19/06/2020
GEOTECHNICAL INVESTIGATIONS – ‘Collapsible Soils'
It is well known that soil behavior is dependent on its effective stress. Soils that have the potential to collapse, at their natural state, possess high apparent strength but are susceptible to huge reduction/lessening on wetting, additional load, or both. Therefore, collapsible soils are considered problematic soils & can lead to major engineering problems to infrastructures if not taken into consideration.
These soils are normally found in our region, semi-arid to arid, in such soil deposits as aeolian, alluvial, fine/coarse colluvium, transported, loessial, residual or from manmade fills.
Collapsible soils are typically characterized by loose structures (eg pinholes), low dry density, low plasticity & low moisture content. However, on wetting they suffer large deformation, rapid settlement & high decrease in loose structures, ie collapse, which could be severe in some cases!
Soil collapse has historically caused severe damages to dams, pipelines, fields, roads, buildings, etc.
A geotechnical investigation would establish the soil’s collapse potential by collecting either undisturbed double oedometer, collapse potential or consolidation samples for lab testing. The role of the geotechnical investigation is to identify, sample, test, analyze results, draw conclusions & recommend mitigation &/or stabilization measures.
To mitigate against this potential hazard either the home needs to have a special foundation built, or the problem soils must be over-excavated and suitable soils placed and compacted very carefully during the building process—with very special care taken in assuring the water content and fill layers are exactly per an engineer’s specifications.
To help you conduct a thorough geotechnical investigation, contact Geo-Front Group;
(+267) 398 1992/72 107 120/74 33 2929
[email protected]
