Foundation level for residential buildings in hilly terrain

Project description

Rwanda is one of the most densely populated countries in Africa and has recorded population growth of 2.4% per year since 2014. The average annual urbanisation rate is 6.4%. Urbanisation in Rwanda is mainly concentrated in the capital Kigali, whose population is growing by around 9% per year. Among other things, this leads to imbalances with regard to the distribution of wealth and the economic opportunities of the population throughout the country. Affordable and sustainable development concepts are therefore needed to meet the growing demand for housing and at the same time take environmental aspects into account. In this respect, the less urbanised areas, mostly in hilly terrain, as well as secondary cities in earlier stages of development offer great potential. Together with the construction company ADHI-Rwanda, HUESKER has therefore been working since 2020 to build sustainable and affordable housing in the hilly outskirts of the city of Kigali. The Bwiza Riverside Homes project is located in the middle of the mountains of Karama, Nyarugenge, west of Kigali. The centre of the capital is only 10 km away. The overall project will comprise 2,400 residential units.

Solution

The three project partners (ADHI-Rwanda, HUESKER Synthetic GmbH and Geoplast Kunststofftechnik GmbH) have developed an integrated housing solution specifically for the Bwiza Riverside Homes project, which utilises environmentally friendly, sustainable and predominantly locally available materials. The unique design of the homes is based on a patented modular system of lightweight steel frames in combination with lightweight concrete and other building materials. The hilly terrain in the project area poses a particular challenge for the construction of the houses and flats. Stepped platforms made by means of geogrid-reinforced soil (GRS construction method) therefore serve as a load-bearing foundation level for the planned development. The Fortrac® Nature system solution, a vegetated slope stabilisation system that blends harmoniously into the landscape with appropriate planting, was used. A total of 7,900 m of GRS platforms with heights ranging from 4 m to 22 m are planned. The estimated total area of Fortrac products installed at the Bwiza site over the next five years is approx. 650,000 m².

Benefits

• GRS retaining structures are extremely stable and are therefore ideal as a foundation level for the planned development.
• Faster and easier installation compared to alternative solutions.
• No specially qualified personnel or heavy equipment required.
• Harmonious integration into the natural landscape: The greenable Fortrac Nature system solution fulfils the architectural requirements of the city of Kigali.
• High flexibility in terms of design, inclination and planting.