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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These suggestions should be analyzed for each case. Click here to sign up. Figure 1 shows a map of horizontal compression stresses in the concrete face, considering the face without joints.
Flávio Alberto Crispel
These minimizations are so more expressive as smaller are the widths of the slabs. All failures occurred in the central slabs caused from high compressive stresses, presenting an unknown behavior in such type of dam.
These modifications were successfully introduced in dams built race Brazil and in the world; however, all of them with height below m the height of Foz do Areia dam. Dd Center Find new ed papers in: 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.
The endocamento should receive continuous analysis to allow the necessary actions in the design and in the constructive methods. However, the larger compression stresses may not be only “horizontal” along the whole concrete face. Enter the email address you signed up with and we’ll email you a reset link. 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.
The basic principle stated by Cooke – Ref. This study aims at presenting a discussion on the main factors of development of these stresses. 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. 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 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.
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, fade clay fill on the perimetral joint.
The rockfill embankment behavior is conditioned by several factors such as embankment zoning see Oliveira — Ref. This would be an acceptable approach for CFRDs have intrinsic stability in function of the following features: Compressive joints should be used in a way to allow the movement of the central slabs and relieve the compressive stresses among them. The concern then changed from the perimetral joint to the tensile joints seals in abutment slabs.
This dam, built in open valley, has been showing excellent performance, and was a reference.
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.
Barry Cooke died in This prediction must take in place the geological-geotechnical features, the shape and topography of the valley and the properties of available construction materials. It is worth repeating the technical contribution of Mr.
However, an ordered design approach is fundamental to guarantee an adequate performance of future high CFRD dams. The instrumentation of the embankment and of the concrete face should be intensified to reflect dam performance, mainly of its singularities. 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 the center of the face.
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 solutions. 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.
Flávio Alberto Crispel
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 to be built. They presented a quite safety behavior fwce, but with significant leakages as they height enrocamentl up to 90m. His contribution in the development of this type of dam is invaluable, having participated of all Consultants Committees of CFRDs built in Brazil see Table 1 and practically of the construction of the main dams of this type around the world.