عنوان مقاله [English]
Assessment and investigation of soil and bedrock properties is of an essence for construction of residential, commercial as well as industrial complexes. In order for the foundation system of such projects to be opted, it is necessary to assess the geotechnical characteristics of the site. In many projects where the site is located on problematic soils or non-engineered fills, if the accumulation of the soil is done with no specific consideration of controlling the fill thickness and compaction, the soil will experience some major problems regarding volumetric changes, bearing deficiencies, and internal instability. Therefore, it is crucial in such fills to employ some soil improvement and preservation measures in accordance with their materials, time and circumstance of the fill formation. In construction procedure of a complex near Tehran, due to non-engineered accumulation of debris and inappropriate compaction, it was recognized that the project was prone to unallowable differential settlement and instability, and for this reason, it was required to improve the subsoil properties by means of ground improvement techniques. Moreover, owing to the significant depth of problematic soils, the shallow improvement approaches would not suffice, and consequently, using semi-deep or deep improvement techniques were mandatory. In this paper, the geological characteristics of the site in line with assessment of the soil geotechnical properties after improvement were analyses in order to select the more appropriate improvement methods. Among different alternatives, the combination of earth works, shallow compaction, jet grouting and employing micropiles was shown to be the more optimum option from economical, technical, and feasibility perspectives, and therefore, was employed in the project.