Response of Intermediate Foundations for Onshore Wind Energy Under Variable Ground Conditions-PPT Presentation

PPT Presentation

Pdf Summary

The presentation examines how variable ground conditions affect intermediate foundations for onshore wind turbines. As wind projects span large areas, designers must balance using a consistent foundation design across many turbine locations against tailoring designs to local soil conditions.<br /><br />The study modeled a reinforced-concrete cylindrical foundation in PLAXIS 3D. The foundation was 32 ft deep, with a 16-ft outer diameter and a 12-ft inner diameter. Eighteen ground profiles were considered, representing sand- and clay-dominated conditions with differing soil-layer depths. Soil behavior was modeled using the Hardening Soil constitutive model with a Mohr–Coulomb failure criterion. The analysis simulated soil initialization, foundation installation, prestressing, tower and nacelle installation, and a lateral pushover.<br /><br />The results compare foundation-edge displacements, applied moment versus rotation, and rotational stiffness across the profiles. The presentation emphasizes that soil-profile selection can meaningfully affect predicted foundation behavior, making careful selection of representative design profiles essential. It also identifies rotation, rather than bending, as the dominant aspect of pier behavior.<br /><br />The analysis has limitations: groundwater effects and undrained conditions were not considered, the modeled soils were relatively competent, and the range of ground profiles was limited. Future work should examine spread and other intermediate foundations, include groundwater and undrained behavior, and assess additional profiles to better identify where changes in foundation response occur.

Keywords

onshore wind turbines

intermediate foundations

variable ground conditions

reinforced-concrete cylindrical foundation

PLAXIS 3D

Hardening Soil model

Mohr-Coulomb failure criterion

soil profiles

rotational stiffness

foundation displacement