1. Bakun Dam –Some design and construction challenges
This paper outlines some of difficulties faced and solutions adopted in the design and construction of Bakun, 205m high CFRD, including upstream cofferdam, which was overtopped on numerous occastions during construction.
------------------------------------Tan Yong Long et al Malaysia -----LEa3-7
2. Recent development of CFRD in China
----------------------------Chen Qian China –LEa8-15
3. Cethana dam 30 years on ---recent upgrades
The dam (110m) was successfully designed and built in Australia as well as around world. The dam was well instrumented and results abtained from the dam have proved to be a valuable aid in better understanding the behavior of this type of dam.
This paper summarizes the performance of Cethana dam over the past 3 decades, how the recent upgrades were developed and the construction methodology associated with these upgrades. It is important that when reducing the dam safety risk of a dam, that we don’t expose the dam to a significantly higher risk during the construction of those upgrades. ----------R.I. Herweynen - Australia ----LEa16-24
3. Merowe dam project CFRD of extended length
This paper presents the instrumentation of the CFRD with survey beacons and settlement gauges to control the displacement of the dam and concrete face, and piezometer to monitor and seepage through dam and its foundation. A fiber optical leakage detection system is envisaged to be installed downstream of the perimeter joint over the entire length to detect and leakage through this critical joint but also through the concrete face sealing. different displacements between the concrete slabs as well as between the slabs and the plinth is controlled by the joint meter.
The Merowe Dam has an earth core rockfill dam with a maximum height of 67m and a crest length of 841m, founded on deep alluvium, and 2 CFRD on both river banks. Although the maximum height of the 2 CFRD is 53m only, the dam are of special interest due to their extreme crest length of 1437m respectively. The length od the dams requires special attention in the design and construction of the jpoints.
----------------------------------------------------- Lutz D. Schewe Germany--- LEa25-32
4. Selection design and construction features of the Siah-bishe pumped storage project
Selected design and construction issues of the lower of the two dams which has a height of 101.5m. The project is in a region of very high seismicity and some pertinent design features are presented. Construction faces considerable difficulties with the excavation of (up to 25m) deep overburden in a narrow steep valley and also with the extraction of quarried rockfill of adequate quality.
--------- Kayson Company Iran --- LEa33-39
5. More than 50 years of EDF’s experience in CFRD design and performances
EDF’s experience on the design and performance of CFRDs in France is presented
With several dams built nad operated for more than 50yearsin the Alps and Pyreneases mountains , most of them in cold weather conditions (La Sassiere, La Coshe， Greziolles)
and on the works conducted on dynamic analysis and long-term behavior based on experience and basic analysis of the large seismic events monitored for the COGOTI dam in Chile.
------------------Franc. Ois Delorme et al France --- - LEa40-48
6. Application of new technologies in Shuibuya CFRD
The 233 m high Shuibuya CFRD is the highest one of its kind in the world. In order to resolve numbers of key technology issues effectively and to improve the dam performance both in safe and economy, many new concepts , new technologies , new materials and new process have been applied in its design , construction, and safety monitoring , which are summarized in this paper to serve as a useful reference for the further development in the design, construction and safety monitoring of CFRDs.
------------------------------------------Sun yi et al China -- LEa49-57
7. Planning, design, and construction aspects of Dhauliganga CFRD founded on deep alluvium
Dhauliganga dam is 56m high CFRD founded on deep alluvium of 70m thick overburden in the river bed with pebbles and bounders presenting ruled out excavation upto final rock end and hence the layout with a CFRD with an upstream plastic concrete 70m deep cut off wall was adopted. Planning, designand construction of cut of wall has been challenging. The special details of joint between cut off wall and the plinth , and plinth and face slabs are interesting.
--------------------S.P. Sen et al India – LEa58-62
8. Empirical design of CFRD and numerical modeling
This paper acknowledges the fundamental need for an empirical design , but uses numerical modeling techniques to explore particular area of the behavior of the rockfill to complement the empirical design and hope that the great deal of efforts having been spent in numerical modeling of CFRDs to contribute to its further development.
---------------------Rori Green et al USA – LEa65-68
9. Design aspects of cutoff wall for CFRD located on thick alluvium soil layer
The design aspects of a cut-off wall for a concrete face rockfill dam located on a thick alluvial soil layer are discussed in the present paper. The static deformation behaviour of the cut-off wall made of plastic concrete is compared with that of a normal concrete cut-off wall. The effect of frictional sliding along the upstream and downstream interfaces between the cut-off wall and the alluvium was also investigated. The results of the analysis show that the plastic concrete cut-off wall effectively sticks to the alluvium on the downstream side. In contrast, if the cut-off wall would be made of normal concrete, a large slip displacement would occur between the top of the cut-off wall and the alluvium on its downstream side, as normal concrete is very stiff compared to the alluvium. Such a large slip cannot be easily accommodated by the joint between the cut-off wall and the plinth slab. A seepage analysis was also performed to study the influence of the depth of the cut-off wall on the seepage flow. The results show that a full cut-off wall penetrating into the rock stratum is desirable. However, a partial cut-off wall would still be acceptable.
