Dominant Direction of Structural Joints
at Majma’ah Dam Area
Saleh Al Farhood
Mohamed Al Thomiry
Majed Essa Al Motairi
Saif Al Harbi
Eng. Yahiya Al Jahmany
Civil and Environmental Engineering Department
College of Engineering, Engineering Day
23 April 2013
1
2
Objectives
This project aims to identify the strike, dip and dip
direction of a large number of joints around the dam
of Al Majma’ah Governorate. Then, to draw the "Rose
Diagram" for the resulted values in order to get the
main and dominant direction of the joints in the study
area. Results of this study will have a vital information
for the "Stress" and "Compression" structural geology
forces that affect the area of the dam which will be an
indicator for the geologic structural situation from the
land stability point of view. It will reveal the impact of
the joints on the dam body.
3
Significance to KSA
Al Majma’ah district is considered as one of
the most promising areas for sustainable
development in the Kingdom. On the other
hand, water scarcity at that region could
prevent the sustainable development at the
region. Therefore, there is a need for each
serious study that leads to better
conservation and production of this resource.
This mini project is a trial to highlight the
impact of geological structure (joints) at Al
Majma’ah dam.
4
Description of the Study Area
The area of Al Majma’ah governorate is about
(30000) Sq. km. Al Majma’ah dam lies at
the western part of the city at N 25 51.4 and
E 45 16.6
• Average elevation from MSL = 652 m.
• main width of the dam about 370 m,
• Height of the dam = 15 m.
• Capacity of storage = 5579000 m3
5
6
Field Measurements
7
Results
Results showed that the majority of the
direction of the joints within the rock layers
trend toward (NW-SE).
• Rose diagram of more than one hundred
readings showed clearly that the dominant
trend of the joints is by an angle of (120
SE).
8
Results
9
Recommendation
It is recommended that the obtained
results should be checked out to clarify
the relation with the strike, dip and dip
direction of the main structures in the
study area like folds and faults.
10
Thanks for your attentions
11