Zone 3b resists water pressure and controls face deflection. In most applications, commercial tools that combine features of these. Figure 6 shows that the safety factors of the downstream slopes of concrete faced rockfill dams range from 1. References required and related publications are listed in appendix a.
The paper provides an outline of important points that need to be recognized and understood when selecting material for use in embankment dams. Zone 2 support the concrete faces processed granular materials. A study on concrete faced rockfill dams usq eprints. The stress and deformation conditions of cfrd are absolutely critical for the safety of dam. Roller compacted concrete dam i examensarbetet kallat rccd och en concrete face rockfill dam i examensarbetet kallat cfrd. Hydropower is often used in conjunction with dams to generate electricity. Concrete face rockfill dams cfrds are gaining a worldwide recognition as. Free board vertical distance between the crest of embankment excluding camber and still reservoir water surface.
Concrete face rockfill dams 1st edition paulo teixeira. This is the category for concreteface rockfill cfrd dams. Behavior of concrete faced rockfill dams and assesment of current analysis methodologies erdogan, emrah ergan m. Constructing concrete faced rockfill dams cfrds with weak rocks has great advantages as a result of the use of local materials, costeffectiveness, extensive adaptability, simple construction. In particular, the concrete faced rockfill dam cfrd is one of the most promising dam types for this region, since it can make full use of local materials to reduce the transportation of construction materials out to the dam site, and has high adaptability, distinct economic advantages, and an excellent capability for earthquake resistance. Reliability analysis of high rockfill dam stability. Figure 4 shows the configuration of the selected dam. Experimental studies by janbu have shown that the relationship between initial tangent modulus and confining pressure may be expressed as. The cfrd is considered to have high fundamental safety, especially against strong earthquake shaking, and to be appropriate. Factors to be considered for freeboard wave height and wave length height of.
Introduction concrete face rockfill dams cfrds are gaining a worldwide recognition as the most economical type of dams to be constructed in extreme northern and subantarctic regions. In particular, the concretefaced rockfill dam cfrd is one of the most promising dam types for this region, since it can make full use of local materials to reduce the transportation of construction materials out to the dam site, and has high adaptability, distinct economic advantages, and an excellent capability for earthquake resistance. Concrete faced rockfill dams cfrds are wellestablished dam type popularly used because of its ease in construction, low cost, and stability. The university of new south wales school of civil and environmental engineering bibliographic data sheet issn 0077880x 1. Concrete face rockfill dams 1985 edition open library. At the same time, both quantities decrease as the slope ratio parameter decreases. A transition zone consists of smallersize rock is provided between the concrete face slab and the rockfiil. Dam modeling a concrete faced rockfill dam, taken to be 100 m high with upstream and downstream faces inclined at a slope of 1.
Introduction concrete faced rockfill dams cfrds are one type of embankment dams that are built with compacted rockfill in layers or lifts and covered with concrete slabs at the upstream face as part of an impermeable. Concrete face rockfill dams cfrds are gaining a worldwide recognition as the most economical type of dams to be constructed in extreme northern and subantarctic regions. Rockfill dams are a kind of dam that combines porous yet firmly packed gravel, sand, or silt in one section with an area of concrete, metal, clay, or some other substance that completely blocks water. Since 1985 a number of cfrds have been constructed comprising compacted rockfill, with a semipervious filter grading face zone, monolithic face slab, dowelled and grouted toe slab plinth, and. The concrete face will transfer the water pressure to the rocks and finally to the dam foundation. He worked for a number of local project companies before joining dolsar. Cooby dam is a 32 m high concrete faced rockfill dam constructed in the 1930s. Reservoir interaction and foundation effects have been taken into consideration. Construction of concretefaced rockfill dams with weak. Monitoring of dam behaviour was done by 390 sensors with data acquisition system. Particle flow code pfc simulation is analyzed based on the shaking table test, which overcomes the deficiency of macrocontinuity assumption in continuum mechanics and can demonstrate the. The section of compacted granular soil helps slow the flow of water while the impervious zone provides strength and stability. The solid head or massive buttress dam is the most prominent modern variant of the type, and may be considered for conceptual purposes as a lightened version of the gravity dam.
