Construction of the Memve'ele hydroelectric dam on the Ntem

Under its Energy Sector Development Plan, the government of Cameroon has embarked upon a vast programme of developments to make up for the country's electricity production shortfall.

An Assistance to Contracting Authority (AMO) mission was entrusted, in October 2014, to the national Civil Engineering Laboratory (LABOGENIE) which then entrusted FONDASOL with a geotechnical mission to assess the design of the structures.

The development will include in particular:

• A main dam 1.8 km long, with a maximum height of 15 m with 2 types of section (rockfill with a clay core/homogeneous earth)
• An inlet channel approximately 3.2 km long
• A secondary dam 0.6 km long, with a maximum height of 17 m, rockfill with a clay core
• Permanent embankments next to the production plant with a maximum height of about 70 m
• Permanent roads 1 access route to the plant 8.7 km long, 2 service roads, 3.4 and 5.5 km long

Geotechnical assessment of the design of the dam

For this study, FONDASOL analysed the technical choices made and checked the key points in the design of the geotechnical structures.

In addition it submitted an evaluation report on the geotechnical design including:

• Synthesis and analysis of the design criteria for the final earthworks
• Verification of the key points of this design (resistance to slippage, settlement of the dams, leakage rate and internal erosion)
• Analysis of the auscultation systems for the earth structures
• Analysis of the road structures planned for the permanent roads

Methodology

• Critical analysis of the methods of justification of the structures chosen
• Critical analysis of the geotechnical hypotheses used for the calculations
• Verification counter-calculations using different software
• Parametric studies on certain geotechnical hypotheses to assess the robustness of the design
•  pour juger de la robustesse du design