Helical piles in unsaturated structured soil: a case study
Bibliographic record
Abstract
The use of helical piles as tower foundations in Brazil has increased considerably during the last 5 years. A number of these piles are installed in unsaturated structured soils that cover a significant part of the Brazilian territory. However, the installation of helical piles in such soils produces a breakdown of the natural soil structure, which affects the pile performance for tension applications. This scenario motivates the present work, in which a comprehensive pile load-test program was carried out on helical piles composed of a single helix or multi-helices, installed in an unsaturated tropical residual soil. Eleven full-scale pile axial load tests were carried out, including two compression and nine tension tests. In addition, cone penetration tests were performed close to the piles after installation, and undisturbed soil samples were collected at the depth of the helices. The aim of these additional tests was to contribute to the understanding of the effect of helical pile installation on soil structure. The results of the tension load tests showed that the changes in the structure of the porous tested soil result in particularly low pile uplift capacities. In contrast, the load–settlement curves of the pile compression tests indicate a peculiar failure mechanism due to the sensitive soil structure associated with the high void ratio of the intact soil beneath the bottom plate.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.002 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".