The study presented by the student aims to improve the collapse of gypsum soils using a laboratory model that is similar to reality. In addition, numerical modeling, using PLAXIS-3D software, was performed to evaluate the collapse behavior and provide a comparison with laboratory results.

The defense committee consisted of:

-  Prof. Dr. Mahdi Obaid Karkush, Chairman

- Assist. Prof. Dr. Khaled Rasim Mahmoud, member

- Assist. Prof. Dr.  Moayad Abdul-Jabbar Ahmed, member

- Prof. Dr.  Ahmed Hazem Abdel Karim, member and supervisor

- Assist. Prof. Dr. Nabeel Shaker Mahmoud, member and supervisor

The thesis included conducting a gypsum soil compaction test, by compacting the upper layer of test samples (thickness from 50 to 100 mm) under the foundation to the maximum dry density, as obtained from the standard compaction test. Water treatment sludge, cement kiln dust (CKD), and geogrids were also used. Cement kiln dust or sludge was also combined with reinforcing grids to improve the compacted upper layer

The model results indicated that the collapse susceptibility reduction factor (CSRF) was (75%) when the top layer was compacted with a thickness of (50 mm) to the maximum dry density. When the sludge was used with the upper layer, the CSRF value was (86.2%). The CSRF values for the CKD-treated and meshed soils were (82% and 88.6%), respectively. These values increased up to (94% and 94.6%) when applying a mixture of sludge or CKD with the clamps. As discussed in this study, the above treatment methods can be effectively used to improve the collapsibility of gypsum soil. In addition, numerical modeling, using PLAXIS-3D software, was performed to evaluate the collapse behavior and provide a comparison with laboratory results. There was good agreement between the results obtained from the numerical model and those obtained from the laboratory model, as the variance between them was within ±20%.

The defense was attended by the Dean of the College, Prof. Dr. Ameer Abdel Rahman Hilal, the respected and Assistant Dean for Scientific Affairs and Higher Studies, Assist. Prof. Dr. Mohamed Abdel Ahmed, and Assistant Dean for Administrative Affairs, Dr. Ahmed Anis, the respected Head of the Civil Engineering Department, Assist. Prof. Dr.  Ahmed Tariq Noman, and a number of studies students in the department.

Congratulations to the student for obtaining his degree, and to the defense committee and success. We wish him to pursue his scientific studies

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