Mitigation of frost heave around manholes: a proven innovation
Bibliographic record
Abstract
Deformation and cracking of asphalt pavement around sanitary and storm sewers are major and costly problems in northern cities all over the world. The main cause of this pavement deterioration is frost heave, which can lead to a substantial uplift of pavement (5 to 10 cm), as well as to cracking of the asphalt surface around manholes. This paper describes an innovation developed by Otto J. Svec with the trade name GHM-RAD, that prevents freezing temperatures (the 0°C isotherm) from moving below the pavement structure down to the frost-susceptible soil, thereby controlling frost heave around access hole structures. This new technology is a closed system that modifies the top taper cone section of a manhole by casting slots into its walls. This section is installed surrounded by a donut-shaped bag made of geotextile and containing clean, 51 mrif aggregate. Temperature readings revealed warm sewer air circulated out through the slots and around the "radiator bag". This transferred heat energy kept the ground below the bag from freezing. With the assistance of the City of Ottawa, two field studies monitored four test sites and two control sites during the winters of 1998-1999 and 2000-2001. Thermocouple readings have provided consistent and conclusive evidence that this innovation prevented freezing temperatures from moving into the frost-susceptible soil during two winters. Also, inflow and infiltration concerns were considered in the second field study and preliminary results indicate additional water inflow through the slots might not be a concern with this innovation.
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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 | 0.002 |
| 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 | 0.002 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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 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".