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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The results should receive continuous analysis to allow the necessary actions in the design and in the constructive methods. Such major infiltrations were associated to excessive displacements of the slabs in relation to the support plinth, whose perimetral joint was not designed to bear such displacement.
Flávio Alberto Crispel
They presented a quite safety behaviorbut with significant leakages as they height increased up to 90m. All failures occurred in the central slabs caused from high compressive stresses, presenting an unknown behavior in such type of dam.
Figure 1 shows a map of horizontal compression stresses in the concrete face, considering the face without joints. It is worth repeating the technical contribution of Mr. Compressive stresses in the concrete face without joint MPa Figure 2 shows a map of the compressive stresses in the concrete face enrocanento compressible joints in the region of the face A notable reduction in the the compressive stresses could be observed.
Flávio Alberto Crispel
barragnes The basic principle stated by Cooke – Ref. 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.
At Campos Ccom Dam, built in a narrow valley, the displacements of the superficial benchmarks showed an accentuated move towards the center of the valley. The concern then changed from the perimetral joint to the tensile joints seals in abutment slabs.
II SIMPÓSIO SOBRE BARRAGENS DE ENROCAMENTO
It also presents reflections for criteria development for future design of very high CFRDs in order to avoid such failures. For a more favorable behavior in relation to these efforts, the concrete face should be enrocajento into panels that can reduce or eliminate some of the soliciting efforts above mentioned. These dams, however, presented serious leakage and maintenance problems.
Continuous compaction control, through equipments installed in the roller, could be an interesting measure to improve the control of the fill. However, the larger compression stresses may not be only “horizontal” along conncreto whole concrete face. 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.
For this goal, studies should be developed with numerical models to estimate, from the very beginning of the design, the displacements and stresses in the dam.
This model doesn’t consider the joints between the slabs enrcamento the concrete face. 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.
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However, an ordered design approach is fundamental to guarantee an adequate performance of future high CFRD dams. Help Center Find new research papers in: The instrumentation of the embankment and of the concrete face should be intensified to reflect dam performance, mainly of its singularities. Thus, progressive modifications were introduced in the CFRD design, among them: These minimizations are so more expressive as smaller are the widths of the slabs.
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 Areia dam. Except for the Salvajina dam, the others were built in narrow valleys. Click here to sign up.
Such width reduction would also restrict the area of the slabs where torsional moments may occur. 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 values.
This would be an acceptable approach for CFRDs have intrinsic stability in function of the following features: 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. Compressive joints should be used in a way to allow the movement of the central slabs and relieve the compressive stresses among them. Enter the email address you signed up with and we’ll email you a reset link.
Barry Cooke is invaluable.
It must be pointed out that this feature is critical on abutments. However, some of these dams presented infiltration problems. In his works, Cooke states that the principle of precedents must be followed, but it cannot be restrictive to the progress, either for the implementation of higher dams or for the adoption of more cost-effective enorcamento.
On the other hand, the tensile joints seals enrocameto 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. Wetting of all the materials and in every zone should be done, not only in the upstream third, as usual. The rockfill embankment behavior is conditioned by several factors such as embankment zoning see Oliveira — Ref.
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.
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