Classification of Bearing Strata at Nasiriya City-Thi Qar Governorate / Southern of Iraq, and Study of some of their Geotechnical Properties.

Abstract

ABSTRACTThe aim of this research is classification of the bearing strata of shallow and deep foundation of different constructions at Nasiriya City- the center of Thi-Qar Governorate/ South of Iraq. It has been detected the depths and study some of their geotechnical properties such as N-value of standard penetration test, grain size analysis, Atterberg limits, swelling potential of soil, clay activity, ground water level, organic content, gypsum content and total soluble salts. Soil investigations reports of National center of construction laboratories and researches of six locations are used in the study. These locations are distributed at a long the center on the two sides of Euphrates river. Results show that the bearing strata can be classified into four layers as follows: (1) Stiff and very stiff brown and gray clayey SILT and silty CLAY(CL&CH) (2) Medium dense gray SAND and silty SAND(SM) (3) Dense and very dense gray SAND and silty SAND(SM) (4) Hard brown CLAY – SILT – SAND mixture(CH&MH). Also, they show that the depths of bearing strata for deep foundations are between (10-13) m from surface. Liquid limits are used to estimate the potential and quantity of soil expansion. Most samples of the first layer show high potential of expansion with values between (5.93 – 19.97). The water table is located between (1.3-2.7)m . Organic content is ( 0.10 – 1.27 )% with average (0.58)%, Gypsum content is between (0.22- 1.4)% with average of (0.59)% and the total soluble salts is between (0.65 – 8.5)% with average of (2.74)% .