials and enrocamenot every zone should be done, not only in the upstream third, as usual. Such major infiltrations were barrages to excessive displacements of the slabs in relation to the support plinth, whose perimetral joint was not designed to bear such displacement.
These modifications were successfully introduced in dams built in Brazil and in the world; however, all of them with height below m the height of Foz do Enrovamento dam.
These suggestions should be analyzed for each case. The instrumentation of the embankment and of the ccom face should be intensified to reflect dam performance, mainly of its singularities.
Compressive joints should be used in a way to allow the movement of the central slabs and relieve the compressive stresses among them. Help Center Find new research papers in: This model must be enrocsmento, not only to define the zoning of the embankment as well as future adjustments, in function of the monitoring during ebrocamento construction.
For this goal, studies should be developed with numerical models to estimate, from the very fom of the design, the displacements and stresses in the dam. Except for the Salvajina dam, the others were built in narrow valleys.
Due to the result of the computations, double reinforcement mesh was adopted in large portion of the concrete face, contrary to the usual practice of using a single mesh in barrgaens center of the face. It must be pointed out that this feature is critical on abutments. From toafter the good behavior observed in six dumped rockfill dams belonging to Pacific Gas and Electric Company USAwith heights between 23 and 45 m, higher dams were built, among them are the Salt Springs Dam USA and Paradela Dam Portugalwith heights of and m, respectively.
This study aims at presenting a discussion on the main factors of development of these stresses. However, an ordered design approach is fundamental to cmo an adequate performance of future high CFRD dams.
Such failures motivated the abandonment of this type of solution for dams until when, with the development of heavy vibrating rollers for compaction of rockfill in layers, high rockfill dams with clay core started conceto be built.
This prediction must take in place the geological-geotechnical features, the shape and topography of the valley and the properties of available construction materials.
Flávio Alberto Crispel
However, it seems that his confidence in the stability of this type of dam regarding its resistance to normal operation loads and to the action of eventual water seepage led to adoption of some practical design criteria not totally applicable in very high dams built in narrow valleys, where stress levels extrapolated the already experienced dom.
Compressive stresses in the concrete face without joint MPa Figure 2 shows a map of the compressive stresses in the concrete face considering compressible joints in the region of the face A notable reduction in the the compressive stresses could be observed. At Campos Novos Dam, built in a narrow valley, the displacements of the superficial benchmarks showed an accentuated move towards the center of cnocreto valley. Figure 1 shows a map of horizontal compression stresses in the concrete face, considering the face enrocamsnto joints.
However, some of these dams presented infiltration problems. Continuous compaction control, through equipments installed in the roller, could be an interesting measure to improve the control of the fill.
The success of these dams, with heights of up to m Chicoasen Dam, in Mexicorestarted the construction of concrete face rockfill dams, attractive for their lower cost and shorter time of construction when local rain fall conditions are restrictive for soil compaction.
They presented a quite safety behaviorbut with significant leakages as they height increased up to 90m. Such width reduction would also restrict the area of the slabs where torsional moments may occur. The basic principle stated by Cooke – Ref.