Qhafor Ameen Hamasur

(deformation modulus of the dam / deformation modulus of the foundation rocks),
(2) they are desirable for excavation, (3) they need no or spot grouting and (4) they
have no deformability problems (except one rock mass unit), while the rock mass
units of clastic Kolosh Formation in the boreholes at the left side of Basara gorge:
(1) have some important problems that can't be neglected especially if the dam type
is Conventional Vibrated Concrete (CVC – Gravity), (2) they are less desirable for
gravity dam, (3) they need systematic grouting especially in the case of gravity dam
and (4) they have serious deformability problems especially in the case of gravity
dam construction.
Rock mass classification systems and Hoek – Brown failure criterion results
reveal that the limestone rock mass units of Sinjar Formation at the right side and of
Kolosh Formation in the boreholes at the left side of Basara gorge are characterized
by high values of RMR, DMR & GSI and better mechanical properties, but the rock
mass units of clastic Kolosh Formation at the left side and Gercus Formation at the
right side of Basara gorge are characterized by low – intermediate values of RMR,
DMR and GSI and worse mechanical properties.
This study proposes a new model which is called rock mass – valley section
model in this thesis and applied here for the three profiles (a-b, c-d & e-f profiles)
which are drawn for the first time, in which the rock mass units are projected into
each section.
Comparisons among these profiles for choosing the optimum one revealed that
the e-f profile is better than c-d profile in most aspects and c-d profile is better than
a-b profile, but the final comparison between e-f and c-d profiles revealed that the c-
d profile is more suitable than e-f profile, due to the presence of a weak sheared
zone in the right side of e-f profile which has a great negative effect on the stability of
the dam after construction and filling the reservoir and causes instability which
increases with time.
II