The College of Engineering at the University of Baghdad hosted the public defense of Master’s student Rawaa Rafea Khudair from the Department of Civil Engineering for her thesis entitled:
“Experimental and Mathematical Evaluation of Loosely Skirted Foundation Compared to Circular Foundation on Reinforced Sand.”
The discussion took place on Thursday, October 2, 2025, in Prof. Dr. Khalid Shakir’s Hall at the Department of Civil Engineering, under the supervision of Prof. Dr. Bushra Suhale Albusoda.
The study aimed to examine the behavior of loosely skirted circular footings on loose sandy soil under various loading conditions, including eccentricity and inclination, as the skirt diameter (Ds) and skirt length (Ls) increased. It also investigated the effects of geogrid reinforcement on bearing capacity and settlement performance. A comparative analysis was conducted between circular footings and loosely skirted circular footings under different loading and soil conditions (reinforced and unreinforced).
A total of 116 small-scale physical models were constructed in three groups: shallow foundations, skirted foundations, and foundations on loose sandy soil (Dr = 30%) reinforced with geogrid layers. The foundations were subjected to vertical, eccentric, and inclined loads, and the influence of skirt dimensions and reinforcement spacing (h = 0.2D, 0.4D, and 0.6D) was evaluated.
The research produced several significant findings:
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The improvement factor (IF) increased by 1.60–2.71 for skirted foundations and 2.13–3.57 for reinforced soil under eccentric and inclined loads.
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The settlement reduction factor (SRF) decreased by 45–70% with skirted foundations and 58–79% with reinforced soil.
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The optimal reinforcement spacing (h) was found to be 0.4D, while the ideal skirt configuration occurred at Ds/D = 1.4 and Ls/D = 1.5.
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The maximum improvement in load-bearing capacity reached 54% with reinforced soil and 36% with loosely skirted foundations.
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However, the reinforced soil technique showed higher sensitivity to eccentric and inclined loading conditions.
Following the scientific deliberations of the examination committee and the researcher’s successful defense, Rawaa Rafea Khudair was awarded a Master’s degree in Civil Engineering / Soil Mechanics and Foundation Engineering with distinction.