--------------- Sujan Malla and Martin Wieland Switzerland ------- LEa69-78
10. Rockfill Design and Construction of the Bakun Dam
Fresh and slightly weathered hard rock materials are scarce at the site of the
------------- Tan Chuan Ngan et al Malaysia ------ LEa81-91
11. Construction of new rockfill dams with geomembranes
Synthetic geomembranes have been adopted to provide the watertight element in embankment dams since 1959. The liner most commonly used is a PVC geomembrane coupled to an anti-puncture geotextile. Having high elongation at break, PVC geomembranes can accommodate the differential movements of the dam, especially at intersections with rigid appurtenances. The PVC geomembrane is generally positioned at the upstream face and is anchored against uplift by wind, waves, and fluctuating reservoir levels. The anchorage can be of the mechanical type, along parallel vertical lines (exposed geomembrane), or of the ballast type (covered geomembrane). A dedicated face drainage system allows removing infiltration water, and monitoring the behaviour of the waterproofing system. The paper describes the general concepts, and outlines the latest design developments that allow constructing new and safe rockfill dams in shorter times and at lower costs. The advantages that a geomembrane sealing system can provide in construction of new dams, in terms of capability to resist settlements and environment aggression, and in terms of reduced costs, are discussed.
------------------ Alberto M. Scuero et al Switzerland ------ LEa92-99
12. Construction of new exposed waterstops, and their application to repair of CFRD
The paper illustrates how an exposed geomembrane systems, now patented, used since more than 30 years to waterproof perimeter joints in embankment and concrete dams, was developed to become an exposed waterstop, first for new construction of RCC dams, and then as repair measure for failing joints of CFRD. The exposed waterstop uses a PVC geomembrane with dimensions and tensile characteristics such as to cover the joint and allow bridging openings of the joint largely superior to foreseen opening. The exposed PVC geomembrane is installed over a support layer, and watertight anchored along the perimeter. The paper discusses the concepts, the technical/constructional advantages of the exposed waterstop as compared to the traditional embedded waterstop, and its application to repair failing joints of Strawberry
------------------ Alberto M. Scuero et al Switzerland ------ LEa100-107
13. Construction of Kannaviou Dam –the first CFRD in Cyprus
Discussing the main issues related to the construction of Kannaviou dam, the first CFRD dam in Cyprus.
-------------------Demos Antoniou Cyprus ---- LEa108-113
14. Five high capacity cable cranes for the construction of Xiaowan Dam, China
----------------Ing. Wei Ye Germany ---- LEa114-117
15. Repair of CFRD with synthetic Geomembranes
Ageing of CFRD entails formation of cracks in the concrete face and/or failure of the waterstops. The problem is particularly severe in presence of settlements, frequent freeze/thaw and ice, and is of particular concern in dams located in seismic areas. Increased leakage is sometimes unacceptable for safe operation of the dam. Installing an impervious synthetic geomembrane over the upstream face allows stopping leakage, monitoring the efficiency of the new waterproofing lining, and restoring the dam to safe operation. The flexible geomembrane at the upstream face of the dam is capable of accommodating the movements that may still occur at the existing discontinuities (cracks, failing joints), and of resisting demanding service environments. The paper illustrates the most used system, adopted since the late 1970s, and the most recent case histories related to two CFRD repaired in 2004 with exposed geomembrane (Salt Springs in USA,
----------- Alberto M. Scuero et al Switzerland ---- LEa121-127
--------Ahad Bagherzadeh_Khalkhali, IRAN ---- LEa137-146
18. EARTHQUAKE ASPECTS OF CONCRETE-FACE ROCKFILL DAMS, DIAPHRAGM WALLS AND GROUT CURTAINS
Concrete-face rockfill dams have become attractive alternatives to large conventional clay-core embankment dams because of their considerable economic benefits. However, these dams create also new risks, as their performance under extreme actions and events is not known properly. This applies in particular to the earthquake safety, which has to be guaranteed for the strongest earthquake that might affect a dam site.
A qualitative assessment of the seismic performance of concrete-face rockfill dams under strong ground shaking is presented and possible problems and deficiencies are discussed.
In the case of CFRDs some aspects related to the concrete face have been identified, which need further investigation. This applies in particular to the in-plane stresses in the concrete face caused by the earthquake ground motion in cross-canyon direction. This may lead to joint damage, local buckling of the concrete slab or other local damage due to high stresses.
Finally, possible scenarios of the seismic performance of grout curtains and diaphragm walls are also given and it is pointed out that these often neglected elements have also to be considered in the overall seismic design of a dam as damage caused to these elements may have detrimental effects on the overall safety of the dam after a severe earthquake.
--------------Martin Wieland Switzerland --- LEa149-155
----------------Markus Aufleger Germany -- LEa156-162
20. A Modular Low-Power Data Acquisition Architecture for Dam Safety Monitoring
The paper reports on a new data acquisition architecture for use in dam safety and hydrological monitoring. The architecture is optimized for economically reaching widely scattered measurement points in outdoor, remote locations, which have historically imposed challenges in both initial system design as well as long-term maintenance.
