RN7, section Dosso-Bella II (83 km) and Dosso – Bella II – Gaya (157 km) road

Control and supervision of rehabilitation works of RN7, section Dosso-Bella II (83 km) and Output and performance-based road contracts (OPRC) of the Dosso - Bella II - Gaya (157 km) road

Country

Niger

Name of Client

Dosso region

Duration

11/2020 - 07/2025

Project Description

The project provides for the full-width recycling of the existing road, the implementation of a foundation layer of lateritic gravelly cement stabilized with cement, the implementation of the base layer of 10 cm gravel bitumen and an asphalt concrete wearing course of 5 cm. The works also include localized soil replacement, the upgrading UEMOA of the road (10.2 including 7.2 m of roadway and 2 X 1.5 shoulders), the construction of 44 culverts of different sizes, gutters and hydraulic protections.

The ESIA component is highly developed with the implementation of mitigation measures, awareness-raising and support measures.

Following the rehabilitation works, maintenance of the road is planned with the GENiS (or MROR) method.

Road project geometry:

  • Total road length: 88 km
  • Width of the road in open countryside: 2 m
  • Width of the road in built-up areas: 2 m

Road quantities:

  • Earthworks (fill/cut): 90 000 m3
  • Cement stabilized foundation layer: 190 000 m3
  • Base layer in GB: 104 000 m3
  • Wearing course BB: 35 000 m3

Structures:

  • Box culverts: 5 000 m
  • Pipe culverts:         44

Services Description

  • Initial critical review of the design (plan, calculation notes, specifications, etc.) of the Dosso-Bella II road
  • Technical control of all the works required to guarantee the required quality in accordance with the standards in force
  • Control of services relating to environmental and social measures, in accordance with environmental and social clauses included in the Company's contract, in terms of quality, cost and time
  • Supervision of the various control tests necessary for the implementation of the works
  • Administrative and financial control essential for the smooth running of the work
  • Acceptance of the works at the end of the rehabilitation of the Dosso-Bella II section of 83 km
  • Technical inspection linked to the rehabilitation phase of the 83 km Dosso-Bella II section