الفهرس 
Objectives and MethodologyOnly 14 pages are availabe for public view
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Abstract
This study sheds the light on a one of the soft clay soil stabilization techniques that can stabilized the shear strength of soft clay soil this technique is known as lime columns stabilization technique. Lime columns can form in-situ by using the deep mixing tools. It also can be pure lime columns or columns consists of lime with any other materials which helps in increase the column strength and increase the stabilization rate of surrounding soil such as lime-cement and lime-soil columns. This technique is considered one of the deep stabilization techniques in which the columns are installed to stabilized deep soft clay soil layers. Also, it can be used to stabilize road embankments, different types of fills and natural slopes. Moreover, lime columns stabilization technique can be used to reduce settlements for embankments and light structures. The influence of the lime columns on improving the soil strength is depend on the types of soil. The lime column technique is used to stabilize the shear strength behavior of soft clay soil with a good technical and economical result.In this thesis a detailed experimental study consists of (7) series which contain (47) tests is performed to investigate the effect of lime columns stabilization technique on the shear strength behavior of soft clay. A series of large direct shear box test is carried out using different parameters such as column diameter, area ratio, loading direction and curing time. The effect of the spacing between columns and the column material is also investigated. Test results indicate that, the shear strength of soft clay soil is increased with using the lime columns stabilization technique. The shear strength increased gradually with increasing the diameter/length (D/L) ratio of the single column. It increased by a small ratio equals 17% when using a lime column with (D/L) equals 0.13 compared to unstabilized soil. While, with increasing the (D/L) ratio to 0.18 the shear strength increased by 30%. The maximum increasing in shear strength is found at (D/L) ratio equals 0.28 it increased by 63% compared to unstabilized soil. Otherwise, from large direct shear box test results, it is found that the shear strength of soft clay soil is increased with increasing number of columns, it increased with an obvious rate when the columns number increased from 1 to 2, 3 and 4 columns with increasing ratio reached to 53%, 123%, 180% and 250% respectively at (D/L) ratio equals 0.28 compared to unstabilized soil. While, with increasing the number of columns to 5 and 6 lime columns the maximum increasing ratio is noticed, it reached to 300% and 327% respectively at (D/L) ratio equals 0.28 compared to the case of unstabilized soil.