Mapping of Allowable Bearing Capacity for Square and Strip Footing of Al-Khalis City

Abstract

This research uses Geographic Information Systems (GIS) to assess the allowable bearing capacity of shallow foundations in AI-Khalis District, located along the Diyala River about 20 kilometres northeast of Baghdad within the Diyala Governorate.   From 12 exploration sites, each containing several boreholes, around 35 test records were gathered at different depths.   The database contained unit weights, soil classification, and results from the Standard Penetration Test (SPT).   The correlation and modification of the SPT results were used to calculate the undrained shear strength (Cu). Subsequently. Terzaghi's equations were used to determine the permissible soil bearing capacity for two types of foundations: square (B= 1.5 m) and strip (B 1 m) at excavation depths of 1 and 2 metres. The data were then collected in an Excel file and entered into the Geographic Information System (GIS) to produce maps. The results revealed a significant variation in the permissible soil bearing capacity across different depths, i.e., it gradually increases with depth. This study aims to provide geotechnical engineers with an initial view of the type of foundation and the number of layers.