The instability of slopes and retaining structures alongside hill and mountain roads in high rainfall, tropical and sub-tropical regions creates considerable annual problem for road managers and maintenance engineers. During each wet season, failures occur and roads are blocked or sometimes completely severed. This can cause significant disruption to traffic and pose a safety hazard. High annual maintenance costs are incurred to keep the roads open.
In this environment, natural instability is common. Road construction or widening can exacerbate existing stability problems and, through excavation, spoil disposal and poor drainage arrangements, can create significant additional instability. Under these circumstances, and in view of the limited resources available for rural road networks, it would be totally impractical and, in reality, impossible to attempt to stabilise all the areas of instability affecting the road network.
Fortunately there are low-cost mitigation methods that can provide preventive and repair solutions at reasonable cost. Some of these methods use natural vegetation and labour-based techniques, with associated local employment and environmental benefits; reducing the 'carbon footprint' compared to using traditional reinforced concrete and cement based structures.
The documents downloadable from this web page provide examples of recent experience in Low Cost Slope Stabilisation.
Contributions from Messrs Gareth Hearn, John Howell and Tim Hunt.
For further details please refer to the SEACAP 21 project webpage.
If you would like to make a contribution to this topic or help to 'sign-post' any key documents on the topic for gTKP partners and users, please contact info(at)irfnet.ch
Updated December 2009