Engineering evaluation of bearing strata at selected regions in Missan Governorate South of Iraq

Abstract EN

19 boreholes extending to 20 m depth for each were drilled in seven selected regions at Missan Governorate/ south of Iraq in order to study some geotechnical properties of their soils.

The results of standard penetration test and particle size analysis are used to classify the Quaternary deposits extending vertically to the consistency and compactness.

These layers are; stiff brown silty clay and clayey silt (CL,CH &ML), medium stiff brown and gray silty clay and clayey silt with little sand (CL,CH & ML), stiff gray silty clay and clayey silt with sand (CL &ML), very stiff gray silty clay and clayey silt (CL,CH &ML), medium dense gray silty sand (SM), hard brown clay-silt-sand mixture, silty clay and clayey silt (CL & ML) and dense and very dense gray silty sand (SM).

The bearing capacity of the first layer is suitable to hold shallow foundations of different light buildings in the study area.

For heavy structures, piles of different types must be extended to depths that vary between 14-17 m which represent the depth of 6th and 7th layers of high bearing capacity.

Plasticity chart shows that most samples are classified as inorganic clays of medium and high plasticity.

Most soils are considered to have very high degree of compressibility and high degree of expansion which must be taken in consideration at construction of shallow foundations.

The depth of groundwater in study area is shallow, varies between 1-2.5 m, which affects the strength of soil and change the capacity of bearing strata.