The College of Engineering at the University of Baghdad hosted the public defense of Master’s student Aqeel Jaafar Sadah from the Department of Civil Engineering for his thesis entitled:
“Enhancement of the Uplift Resistance of Shallow Footing Using Inclined Structural Skirts.”
The discussion took place on Thursday, September 25, 2025, in Prof. Dr. Khalid Shakir’s Hall at the Department of Civil Engineering, under the supervision of Prof. Dr. A’amal A. H. Al-Saidi.
The study focused on the behavior of shallow skirted foundations under uplift forces placed on loose sandy soil with a relative density of 30%. A total of 182 laboratory tests were conducted on square footings with and without skirts and piles. The tests were divided into two categories with displacement rates of 0.5 mm/min and 2 mm/min, each including two skirt types (chamfered and straight corners) and various modifications such as surface roughness enhancement and anchoring using expanded metal lath and wings. Two pile types (open-ended and closed-ended) were also tested.
The research examined multiple parameters:
- Embedment ratios of (0.5, 1, 1.5, and 2)B, where B is the footing width.
- Inclination angles of (0°, 15°, 30°, and 45°).
- Roughened inner skirt surfaces using expanded rib lath mesh.
- Wings attached at the lower edge of the skirt.
- Pile embedment ratios of (5, 10, and 15)D, where D is the pile diameter.
Key findings included:
- The use of skirts significantly increased the uplift capacity of shallow footings.
- The highest uplift resistance was achieved at an embedment ratio of 2B, an inclination angle of 45°, and the addition of wings for both skirt types.
- For a displacement rate of 0.5 mm/min, the straight-corner skirt achieved an uplift capacity of 525 N (an improvement of 37.86 times) compared to the chamfered-corner skirt with 376 N (an improvement of 27 times) and the unskirted footing with 13.88 N.
- At 2 mm/min, the straight-corner skirt achieved 534 N (an improvement of 44.37 times), compared to 407 N (33.82 times) for chamfered corners and 12.05 N for the unskirted footing.
- The inclination angle had a greater influence on uplift capacity than the skirt length.
- The skirted footing proved to be a promising and cost-effective alternative to uplift piles. The maximum uplift capacity for closed-end piles (56.25 N at 0.5 mm/min) was 1.42 times lower than that of skirted footing with a 2B embedment ratio and 0° inclination, and 9.33 times lower than that of the 2B embedment ratio, 45° inclination, straight-corner skirt. Similar behavior was observed at 2 mm/min.
Following a comprehensive scientific discussion and evaluation by the examination committee, Aqeel Jaafar Sadah was awarded a Master’s degree in Civil Engineering / Soil Mechanics and Foundation Engineering with distinction.
