Introduction

This assignment is worth 10%. It must be done by students without collaboration with each other. It is due no later than :HGQHVGD 4 WK October 2023, pm, and is to be uploaded through Moodle. The VXEPLVVLRQ LV WR EH QR ORQJHU WKDQ SDJHV, showing the calculations performed, assumptions made, the software output and computed bearing capacities. It may contain handwritten sections or be typed.

Assignment

Consider storage tanks proposed for a desalination plant to be supported by surface strip footings on sand. During a geotechnical site investigation the groundwater level was measured to be 4 m below the ground surface. The suctions were measured to be 25 kPa, 15 kPa and 10 kPa at the ground surface, 1.0 m and 2.0 m depths, respectively. The soil was known to have undergone drying in the weeks prior to the site investigation so the hydraulic state is assumed to be located on the main drying curve.

Using SigmaW, PLAXIS or some other software, as well as a bearing capacity equation, compute the bearing capacities of 2.5 m wide smooth and rough strip footing for the cases:

(i) when the measured soil suctions are considered,

(ii) when the soil is assumed dry, and

(iii) when the water table is assumed to be at ground level.