Work performed
- Silo stabilization
- Installation of monitoring devices (tiltmeters, H-level and electronic crack meters)
- Silo cleaning
- Erection of a 25 m scaffolding tower inside the silo
- Installation of reinforcement steel
- Shotcrete
- Silo roof reinforcement
Scope
A cement manufacturer required an inspection and recommendations for its cement silos after evident cracking appeared on the silo shells. The inspection showed the extent of deterioration: to ensure safety and extend the design life, the structures had to be stabilized to avoid imminent collapse, and then reinforced.
Access
A man-basket was used for the first stage of the project — silo stabilization — which comprised the installation of 12 metal straps around the silos. The man-basket also gave access to all six silos from every angle during the installation of the tiltmeters and crack meters.
During silo cleaning, TALOS rope access technicians used the roof manhole to reach the soffit and interior walls. Once cleaning was complete, the side doors were used for steel fixing and shotcrete.
Solution
TALOS first carried out an extensive inspection of the six silos, including non-destructive and semi-destructive tests. The silos had reached their expected design life and cracks were starting to show. TALOS recommended the immediate decommissioning of two silos — one of which partially collapsed a few months later. The client required an instant response to ensure the safety of plant and people.
A method designed by TALOS engineers stabilized the silos to prevent any further collapse, in two parts: foundation and super-structure. Foundation stabilization involved pouring concrete around the base of the two critical silos; super-structure stabilization involved installing 12 metal straps around the silos to prevent any movement.
The interior walls were then reinforced from 25 m scaffolding towers erected inside the silos, giving access to the steel fixing and shotcrete crews. Finally, the roof was reinforced with steel beams lifted by crane, placed perpendicular to the existing roof beams and secured to the soffit with threaded rods and bolts.
Results
The stabilization and reinforcement were completed successfully, ensuring the silos will operate safely and effectively. Concrete silos are susceptible to extreme temperatures and external loads, so they should be inspected and maintained regularly to prevent accidents, property damage and production losses.