Effect of Backfill Temperatures on Axial Restraint of Pipelines
Bibliographic record
Abstract
One consideration for pipeline design is the Delta-T. There may be a tendency to assume a conservative value for winter construction, the extreme value being the air temperature. In applying a low restraint temperature in winter, the Delta-T is increased. The consequence of an artificially high Delta-T is that the pipeline may notionally experience high stresses; in extreme cases, mitigation is required to counteract these stresses. In winter, the soil at pipeline depth will usually be unfrozen or slightly frozen. When a pipeline nominally at ambient air temperature is backfilled, the warmer backfill soil will quickly warm the pipeline steel from the air temperature to a more moderate temperature. As a result, the pipeline is unlikely to attain full axial restraint at low air temperatures but instead at more temperate temperatures. In contrast, for pipelines constructed in summer and assumed to be backfilled at warm air temperatures, the resulting Delta-T may be nonconservative, particularly for hot pipelines. This paper presents the test results for several pipelines installed in winter and summer. The pipelines were instrumented with thermistors to monitor pipeline and soil temperatures and strain gauges to monitor pipeline strains during the backfilling process. Guidance is provided as to appropriate tie-in temperatures.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".