Communication Towers

Strengthening of Cell Phone Communication Towers with PileMedic®

The following case study demonstrates how concrete or steel towers can be strengthened in a fast and safe manner with a patented PileMedic® System developed by Professor Mo Ehsani.The particular tower shown is a monopole structure located in a high seismic zone in Southern California. It is nearly 55 feet (17m) tall. The tower is made of a hollow spun precast concrete tube with a thickness of less than 2 inches (50mm). Our analysis indicated that the entire tower height required tension reinforcement. In addition the concrete wall for the lower half of the tower was too thin, requiring a thicker concrete to resist the load safely.

View More Case Studies involving PileMedic®:

Restoration of Structurally Deficient Bridge Piers for Missouri DOT

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Repair of Deteriorated UnderwaterPiles in Miami, FL

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Repair of Corrosion Damaged Steel Columns for Tucson Electric Power Company

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Tests of Earthquake-Damaged Concrete Bridge Piers by Caltrans and NSF

1. 14 feet (4.25m) deep holes with a diameter of 1.25 inches (32mm) were drilled into the foundation. Steel reinforcing bars were epoxy anchored into these holes and extended above the foundation. Such deep drilling is not common in all our repairs but it was required at this specific site.

2. One layer of Quakewrap® unidirectional carbon fabric saturated with Quakebond™ epoxy was bonded in vertical bands to the entire height of the tower.

3. A second layer of the same carbon fabric was applied to the lower two thirds of the tower height.

4. The entire height of the tower was wrapped with resin saturated glass fabric in horizontal bands.

5. A PileMedic® jacket was used to create a reinforcing shell around the lower 4 feet (1.2 meters) height of the tower, encaging the steel reinforcing bars. The 6-inch (150mm) annular space was filled with an expansive non-shrink grout.

6. Several PileMedic® jackets were used to create a shell with an angular space of 1.5 inches (38mm) from the height of 4 feet (1.2m) to a height of 16 feet (4.9m). The base region was filled with an expansive non-shrink grout.

7. As part of this repair a number of existing cables and conduits that were patched to the tower were carefully moved slightly to accomodate the repairs. This did not require disconnecting any of these cables, allowing the tower to remain fully in service during the repair. These appurtenances were later pushed back to their original location.Field installation of this project was completed by FRP Construction LLC, Tucson AZ.