Evaluation of Becker penetration test interpretation methods for liquefaction assessment in gravelly soils
Bibliographic record
Abstract
The Becker penetration test (BPT) is the only tool available for characterizing gravelly soils with a probe diameter that is meaningfully larger than that of the standard penetration test (SPT) and the cone penetration test (CPT). Measurements on the BPT system during operation provide information on how penetration is controlled by the driving energy and frictional resistance along the shaft. This has led to development of the instrumented Becker penetration test (iBPT), which uses measurements of force and acceleration obtained directly behind the drill string tip to compute the residual energy and displacement induced by each hammer blow. These measurements are used to produce a continuous profile of normalized blow counts that are repeatable, unaffected by varying driving energy or accumulated shaft resistance, and can be used to directly estimate equivalent SPT N 60 blow count values as per DeJong et al. and Ghafghazi et al. in their 2017 studies. The measurements obtained also enabled evaluation of previously developed methods by Harder and Seed in 1986 and Sy and Campanella in 1994. This evaluation revealed that the hammer energy normalization approaches employed by Sy and Campanella and especially Harder and Seed are not robust across the broad range of conditions observed. The predicted equivalent SPT N 60 values by Harder and Seed and Sy and Campanella methods are influenced by the shaft resistance magnitude as both methods are based on above-ground field measurements. Estimated N 60 values produced by the two methods can be inconsistent with each other, with N 60 values produced by the iBPT, and with measured N 60 values obtained directly from SPT (where values are obtained in the absence of gravel).
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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 | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".