Computation analysis of concrete face rockfill dam under static. The concretefaced rockfill dam cfrd is a widely applied geotechnical structure. Technical progress on researches for the safety of high concrete. The ussd committee on materials for embankment dams has prepared this white paper on materials for embankment dams. Pdf an increasing number of dams are being built on deep sand and gravel foundations. These dams were timber faced, having heights up to 25 m. Combining with engineering practice, research results provide a useful. Specification for concrete face rockfill dam construction. Besides the rockfill embankment and the concrete curtain cfrds.
Chinas first concrete faced rockfill dam cfrd was at kekeya. Pdf behaviour of concreteface rockfill dam on sand and gravel. Concrete face rockfill dams, 2010, 406 pages, paulo. The first rockfill dam known to use concrete facing was chatworth park dam which was constructed in. Jun 06, 2006 constructing concrete faced rockfill dams cfrds with weak rocks has great advantages as a result of the use of local materials, costeffectiveness, extensive adaptability, simple construction, and short construction period.
The concrete faced rockfill dam cfrd was used with increasing frequency in recent years, in many parts of the world. Analysis of stress and deformation of rockfill and concrete. Described is the computation analysis of the concrete face rockfill dam under static and seismic. The intuitive use by knowhow in rock blasting works led oftenly to the construction of timber face rockfill dams, to store water for the sluicing operations. The physical properties of main rockfill can be found elsewhere kong and zou 1999. Pdf design considerations of concrete face rockfill dam with a. A general designation of a type of dam body filled with rockfils or gravels compacted in layers, and also with its face slab as a antiseepage system. Maximum cross section and its finite element discretization are shown in fig.
June 2012, 64 pages cfrd concrete faced rockfill dam construction becomes more frequent recently. Uses, application, and considerations of a rockfill dam. Pdf construction of concretefaced rockfill dams with. It is shown that the rockfill deforms under the water pressure and weight, and the concrete face is compressed. Concrete face rockfill dams 1st edition paulo teixeira da. The techniques combine the use of robotic total stations rts and global. However, in strong seismic regions, earthquakes may cause substantial damage to cfrds or even cause them to fail, thus endangering lives and causing vast property damage and. In china, many concrete faced rockfill dams cfrds with heights over 200 m have been built or designed. A reinforced concrete slab is then constructed at the upstream face of the dam.
The concept of a rockfill dam with an impervious face dates from the california gold rush of the 1860s and 1870s 1. Specification for concrete face rockfill dam construction prc national bureau of energy on. It was therefore analyzed the alternative rockfill solution with a bituminous concrete core. Two kinds of rockfill dams, that is, concrete faced rockfill dams and earth core rockfill dams, are analyzed and their typical crosssectional shapes are shown in figures 4 and 5.
Cooby dam is a 32 m high concretefaced rockfill dam constructed in the 1930s. The concrete faced rockfill dam cfrd is a widely applied geotechnical structure. Ppa 18849 construction of the magwagwa dam multipurpose project along the sondu river in the western kenya region. Construction of concretefaced rockfill dams with weak rocks. Pdf on jan 16, 2019, z erkay and others published design. Concrete face rockfill dam draft cfrd international society hereby organized cfrd experts from relative countries for comprehensive summing up the experiences of constructions of world concrete face rockfill dam cfrd and studied the technical problems occurred recent years in the constructions of world high and very high cfrds, and presented the. Constructing concretefaced rockfill dams cfrds with weak rocks has great advantages as a result of the use of local materials, costeffectiveness, extensive adaptability, simple construction, and short construction period. Contribution for the dissemination of rockfill dam with. Jan 01, 2010 specification for concrete face rockfill dam construction prc national bureau of energy on. Design considerations of concrete face rockfill dam with a high cutoff wall and.
The inherent features of concrete face rockfill dams and the tr end of building higher dams have been recently questioned by three recent incidents where major dams have experienced significant cracking in the central portion of the dam after the first filling. This consulting guide presents details and analyses of twentyeight large crfd dams worldwide. The deformation and contact behavior between concrete face and rockfill are important to the safety of concrete face rockfill dams. Reinforced concrete slabs replaced timber as the impervious element for higher and permanent dams in. Deformation of the nam ngum 2 concrete faced rockfill dam. The dam body consists of a 120m high asphalt concrete core, the upstream and downstream transition layer, the downstream main rockfill zone, and the upstream and downstream secondary rockfill zone. The construction of cfrd involves placing the highergrade rock at the dam core, and compacting them to their maximum strength. Design of earth and rockfill dams design of earth and rockfill dams.
