Abstract: Brownish-red(Quelo) sand in Angola has formed for a long time. In low moisture content, the soil has high bearing capacity; but it will reduce largely when meeting water. Ground treatment schemes often have different views. An amount of project practice and special researches prove that, there is a obvious correlation between bearing capacity and moisture content. Through sampling in pit and in-situ tests; the physico-mechanical properties of the soil are identified; through analyzing the cone penetration test (CPT) and plate loading test (PLT ) results with different moisture content, a power function relationship between bearing capacity ( fak) and moisture content for this soil is built; and a linear empirical formula between bearing capacity( fak) and cone resistance(qc) is given too. CPT results indicate that cone resistance(qc) and side friction resistance( fs) gradually increase with depth; soil is even, but friction-resistance ratio(Rf) is small. According to the analysis, it is high risk taking the non-rolled soil (original soil ) as subsoil. For multi-storey and 9-13 storey buildings, using replacement layer of compacted fill is more reasonable than pile foundation.

Key words: Angola, Quelo sand, plate loading test, static cone penetration test, moisture content, bearing capacity formula