Fiona Thomson
Department of Engineering
Supervisor: Colin Oram
Email: Fiona.Thomson@warwick.ac.uk
Warwick Rwenzori Hydro
Construction Challenges in Rural Projects
1.Project Overview
Over the course of the project I worked on three hydroelectric schemes in rural Uganda researching sustainable techniques to
improve electricity generation and transmission.
No matter the extent of the planning due to the sites locations and temperamental environments the schemes construction did not
always progress as scheduled. This is one example of how setbacks can be overcome.
2.Plan
3. Action
Raise the sedimentation
tanks water level
Reduce the water drop
Figure 2: Sedimentation tank wall failure
Reduced the turbulence
4. Assess the Situation
To
Increase the
efficiency of the
sedimentation tank
Figure 1: Sedimentation tank and channel.
5. Proceed
Due to the poor quality of the bricks available the
strength of the mortar far exceeds that of the
bricks therefore a larger layer of mortar was used
to increase the strength and durability of the wall.
However despite this precaution the new brickwork
was unable to bear the torque and flow of the rivers
heaviest rainfall of the year resulting in the wall
failing.
The design was flawed. At the next available
opportunity the brick walls will be replaced with
concrete to allow the sedimentation tank
optimum function.
Figure 3: Wall crack from torque is now
visible
The failure of the sedimentation tank is the most
visible issue with the site however the area is
now hazardous. The channel runs parallel with a
sheer edged mud bank, as the water passes by
the bank erosion will occur, eventually
undercutting the bank and causing a mud slide.
This site is located in a Village with many small
children. If one were to be caught in the mudslide
injury and even fatality could occur.
Figure 4: Sedimentation tank settled after
water redirected. It can function at this
point due to a less turbulent flow.
Our priority was to make the site safe as quickly as possible initiated a controlled collapse. This one action had three long
term benefits, the risk of the bank collapsing on the scheme or people was gone, the water has now been permanently
redirected removing the destructive torque from the sedimentation tank and the brick channel is now supported by mud on one
side increasing its structural integrity.
Figure 5: Water eroding
the sheer bank
Figure 6: The
controlled collapse