Geotechnical interpretive report from borehole logs, with bearing capacity and settlement

Northbank Developments wants to build a five-storey mixed-use building on a 45 x 30 m plot of a former rail yard. The ground floor will be retail and the upper floors apartments. The structural engineer expects column loads of about 1,800 kN at interior columns and 1,100 kN at edge columns, on a 7.5 m grid.

A site investigation contractor has drilled six boreholes to 15 m and run standard penetration tests every 1.5 m. Their factual report is a stack of logs and lab sheets. Nobody has interpreted them yet. The developer wants to know, within four weeks, whether pad footings will work or whether the building needs piles, because piling would add around 8% to the budget.

You will write the geotechnical interpretive report. The ground broadly consists of: - 1.0 to 2.0 m of made ground with ballast and ash; - soft to firm clay to between 4.5 and 6.0 m, with undrained shear strength of roughly 35 to 65 kPa; - medium dense to dense sand to about 12 m, with SPT N rising from about 12 to 35; - very dense gravel below 12 m.

Groundwater was found at 2.2 to 2.8 m. In task 1 you will create the six logs and lab results consistently with this description, so that your data is realistic and stated as synthetic.

You will build a ground model and cross-sections, derive characteristic parameters, check pad footings for bearing capacity and settlement, assess a piled option, and recommend a foundation type with its risks.

Done means the developer can make the pad-or-pile decision from your summary page, and the structural engineer can design from your parameter table.