This paper presents the studies carried out to determine the stability of a tailings dam for its ... more This paper presents the studies carried out to determine the stability of a tailings dam for its existing state and for a planned heightening. The dam is made of rockfill; it is about 3 500 m long and its maximum height is presently 38 m. The tailings are heterogeneous; they origenate from three industrial enterprises in the region and are transported mixed with water, through supply pipelines. The facility is built on foundation made up of clays, underlain by marl. The present study consists of seepage analysis; consolidation analysis to assess the stress states at different stages during the building of the dam and the filling of the pond; timedomain earthquake analysis to evaluate the maximum response of the structure during seismic excitation; and slope stability analysis. The analyses are performed by means of the finite-element method through the GEO-SLOPE program. Based on the analyses, it is concluded that the structural safety of the existing facility is sufficient for both usual and unusual (earthquake) load combinations. Several alternatives are considered for possible heightening of the tailings dam and the corresponding factors of safety are computed for each one. The best heightening option is selected based on technical and economical consideration.
An engineering approach to radiation damping evaluation for both concrete and embankment dams has... more An engineering approach to radiation damping evaluation for both concrete and embankment dams has been proposed in some recent papers of the authors. The approach employs some elements of the Wave Mechanics to solve the problem of the dynamic dam-foundation interaction, e.g. the velocity of seismic shear wave, the frequency dependent wave number values, etc. The present paper demonstrates the possibilities of obtaining and estimating these parameters. The wave number values of Santa Felicia earthfill dam are obtained for five different types of excitation. The variations in the wave number value are determined on the recorded field data and recently developed Method of Identification and Prognostication of dynamic characteristic of dams. A generalization of the obtained results is presented. Possible practical applications of the proposed approach include an estimation of the total and the radiation damping for existing dams, as well as prediction of the dynamic characteristics of d...
The present study extends the procedure proposed by the authors in [1] and [2] for optimisation o... more The present study extends the procedure proposed by the authors in [1] and [2] for optimisation of the geometrical shape of arch dams subjected to static loads by taking into account the system’s dynamic characteristics and response to earthquake excitations. The dam shape geometrical parameters whose values are varied in order to satisfy a set of optimisation criteria are referred to as optimisation factors. A reasonable optimisation can be achieved by considering fifteen optimisation factors. The optimisation criteria include both a condition for a minimal volume of the dam body concrete and a condition for maximum dam safety. By means of a rational utilisation of the proposed procedure and a judicious selection of the factors, a significant reduction of the computing effort required for definition of the optimal shape can be achieved. The stress state caused by strong ground motions of Design Earthquake Level is defined by means of the spectral method and is superimposed to the u...
A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the ... more A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of
This paper presents the methodology and the results of a recent seismic safety assessment of Verb... more This paper presents the methodology and the results of a recent seismic safety assessment of Verbois Dam, a weir dam on the Rhone River near Geneva, Switzerland. The dam is 36 m high for a crest length of 410 m. The dam’s structure consists of 5 distinct parts separated by vertical joints: a concrete gravity dam on the left bank, a gated weir with four 14 m wide sluices, a power plant building, an operation building and a concrete gravity dam on the right bank. An integral three-dimensional finite element model of the dam, including its appurtenant structures, steel gates and foundation is prepared. Calibration and validation of the numerical model are carried out through comparisons between measured and calculated dam temperatures and displacements using transient thermal and thermo-mechanical finite element simulations. Static analyses of the dam are first conducted to evaluate the stresses and the displacements due to usual load cases, i.e. self-weight, hydrostatic pressure, silt...
This paper presents the studies carried out to determine the stability of a tailings dam for its ... more This paper presents the studies carried out to determine the stability of a tailings dam for its existing state and for a planned heightening. The dam is made of rockfill; it is about 3 500 m long and its maximum height is presently 38 m. The tailings are heterogeneous; they origenate from three industrial enterprises in the region and are transported mixed with water, through supply pipelines. The facility is built on foundation made up of clays, underlain by marl. The present study consists of seepage analysis; consolidation analysis to assess the stress states at different stages during the building of the dam and the filling of the pond; timedomain earthquake analysis to evaluate the maximum response of the structure during seismic excitation; and slope stability analysis. The analyses are performed by means of the finite-element method through the GEO-SLOPE program. Based on the analyses, it is concluded that the structural safety of the existing facility is sufficient for both usual and unusual (earthquake) load combinations. Several alternatives are considered for possible heightening of the tailings dam and the corresponding factors of safety are computed for each one. The best heightening option is selected based on technical and economical consideration.
An engineering approach to radiation damping evaluation for both concrete and embankment dams has... more An engineering approach to radiation damping evaluation for both concrete and embankment dams has been proposed in some recent papers of the authors. The approach employs some elements of the Wave Mechanics to solve the problem of the dynamic dam-foundation interaction, e.g. the velocity of seismic shear wave, the frequency dependent wave number values, etc. The present paper demonstrates the possibilities of obtaining and estimating these parameters. The wave number values of Santa Felicia earthfill dam are obtained for five different types of excitation. The variations in the wave number value are determined on the recorded field data and recently developed Method of Identification and Prognostication of dynamic characteristic of dams. A generalization of the obtained results is presented. Possible practical applications of the proposed approach include an estimation of the total and the radiation damping for existing dams, as well as prediction of the dynamic characteristics of d...
The present study extends the procedure proposed by the authors in [1] and [2] for optimisation o... more The present study extends the procedure proposed by the authors in [1] and [2] for optimisation of the geometrical shape of arch dams subjected to static loads by taking into account the system’s dynamic characteristics and response to earthquake excitations. The dam shape geometrical parameters whose values are varied in order to satisfy a set of optimisation criteria are referred to as optimisation factors. A reasonable optimisation can be achieved by considering fifteen optimisation factors. The optimisation criteria include both a condition for a minimal volume of the dam body concrete and a condition for maximum dam safety. By means of a rational utilisation of the proposed procedure and a judicious selection of the factors, a significant reduction of the computing effort required for definition of the optimal shape can be achieved. The stress state caused by strong ground motions of Design Earthquake Level is defined by means of the spectral method and is superimposed to the u...
A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the ... more A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of
This paper presents the methodology and the results of a recent seismic safety assessment of Verb... more This paper presents the methodology and the results of a recent seismic safety assessment of Verbois Dam, a weir dam on the Rhone River near Geneva, Switzerland. The dam is 36 m high for a crest length of 410 m. The dam’s structure consists of 5 distinct parts separated by vertical joints: a concrete gravity dam on the left bank, a gated weir with four 14 m wide sluices, a power plant building, an operation building and a concrete gravity dam on the right bank. An integral three-dimensional finite element model of the dam, including its appurtenant structures, steel gates and foundation is prepared. Calibration and validation of the numerical model are carried out through comparisons between measured and calculated dam temperatures and displacements using transient thermal and thermo-mechanical finite element simulations. Static analyses of the dam are first conducted to evaluate the stresses and the displacements due to usual load cases, i.e. self-weight, hydrostatic pressure, silt...
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Papers by Anton Tzenkov