Geotechnical correlations are widely used because it can provide fast and cost-effective means of parameter estimation using simple tests. Most of the current correlations were derived from data fitting of measurements for specific site conditions and need to be evaluated before used in other sites. During the correlation development, the deviation of the correlation from the measured values was evaluated using simple statistical measures. A better method of correlation evaluation may reduce the overall deviation of the geotechnical parameter. Amended Theil Inequality Coefficient (ATIC) is proposed as an evaluation tool because it has the advantage that it considers both position and trend conformities between observed and correlated values. To address the efficiency and rationality of ATIC, evaluation of, 92 compression index correlations by ATIC and different statistical measures was carried out. Comparison between the results showed that ATIC is efficient in assessing the best and worst correlations and it can be considered a good tool for correlations evaluation.

Diaphragm walls (slurry trenches) is more needed nowadays in urban areas and crowded cities where underground constructions as subways, deep basements and utilities as pump stations, underground tanks and tunnels mainly depending on drilling methodology using slurry trenches. Many researchers and different codes of buildings have discussed the risk issues related to design analysis or materials but hardly find scientific researches discussing quality control on site during construction process and its effect on the overall quality of the work needed. Some of these issues is geometrical imperfections such as the positioning error of drilling rigs during trenching, small seepage passages through the diaphragm wall may occasionally occur, which will undermine its water-tightness and lead to significant leakages. This study focus on examination of penetration of seepage passages and it further quantitatively estimates the flow rate through the diaphragm wall under certain circumstances.

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Soft clay is a problematic soil due to its low bearing capacity and high settlement. To treat such soil, many techniques were developed, such as a replacement method with sand bed, stone columns, sand columns, vertical sand drains…. etc. The main objective of this study is to investigate the effect of the introduction of slag-cement dust columns to soft clay on the consolidation parameters such as coefficient of consolidation, compression index, and compressibility index. Three consolidation tests were carried out on three soft clay samples. The first sample was soft clay without treatment. The second sample was soft clay treated with one slag-cement dust column, and the third sample was treated with three slag-cement dust columns. All Samples were tested in a Modified Consolidation Apparatus. A relationship between void ratio and stress was deduced.The tests showed that the columns increased the clay consolidation rate and decreased the compression index, where the columns absorbed the clay water content. The consolidation coefficient values for the treated clay soil proved that Han's model applies to clay treated with slag-cement dust columns (SCCs).