The new architecture is based on Geomation’s experience of more than 20 years of data acquisition for structural behavior monitoring on dams. It takes advantage of the latest technological developments driven by large industrial and consumer markets related to portable electronics, communication protocols, license-free radios and process monitoring software. The new architecture is further based on industry standards that have been adopted on a global level. The result of compatibility with these standards in the new architecture is a reduction of risk and cost for end-users and system integrators alike.
The newly introduced line of products is based on extremely low-power Remote Terminal Units (RTUs) that can be deployed in the field. The RTUs each communicate with remote Input/Output (I/O) Assemblies. The communication link between the RTU and the I/O Assemblies can be cabled-extended or radio-extended, using low-power license-free spread spectrum radios, allowing I/O Assemblies to be located close to points of measurement. The RTUs communicate with a Host computer using a variety of high-speed communication links, such as license-free spread spectrum radios, fiber optic modems, and digital wireline links, thus resulting in a message-efficient two-tiered communication link between the Host computer and the I/O Assemblies to which the instruments are connected. Connections to RTUs through public telephone and satellite links are also supported.
This unique architecture allows the elimination of extended instrument cable runs on or near the surface of the dam. In addition to minimizing the most significant site preparation costs, which results from the elimination of horizontal instrument cable runs, the main advantage is to virtually eliminate the risk of lightning damage to the instruments and to the data acquisition hardware. Damage from high voltage transients generated in long horizontal cables running parallel to the ground surface have been the cause of numerous instrument and measurement system failures in the past, and is the most significant impediment to sustained reliability.
------------------- J.M. Klebba USA. -- LEa163-168
21. Deformations and cracks in CFRDs
This paper presents the design and construction features of Concrete Face Rockfill Dams, comments about rockfill zoning and performance during construction and after reservoir impounding and outlines some comments related to the cracking phenomenon and abnormal recorded leakage after reservoir impounding. Some aspects of plinth design and construction concerned with plinth geometry and alignment at abutments are evaluated in view of recent abnormal situations reported in current CFRD dams. The rockfill constructing planning in several phases with high monthly average pick production and downstream shell deformation and its effects in dam behavior, are presented and discussed in this paper. The influence of the valley shape- factor in rockfill deformations is also analyzed in a retrospective.
-----------------Manoel de Souza FREITAS Brazil -- LEa169-176
22. Dam Monitoring Using Long SOFO Sensor
In order to increase the safety of civil engineering structures many different monitoring systems have been developed. The majority of these systems are based on the measurement of the deformations, the displacements or the strains of the structure.
The SOFO system is based on low-coherence interferometry in single-mode optical fibres and allows the measurement of deformations in civil structures with a resolution of a few micrometers and an excellent long-term stability. SOFO allows permanent, automatic and reliable monitoring and has been successfully tested in different types of structures such as bridges, tunnels and geostructures worldwide.
The gage length of the standard SOFO sensors varies between 200 mm and 10 m. Monitoring of the large structures, such as dams or tunnels, requires however the use of sensors with a base length of several tenths of meters. To create such a sensor, certain modifications of the existing (standard) sensor are required. The long sensors with gage length of 30 m was designed, assembled and installed in the Emosson dam in Switzerland. It was compared with a parallel rod extensometer during two years. The results indicate excellent agreement between the two systems and prove the soundness of the long sensor design.
------------------B. Glisic et al Switzerland -- LEa177-184
23. 3D Seepage Computation and Analysis of Bakun Dam Area in Malaysia
The Bakun Hydropower Project is situated on the Balui River, a tributary of the Rajanj River that stretches in the eastern part of Central Sarawak, about
and humidity characterize.
------------DUAN Xiangbao China -- LEa185-191
24. Three Dimensional Dynamic Analysis Of CFRDs
In this paper a part of research about two and three dimensional (3D) seismic behavior of CFRDs has been presented.
In this respect using ANSYS finite element program and elastic and elasto-plastic models for rockfill material, static and dynamic analyses have been performed and effects of stage construction of dam body and water level of reservoir (full or empty) have been considered as well.
Peak horizontal acceleration and displacement, in addition to peak shear stress and strain of different points of dam body and peak horizontal acceleration and displacement, and principal stresses of face slab, were compared for two dimensional (2D) and 3D cases.
-------------Shahab Esmaeili Iran -- LEa192-201
25. Effects of dam foundation interaction and special variable ground motion on seismic response of CFRD
Dynamic analysis of a typical 3D CFRD in a prismatic canyon with trapezoidal cross section is reported in this paper. A new approach based on scaled boundary finite element method is used to obtain scattered motion along canyon and also dam—abutment interaction analysis Results of the analysis indicate that dam body and slab displacement as well as slab internal loads are increased due to out of phase motion abutments, however, they are decreased by consideration of dam –foundation interaction.
---------------S.M. Haeri Iran -- LEa202-210
26. Applicable research on polyacrylonitrile (Pan) fiber in CFRD
---------Zhang Haiwen China - LEa211-217
27. Influence of construction of CFRD on concrete slabs
-----------Yoshiyuki Kaneko Japan - LEa218-225
28. Research on properties of face fiber reinforced concrete of Shuibuya
-------------Li Jiazheng China - LEa218-225