Proposing a framework to combine geological and geotechnical information for city planning in Sanandaj (Iran)

Highlight
• Rock units in Sanandaj City consist of shale, limestone and andesite rock.
• Quaternary unit in Sanandaj consists of alluvial clay, residual clay and sand.
• Steps of combining geological and geotechnical data were described.
• Lacking borehole data in urban area can be resolved through geology information.
• Geotechnical zoning map of Sanandaj was extracted.

A proposed framework that combines geological and geotechnical characteristics is very useful in planning and designing construction activities in a large area, such as a city. A step-by-step process of the proposed framework is presented for the city of Sanandaj, Iran. Sanandaj was developed on Cretaceous rock units as well as Quaternary alluviums. Identifying engineering variables related to these rock units and alluvial deposits is essential for determining their behavior in construction projects. In the presented research, first, all rock types and alluvial layers in Sanandaj were determined and their properties, including their formation and origin, were described, and then, the area was geologically classified. A database including the results of 211 geotechnical boreholes at Sanandaj was compiled and data were completed and validated through the excavation of 9 pits in different locations around Sanandaj. Finally, a geological and geotechnical framework was proposed for Sanandaj to identify the city's underlying geological layers.