Numerical Simulation of Mitigation of Soil Swelling Problem under Communication Tower Using Helical Piles

Abstract

Abstract Expansive soils exhibit significant volume changes with variations in soil moisture content. Expansive soils are often considered as problematic soils. It undergoes large volume changes upon wetting and drying and causes huge damages to the structures resting on it. Numerical modeling was carried out by using PLAXIS 3D-2013 software, in which modeling the soil by using hardening soil model was done. Tower rested on expansive soils are subjected to uplift and lateral forces due to soil swelling and wind load. More importantly, the swelling in expansive soil tends to cause additional lateral pressure on foundation of tower that caused deformations and bending. Various pattern types of helical piles are used to reduce the vertical and lateral movement of tower constructed on expansive soil. This study showed that to reach zero uplift movement of tower foundation constructed on expansive soil need L/D ratio 118, 113 and 102 for helical piles group of (2×2), (3×3) and (4×4) respectively with single and double helix plates in the upper and lower part of helical pile. To reach zero uplift movement of tower founded on expansive layer, L/H ratio should be penetrated (1.52, 1.37, 1.20) for helical piles group of (2×2), (3×3) and (4×4) respectively with single and double helix plates in the upper and lower part of helical pile. In general, the presence of helical piles below tower foundation resisted and controlled the vertical movement and lateral movement. Keywords: Helical pile, expansive soil, tower, uplift movement Cite this Article Bushra Suhale Al-Busoda, Hassan Obaid Abbas. Numerical Simulation of Mitigation of Soil Swelling Problem under Communication Tower Using Helical Piles. Journal of Geotechnical Engineering. 2017; 4(3): 35–46p.