Investigation of effects of fracture and Lineament systems of Koh-e- Bashm hard formations in reservation and transmission of runoff waters

Koh-e- Bashm is located in north of Semnan and in Shahmirzad aera. Rozieh tunnel
with a length of approximately 3300 meters is dug below this mountain And this
tunnels is used to transfer water from the Rozieh spring to Semnan. Currently, the
output volume of water in the entrance tunnel is about 9 liters per second, and at the
mouth of the tunnel is between 40 to 50 liters per second.
The purpose of this study, investigation of effects of lithology, faults and joints in
reservation and transmission of runoff waters on Koh-e- Bashm in Semnan province.
The main formation of Koh-e- Bashm include Barut, Zagon and Lalun with Cambrian
age. Most units of this mountain have foliation to the almost vertical said. The Snow
line attitude in the project area in the months of Aban. Azar, Sfand and Farvardin are
respectively, 1746.5, 228, 717 and 2144meter and the total project area is located
under snow loss in Day and Bahman months. Bashm trust fault and several minor
faults are affected on this mountain. The Rouziea tunnels inside that dug under
Bashm mountain have two fault zones and several faults. These fault zones have
affecting role in permeability and the presences of water in Rozieh tunnel. Harvest
data for each joint, including joint slope, strike the joint, joint slope, continuity of
joint, joint space of the adjacent joints, the width of joints and and type of joint’s
Infill material. Joint continuity between 1-4 meters and the width of joints are 5 mm
and distance from each joint is 15-40 cm. The main strike of joints is Northwest-
Southeast and Northeast-Southwest. The most important factors that affected on
permeability of Koh-e- Bashm in Sedman, including lithology, faults, joints and
regional weather conditions.