Soil Dynamic Response for Seismic Microzonation Purposes: Rancagua-MachalÍ and Rengo Cities, Chile.
Bibliographic record
Abstract
Summary Seismic microzonation maps for Rancagua, Machalí, and Rengo cities, located in the Cachapoal basin, Central Chile, were generated based on near-surface geology, well stratigraphy, and soil dynamical properties. In the past, these urban areas have suffered severe damage due to earthquakes occurrence. Cachapoal basin sedimentology predominantly consists of alluvial deposits; at the Cordilleran foothills, in Machalí, volcanic ash deposits (Pudahuel Ignimbrite) crop out. A total of 50 microtremor measurements at Rancagua-Machalí and 22 at Rengo were used to compute the predominant frequency using horizontal to vertical spectral ratio (HVSR); spatial autocorrelation and F-K techniques were used to obtain Vs velocity profiles. Results show a good correlation with near-surface geology; we defined 3 different types of soil, type A, associated with the presence of volcanic ash deposits; type B a transitional zone, and type C that can be linked with fluvial deposits, mainly gravel and dense sand deposits. The Vs map of Rengo shows an interesting pattern which decreases from east to west and could be related to the presence of finer sediments to the west of the area, although no changes of near surface geology are observed. Available maps are key products for seismic risk assessment and urban planning.
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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 | 0.000 | 0.000 |
| 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) | 0.003 | 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".