Qhafor Ameen Hamasur

Chapter One
Introduction
different rock units (Formations) on the surface and the main geological
structures in the area (folds, faults and attitudes of strata).
(3)- Investigating the topography of the area by constructing topographic profile at
various sites to find the optimum profile for dam site selection.
(4)-Integrating all the various geotechnical, geological and topographic (slope)
data and preparing rock mass – valley section models (for the first time) for
different sites and comparing them to find the most suitable site for dam
construction.
1-5 Research methods
1-5-1 Field work
The field work started in Feb.-2007 and extended to March-2008 for the
period of 160 days (104 days for general survey of the study area and detailed
study at and near the proposed dam site, 54 days for drilling three boreholes in
the left side of the proposed dam site).
As there is no precise geological map about the area, a detailed geological
survey of the area was conducted, using a topographic maps with a scale of
1:20000 (Maps No. 71/670 and 71/680 after the directorate general of surveys,
Baghdad – Iraq) as a base map for preparing a geological map of the area.
The geological survey included a description of the existing formations,
measuring the dip and strike of all contacts between formations at numerous
locations in the area. The altitude, latitudes, longitudes of the mentioned locations
and along the axes of anticlines and synclines were recorded using GPSMAP
60CSx. Finally, the obtained data were projected on the topographic map to draw
the geological map of the area.
Detailed information at the proposed dam site was collected for rock mass
evaluation. To achieve this task, three surface stratigraphic sections and three
boreholes were selected, Fig (1-2).
Each section or borehole was divided into a number of rock mass units
depending on the lithological (change in rock type) and structural properties (such
5