Design and construction of a telecommunications tower foundation using micropiles

Abstract

The design and construction of a selfsupported tower (three-legged tower) foundation was performed. An existing tower affected structurally by hurricane Maria is located in a very remote location in Yabucoa, making the replacement of the tower a very challenging project. The replacement of this tower is vital for the reconstruction and re-establishment of the cellular communications in Puerto Rico. The use of micropiles was chosen because a relatively small equipment is needed to construct the micropiles. Also, the amount of material needed to complete the micropiles is small as well. This makes it a very suitable alternative for this very difficult vehicular access project. Cost effectiveness and constructability was also a very important aspect when choosing the micropiles. The geotechnical investigation, structural design and construction of the foundation supported with micropiles was successfully completed. A load test was also performed without geotechnical or structural failure. It was established that the Granodiorite Rock, geology of site and a vast area in the eastern part of Puerto Rico, is capable of developing relatively high grout-to-ground bond capacities. Important Terms  Axial Capacity, Compression Load, Geotechnical Capacity, Granodiorite Rock, Grout to Ground Bond Value, Micropiles, Pile Cap, Shear Load, Structural Capacity, Tension Load, Tension Load Test.