Technical Issue:
The school building is experiencing differential settlement due to the aging of the structure and weak soil conditions beneath the foundations. This is primarily caused by the building being in operation for over fifty years, which has led to a deterioration in the bearing capacity of the supporting soil.
Required Solution:
To stabilize and improve the soil beneath the existing foundations without altering the structural system, with the objective of:
- Stopping the current differential settlement,
- Preventing future settlement, and
- Extending the service life of the building while ensuring its structural safety going forward.
The following works have been carried out at the school site:
1. Structural Analysis:
- A comprehensive structural analysis was conducted to identify the foundations subjected to high stress.
2. Soil Testing:
- Soil investigation (boreholes) was carried out at various locations across the school to determine the actual bearing capacity of the soil.
- The groundwater level was also accurately identified within the scope of the analysis.
3. Identification of Unsafe Foundations:
- Based on the structural analysis and soil test results, the foundations requiring strengthening and remediation were identified.
4. Soil Stabilization:
- Soil injection was performed using Polyurethane Foam, a pressure-injected material that enhances the soil’s bearing capacity.
- The injection pressure ranged from 100 bar to 150 bar, as per site monitoring and the manufacturer’s recommendations.