1. Evaluation of Numerical Models in the Analysis of Pine Flat Dam
Presentation draft Version – June 21,2018
2019 ICOLD Benchmark Workshop
Proposed Formulation
Dr. Jerzy Salamon & Ms Hillery Venturini (Bureau of Reclamation)
Dr. M. A. Hariri-Ardebili (University of Colorado, Boulder)
Dr. Richard Malm (KTH) & Ms Giorgia Faggiani (RSE S.p.A)
July 1, 2018

2. Background 2018 USSD Workshop Lesson Learned:
Evaluation of Numerical Models and Input Parameters in the Analysis of Concrete Dams – Pine Flat Dam Case Study (Linear analysis) [1]
The ultimate goal of analysis was to:
identify key uncertainties causing differences in results
determine the need for future workshops
determine research needs and
develop best practices in the advanced dynamic analysis of concrete dams.
Lesson Learned:
Little is gained if participants analyze identical modes with the same input parameters and get similar answers
Likewise, little is gained if participants perform analyses with widely varying input parameters and get widely varying answers, so that key factors cannot be clearly identified
2019 ICOLD Benchmark Workshop - Formulation

3. 2019 ICOLD Workshop Case Study Selection
Pine Flat Dam is proposed for the case study during the ICOLD workshop
The dam is located east of Fresno, California
The dam was constructed by the United States Army Corps of Engineers in 1954
The structural height is m (400 feet)
The dam consists of thirty-six (36) m (50 foot) and one (1) m (40 foot) wide monoliths
2019 ICOLD Benchmark Workshop - Formulation

4. 2019 ICOLD Workshop Problem Formulation
Analysis of a tallest non-overflow dam monolith 16 at Pine Flat Dam is proposed
Extensive studies was performed by UC Berkley studies in 1970’s and 1980’s
2019 ICOLD Benchmark Workshop - Formulation

5. 2019 ICOLD Workshop Physical Model The model consists of:
Single m (400 feet) high and m (50 feet) wide dam monolith
Foundation rock block m (2300 feet) long and (400 feet) deep
The geometry of the model can be provided to the participant in a Cad format
2019 ICOLD Benchmark Workshop - Formulation

6. 2019 ICOLD Workshop Case Studies Case A – Modal Analysis
Perform modal analysis of the dam-foundation-reservoir.
Case B – Simulation of Experimental Tests
Pine Flat Dam was vibrated by eccentric-mass-vibration generators (EMVG) in 1971 [2].
Workshop Contributors will be asked to perform dynamic analysis to simulate the test results.
Case C – Dam-Reservoir-Foundation Model (Foundation Properties P1)
Analysis of the model for ETAF dynamic signal with foundation properties P1 (rock).
Determine potential failure mode (PFM) and the corresponding ETAF-based failure time, and other analysis results for comparison.
Case D – Dam-Reservoir-Foundation Model (Foundation Properties P2)
Perform analysis as for Case “C” with foundation properties P2 (stiff rock).
(Which is the aim of performing the analyses with two sets of rock forundation properties?)
2019 ICOLD Benchmark Workshop - Formulation

7. 2019 ICOLD Workshop Load Case – Simulation of EMVG
Eccentric-Mass-Vibration Generator (EMVG)
Number of combination of eccentric mass and rotation speed resulted in the output exciding forces being applied at the crest of Monolith 16.
As you know, vibration tests are generally performed to characterize the modal response of structures. Which is the aim of this request? Does the structural response relevant to EMVG test be provided to participants to calibrate the model for the following analyses?
2019 ICOLD Benchmark Workshop - Formulation

8. 2019 ICOLD Workshop Load Case - ETAF
Endurance Time Acceleration Function (ETAF)
ETAF is a specially designed intensifying acceleration time history record, where the acceleration and response spectrum linearly increase with time.
ETAF acceleration (or velocity) time history is applied in upstream/ downstream direction at the base of the foundation.
ETAF will be generated for a response spectrum corresponding to the Taft Lincoln School Tunnel (Taft), Kern County, California earthquake occurred on July 21, 1952.
2019 ICOLD Benchmark Workshop - Formulation

9. 2019 ICOLD Workshop Non-linear Material
Typical material properties for concrete and rock will be provided
Density
Modulus of elasticity
Poisson ratio
Compressive strength
Tensile strength
Two sets of foundation properties will be defined P1 (rock) and P2 (stiff rock)
The non-linear materials are also related to foundation? If so, how can be managed the wave propagation in a non-elastic domain?
The typical massless approach – very often adopted according to European standards – cannot be applicable.
2019 ICOLD Benchmark Workshop - Formulation

10. 2019 ICOLD Workshop Objectives:
Estimate natural frequencies of a dam-foundation interacting with reservoir
Calibrate the FE model with the Eccentric-Mass-Vibration Generator results
Develop Potential Failure Modes for a gravity dam for two sets of foundation properties (rock and stiff-rock) (How do you define a “Failure Mode”? In terms of non-convergence of the analysis? This seems a weak criteria. In terms of excessive displacements? Others? This aspect should be better clarified.)
Compare the results of the non-linear time-history analyses for ETAF signal
Discuss accuracy of the solutions
Two further aspects could be taken into account:
Modelling of the dam-foundation interface; this is «by definition» a weak surface;
Considering that the valley has a «V» shape, a 3-D model of the dam should be considered.
2019 ICOLD Benchmark Workshop - Formulation

11. 2019 ICOLD Workshop References
USSD White Paper EVALUATION OF NUMERICAL MODELS AND INPUT PARAMETERS INTHE ANALYSIS OF CONCRETE DAMS, 2018 (draft)
Rea D., Liaw C.Y., Chopra A. K., Dynamic Properties of Pine Flat Dam, Report No. EERC 72-7, University of California at Berkeley, December 1972
2019 ICOLD Benchmark Workshop - Formulation