Determination of Canadian Seismic Force Modification Factors for Post-Tensioned Cross-Laminated Timber Rocking Walls
Bibliographic record
Abstract
Post-tensioned cross-laminated timber (PT-CLT) rocking walls with energy dissipation devices (EDDs) have proved to be a low-damage seismic force–resisting system (SFRS) due to their self-centering capability and stable energy dissipation. Global efforts have been made to explore the applicability of PT-CLT walls as primary SFRS in mass-timber buildings. Studies have demonstrated satisfactory performance of such systems in high seismic risk zones in Canada. Nonetheless, challenges remain for this system to be practically adopted in Canada due to the absence of SFRS force modification factors (overstrength-related factor, Ro, and ductility-related factor, Rd) in the latest editions of the National Building Code of Canada (NBC). This study evaluates Rd and Ro factors for PT-CLT rocking walls with EDDs following the performance-based unified (PBU) procedure and FEMA P695. The PBU procedure is used to assess system performance against life safety and collapse prevention performance levels, whereas global collapse analysis is conducted following FEMA P695. An Ro of 1.5 and three trial Rd factors, Rd=3, 4, and 5, were initially considered. To reflect potential variability in building geometry, system configuration, and seismic hazards, 75 archetype buildings were designed using each Rd factor, leading to 225 archetype buildings in this study. A robust multispring numerical modeling strategy in OpenSeesPy was first validated with full-scale quasi-static cyclic and shaking table tests and then used to model all archetype buildings. Nonlinear static analysis was first conducted to validate the Ro factor, followed by nonlinear response history analyses and incremental dynamic analyses to validate trial Rd factors by examining building performance and collapse margin ratios. The investigation indicated that an Ro of 1.5 and an Rd of 4 could make all designed archetype buildings satisfy the acceptance criteria of both the PBU procedure and FEMA P695.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".