This Standard specifies the design principles， technical requirements and calculation methods for concrete face rockfill dams.
This Standard is applicable to the design of the concrete face rockfill dam (hereinafter referred to as CFRD) of grades 1， 2， 3 and grades of 4 and 5 with a height of above 70m in water conservancy and hydropower projects. It includes the layout of embankment and plinth， embankment materials and zoning， face
slab and its water stop system， dam foundation treatment， dam calculation， flood protection during construction， stage construction and anti-seismic measures， monitoring， etc.
For the design of grade 4 and 5 CFRD with a height of less than 70m， this Standard may be referred to.Special studies are needed for the design of CFRD with a height of over 200m.

Foreword
1 Scope
2 QuotedStandards
3 General
4 Terminology and Symbols
5 Dam Layout and Zoning
6 Embankment Materials and Specification for Compaction
7 Plinth
8 Concrete Face Slab
9 Joints and Water Stops
10 Dam Foundation Treatment
11 Dam Calculation
12 Anti-earthquakeMeasures
13 Heightening of Dam and Stage Construction
14 SafetyMonitoring

《Design Specification for Concrete Face Rockfill Dams》：
10.1.1 The foundation face of plinth shaU be made in accordance with Clause 7.1.1.
10.1.2 The excavated face for plinth foundation shall be made smooth without scarps and adverse slope. The adverse slope and scarps interfering the compaction of cushion material shall be cut off or backfilled with concrete, or the plinth may be relocated, if necessary.
10.1.3 The upstream bank slope above the plinth elevation shall be designed as the permanent slope.
10.1.4 When excavating upwards-slope immediately downstream the plinth area, the excavation slope shall be flatter than that of face slab; when cutting downwards-slope immediately downstream the plinth area, the slope shall not be steeper than 1:0.5.
10.1.5 A rockfill dam may be built on weathered bedrock, the deformation modulus of bedrock shall not be less than that of the embankment. The embankment foundation at the plinth downstream, within the range equal to 0.3~0.5 of the dam height,is preferable to be of low compressibility. Neither adverse slope
interfering compaction nor scarp steeper than 1:0.25 is allowed on the foundation after excavated. The restriction on compressibility for other downstream foundation may be relaxed, only the stability of excavated slope shall be ensured.
10.1.6 When valley slopes are rather steep, the excavated slope on both banks upstream of the dam axis shall be specially studied together with the arrangement of low compressibility area in the embankment.
10.1.7 The excavation of sand/gravelin dam foundation shall be investigated, tested and evaluated carefully and then determined.
10.2 Treatment
10.2.1 When poor geologic conditions are encountered in bedrock where the plinth is located, such as fault, fracture zone or weak intercalation, the permeation, seepage deformation and erosion impact on dam foundation shall be studied in light of the attitude, magnitude and the nature of composed materials so as to determine the allowable hydraulic gradient for bedrock under plinth and the measures of seepage control and corresponding treatment, such as: concrete plug, cutoff, extension of plinth width,or putting impervious plate at downstream and setting filter protection at upstream and downstream, etc.
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