1. Bituminous-faced Rockfill Dam Seismic Performance Prediction of stress-strain behaviour and potential damages
Proposal for the 15th International Benchmark Workshop on
Numerical Analysis of Dams
Proposers: A. Vecchietti 1 , G. Russo 1 , S. De Marco 2, A. Fiorino 2, M. Cecconi 3, V. Pane 3, G. Mazzà 4
1 University of Cassino & Southern Lazio, Department of Civil and Mechanical Engineering
2 So.Ri.Cal Spa
3 University of Perugia, Department of Engineering
4 ICOLD, ITCOLD & RSE Spa

2. Menta Dam

3. Menta Dam Max. Elevation: 89.75 m (crest elevation: 1431.75 m a.s.l.)
Menta Dam is a Bituminous-faced rockfill dam (BFRD)
Max. Elevation: m (crest elevation: m a.s.l.)
Slope: :1.8 (downstream face has 2 berms at Elev and m a.s.l.)
Crest Length: 450 m (325.0 m main valley m «selletta»)
Top Width: 10 m
Storage:
1.8×107 m3
Water: Level Elev.
m a.s.l. (min. WL)
m a.s.l. (retention WL)
m a.s.l. (max. WL)
main embankment
«selletta»

4. Menta Dam
Plan view
Longitudinal section
main embankment
«selletta»

5. Menta Dam Cross-sections Sez.2 Sez.1 Sez.3 Sez.4 Sez.4 Sez.1 Sez.3

6. Menta Dam Cross-section (elements) Rockfill embankment (dam body)
Bituminous concrete facing - guarantees the impoundment of the reservoir
Foundation is made of metamorphic fractured rock
Cement-water injections reaching a depth of about 50 m - create a grout curtain
Draining layer at dam-foundation interface - prevents ∆u in the embankment

7. Central Italy earthquake (2016 sequence)
Objective
Main objective: evaluation of the embankment stress-strain behaviour under seismic conditions
Seismic scenario: ag = 0.45 g, n.2 time series recording as input
The impoundment level to be considered is m a.s.l.
Friuli earthquake (1976)
Central Italy earthquake (2016 sequence)

8. Methodology Requirements:
Analyses must account for stiffness dependence on shear strain levels (G-γ) and hysteretic damping, typical of soil dynamic behaviour
The comparison of results will allow the evaluation of different rockfill constitutive models response
Assumptions:
Plane strain (2-D) numerical simulations
dam body can be considered homogeneous
embankment piezometers support the ∆u = 0 hypothesis

9. Methodology Available data:
Results from in situ and laboratory tests on rockfill samples

10. compressive strength , fc (kPa) tensile strength, ft (kPa)
Methodology
Available data:
Foundation rock-mass
Bituminous facing
γ (kN/m3)
E (MPa)
ν (-)
k (m/s) 27
7×103
0.25
1.0×10-7
γ (kN/m3)
E (MPa)
ν (-)
k (m/s) 24
150
0.44
impervious
compressive strength , fc (kPa)
tensile strength, ft (kPa)
1490
950

11. Results
Aims:
Deformation patterns of the embankment at the end of the dynamic simulation:
crest settlements,
permanent displacement profile of the axis of the dam,
strain contour plot …
Stress states and Stability assessment (proximity to failure)
(optional) Assessment of seismic behaviour of the bituminous facing by analysing potential damages and cracking of the upstream face
Expected working time:
2-3 weeks

12. Proposers: S. De Marco, A. Fiorino _ So.Ri.Cal Spa
G. Russo, A. Vecchietti _ University of Cassino & Southern Lazio, Department of Civil and Mechanical Engineering
M. Cecconi, V. Pane _ University of Perugia,
Department of Engineering
G. Mazzà _ ICOLD, ITCOLD & RSE Spa