Measured deformations and calculated stresses of high-density polyethylene pipes under very deep burial
Bibliographic record
Abstract
The physical response of 100 mm diameter high-density polyethylene, plane-wall pipes is examined when subjected to vertical pressures as large as 3000 kPa. These pressures greatly exceed typical pressures for conventional sewer and culvert applications, but may be encountered in special applications, such as very deep tailing dams, heap-leach mining pads, and landfills. Results are presented for two different thicknesses of pipe with a diameter to thickness ratio, DR, equal to 11 and 26. Four different backfill materials are investigated, including poorly graded sand, well-graded gravel, and two poorly graded gravels. The pipes were observed to deform into essentially stable elliptical shapes with no evidence of buckling. Maximum deflections of the DR 11 pipes ranged from 10% of the initial pipe diameter at 3000 kPa for compacted poorly graded sand backfill to 20% at 2400 kPa for uncompacted angular poorly graded gravel backfill. Results from numerical analyses are also presented to provide insights into the soil and pipe response at very large pressures. Geometrically nonlinear finite element analysis featuring a viscoplastic pipe model and linear elastic–plastic model for the backfill was able to capture the measured deflections. Pipe stresses calculated from the analyses showed tensile stresses below the allowable long-term limits, but there was short-term compressive yield.
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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 | 0.000 | 0.000 |
| 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".