Concrete face rockfill dam compared to roller compacted concrete dam. The conventional method of quality control mainly relies on manual process control and. Cfrd cofferdam compacted rockfill compression concrete face rockfill concrete face slab concrete slab construction copper waterstop core cracks crest deformations downstream face downstream slope earthquake elevation embankment engineering excavation face rockfill dam face slab figure foundation foz do areia. Nam ngum 2 is one of the world ranked concrete face rock fill dam cfrd in lao pdr. Technical progress on researches for the safety of high. The outer slopes both upstream and downstream are 1,4.
Keywords concrete faced rockfill dam, sequential impoundment process, nonlinear finite element method, horizontal and vertical deformation 1. In structural concept the buttress dam consists of a continuous upstream face supported at regular intervals by downstream buttresses. Mar 11, 2020 ppa 18849 construction of the magwagwa dam multipurpose project along the sondu river in the western kenya region. The first rockfill dam known to use concrete facing was chatworth park dam which was constructed in california, in 1895. Analysis of stress and deformation of rockfill and. Rockfill modulus and settlement of concrete face rockfill. The main body of the concrete face rockfill dam consists of a zoned rockfill and a thin concrete slab on the upstream side which provide the watertightness of the dam above the ground together with the perimetric joints and the plinth. Oct 16, 2016 5 treatment of dam foundation and abutments 5. Abstract the focus of the present study of a concrete. Effects of dynamic properties of rockfill materials on.
Concrete faced rockfill dams cfrd have been widely used for multipurposes over the world. A dam is a barrier that stops or restricts the flow of water or underground streams. Pages in category concrete face rockfill dams the following 115 pages are in this category, out of 115 total. The concretefaced rockfill dam cfrd is an important dam type in the. June 2012, 64 pages cfrd concrete faced rockfill dam construction becomes more frequent recently not only because of its secure nature, but also its. This consulting guide presents details and analyses of twentyeight large crfd dams worldwide, including the highest dam in the world. Safety of cfrds depends on the proper design, construction, and monitoring of actual behaviour during the construction and during. Twelve chapters provide specialist information on concepts, desig.
Seepage analysis of concrete face rockfill dam for material. Mitigation measures evaluation for concrete faced rockfill dams. However, much of the design in this sector is still. Introduction rockfill has been used in the construction of dams for over 150 years 1. Deformations of concrete face rockfill dams cfrds resting on soil foundation67 te and al. The displacements of the concrete face during the reservoir filling should not exceed the maximum values allowed in order to maintain its structural integrity. Deformations of concrete face rockfill dams cfrds resting. So analyzing the dam seepage field before and after joint sealing damaged is significant. Both quantities decrease as the dam height increases, as mentioned by cao and chen 1991. Based on the monitoring data of shanxi concrete face rockfill dam, the stress of concrete face, deformation of rockfill and facing joints were studied. To verify the suggested model with other methods in literature, the prediction results obtained for concrete faced rock fill dams is compared with the clement method.
Overview of manual the objective of this manual is to present guidance on the design, construction, and performance monitoring of and modifications to embankment. A concrete faced rockfill dam cfrd has some advantages compared to other. It is shown that the rockfill deforms under the water pressure and weight, and the concrete face is compressed in central and otherwise around abutment during the reservoir filling. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. West seti dam, 190 m in height in nepal kenneally and al. A dam can also be used to collect water or for storage of. The dam height varies from 100 m to 350 m in intervals of 50 m.
Concrete faced rockfill dams, cfrd, is a term used to describe a certain type of dams that is composed by a rockfill embankment with a waterproofing upstream reinforced concrete curtain. Numerical simulation of impoundment process of concretefaced. Numerical simulation of impoundment process of concrete. Concrete faced rockfill dams cfrds zones 1a and 1b protect the upstream concrete faces usually cohesionless silt or fine sand. Concrete face rockfill dam compared to roller compacted. Pfc simulation on shaking table concretefaced rockfill. Mitigation measures evaluation for concrete faced rockfill. A dam body filled mainly with gravels is also called as concrete face gravel dam. Missouri university of science and technology scholars mine. Dynamic damage evaluation on the slabs of the concrete.
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