24-09-2014, 11:02 AM
Elastic and Elasto-Plastic Analysis of Gravity Dam-Foundation System
without and with Shear Seams
[attachment=68426]
ABSTRACT
India is endowed with rich hydro-power potential but till date, only about 23% of the
country’s vast hydro-power potential has been harnessed. Dams form a major component
of a hydro-power project and apply significant loads to the underlying geologic media
and disturbs the pre-existing natural conditions. The interaction of the dam with the
foundation, especially one with difficult or troublesome geology, needs systematic study.
The literature is lacking detailed studies on the influence of foundation modulus,
inclinations of the set of joints present in the dam foundation on the stress-deformation
response of dam-foundation system. Systematic studies to define the effective depth of
concrete plug to be provided for the treatment of dam foundation with shear seam are
also not available except for the practical studies carried out at Shasta and Bhakra dam
projects.
In the present work parametric studies are carried out using the Universal Distinct
Element Code (UDEC) for:
Dam-foundation interaction for the foundation idealized as a continuum rock mass
with different equivalent rock mass modulus values. • Dam-foundation interaction for the foundation idealized as jointed rock mass with
different equivalent rock mass modulus values and various inclinations of single set
of joints and orthogonal set of joints.
• Dam-foundation interaction for foundation idealized as a continuum rock foundation
with shear seam of varying inclination.
The dam-foundation system is analyzed for two loading conditions viz. (i) Loading
condition ‘A’ i.e. construction of dam completed but no water in reservoir or tail water
and (ii) Loading condition ‘B’ i.e. full reservoir level, with extreme uplift, assuming the
drainage holes to be inoperative. Plug efficiency curves are developed for different
depths of concrete plug for loading conditions ‘A’ and ‘B’. Equations are also proposed
to calculate the depth of concrete plug to be provided as dental treatment for shear seams
in terms of dam height, seam width and foundation modulus.
without and with Shear Seams
[attachment=68426]
ABSTRACT
India is endowed with rich hydro-power potential but till date, only about 23% of the
country’s vast hydro-power potential has been harnessed. Dams form a major component
of a hydro-power project and apply significant loads to the underlying geologic media
and disturbs the pre-existing natural conditions. The interaction of the dam with the
foundation, especially one with difficult or troublesome geology, needs systematic study.
The literature is lacking detailed studies on the influence of foundation modulus,
inclinations of the set of joints present in the dam foundation on the stress-deformation
response of dam-foundation system. Systematic studies to define the effective depth of
concrete plug to be provided for the treatment of dam foundation with shear seam are
also not available except for the practical studies carried out at Shasta and Bhakra dam
projects.
In the present work parametric studies are carried out using the Universal Distinct
Element Code (UDEC) for:
Dam-foundation interaction for the foundation idealized as a continuum rock mass
with different equivalent rock mass modulus values. • Dam-foundation interaction for the foundation idealized as jointed rock mass with
different equivalent rock mass modulus values and various inclinations of single set
of joints and orthogonal set of joints.
• Dam-foundation interaction for foundation idealized as a continuum rock foundation
with shear seam of varying inclination.
The dam-foundation system is analyzed for two loading conditions viz. (i) Loading
condition ‘A’ i.e. construction of dam completed but no water in reservoir or tail water
and (ii) Loading condition ‘B’ i.e. full reservoir level, with extreme uplift, assuming the
drainage holes to be inoperative. Plug efficiency curves are developed for different
depths of concrete plug for loading conditions ‘A’ and ‘B’. Equations are also proposed
to calculate the depth of concrete plug to be provided as dental treatment for shear seams
in terms of dam height, seam width and foundation modulus.