Vertical and Inclined Lime Injected Piles Under Footing Resting on Collapsing Soil

• Published in: Journal of the Institution of Engineers (India). Series A, Civil, architectural, environmental and agricultural Engineering Vol. 101; no. 3; pp. 513 - 521
• Main Authors: Zakaria, Waad A., Abbas, Hassan O., Aljanabi, Qasim A.
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 01.09.2020; Springer Nature B.V
• Subjects: Civil Engineering; Collapsible soils; Engineering; Gypsum; Inclination angle; Original Contribution; Soil conditions; Soil improvement; Soil lime; Gypseous soil; Improvement; Lime piles; Collapsing soil; Collapse potential
• ISSN: 2250-2149; 2250-2157
• DOI: 10.1007/s40030-020-00449-1

Gypseous soil, as one type of collapsible soils, is widely separated in Iraq. Gypsum concentrations of more 60% are not uncommon, and such soils are present in the western and northern parts of this country. Distresses in engineering facilities resulting from high collapse settlements are well known by the locals and as such causing much financial problems in government and private sectors. Soil improvement and replacement techniques are used as a result of tackle the large collapse of the soil. This laboratory research is directed in using lime piles to reduce the collapse potential of the gypseous soil. A comparison study is conducted between vertical lime piles and inclined lime piles. The inclination angle is chosen arbitrarily to be 30° to the vertical. A plain strain footing is used to simulate the separate foundation having length-to-width ratio ( L / B ) of 4. Three spacing patterns are used for each case of lime piles, namely B /3, B /2 and B . Test results reveal that inclined lime piles have much advantage over the vertical ones in reducing the collapse potential. Measured improvements in reducing settlement for inclined over vertical lime piles are 42% for spacing of B /3, 46% for spacing of B /2 and 27% for B . Unfortunately, the presence of lime piles has been found experimentally to increase the settlement in case, the collapsing soil is in dry condition compared to the untreated soil.