Basis for recommending an update of wind velocity pressures in Canadian design codes
Bibliographic record
Abstract
Reference wind velocity pressures corresponding to specified return period wind speeds are provided in several Canadian design codes. A review of the two most recent editions of the National Building Code of Canada (NBCC) indicates that significant changes in some 50-year return period wind speeds, vAH-50, were introduced in the 2010 version of the NBCC-2010 compared to the previous NBCC-2005. The changes are due to analysis approaches, available wind records, and a re-examination of anemometer histories. To potentially improve the estimates of vAH-50, wind records in the Environment Canada HLY01 digital archive were processed. Two hundred and thirty-five meteorological stations are considered in the analysis, and height and exposure corrected annual maximum hourly-mean wind speed, VAH, are extracted. Statistical analysis and distribution fitting were carried out using the Gumbel distribution and generalized extreme value distribution and several fitting methods were employed. The results indicate that it is preferable to treat VAHas a Gumbel variate, and to carry out the fit using the generalized least-squares method. Wind speed contour maps for Canada are developed based on the estimated vAH-Tfor T equal to 50, 500, and 1000 years. A comparison of the maps of vAH-50to those inferred from NBCC-2005 and NBCC-2010 shows that the developed map retains some of the smoothness of the wind speeds exhibited in NBCC-2010, while maintains the localized wind speed features presented in NBCC-2005. Results also show that the wind speed corresponding to the factored design wind load in NBCC-2010 is associated with a return period ranging from 200 to 5000 years, but for 90% of stations considered, the range narrows to 300 to 900 years.
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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 | 0.009 | 0.067 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.014 | 0.015 |
| Science and technology studies | 0.004 | 0.002 |
| Scholarly communication | 0.004 | 0.003 |
| Open science | 0.005 | 0.002 |
| Research integrity | 0.002 | 0.004 |
| Insufficient payload (model declined to judge) | 0.013 | 0.008 |
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".