Mine Tailings CPTu soundings — curated Parquet for the conic library

Curated CPTu subset of mine tailings cone penetration soundings (Arnold & Macedo, 2023), prepared as an analysis-ready Parquet file for the conic library. The source database compiles laboratory and field tests on mine tailings; its cone penetration (CPTu) records were extracted for the 16 materials carrying field-scale data and assembled into a single piezocone file, retaining the measured inputs (depth, tip resistance, sleeve friction, pore pressure u2). The source tip is the pore-pressure-corrected qt; the uncorrected qc was recovered as qc = qt − u2 · (1 − a), using the per-sounding cone area ratio, and stored under the qc name for cross-dataset consistency. Cleaning steps: rows at exactly equal depth within a sounding collapsed to one by averaging the measurements; negative sleeve friction (fs) truncated to zero; rows with no usable cone reading dropped; depth resets from re-drives removed. Because the source does not supply in-situ stresses, vertical stresses were derived under a simplifying assumption of a single saturated unit weight per sounding and a hydrostatic water table: σv_tot = γ · z, u0 = γw · max(z − zw, 0), σv_eff = σv_tot − u0. The unit weight γ was taken from the median consolidated density of each material's cyclic simple shear specimens (interpreted as saturated, as the source does not specify); materials lacking a density were assigned the pooled median of same-ore materials. The measured pore pressure (u2) is retained as a separate column. A dense per-file key (Sorted ID) was assigned while preserving the source identifier (Original ID, with "_" rendered as "-"); the ore type was kept as a sentence-cased Ore column (the per-sounding grouping label); and the per-sounding cone area ratio was added as Area ratio (-). The file is sorted by sounding and depth and stored as zstd-compressed Parquet. This curated derivative is released under CC BY 4.0. Changes are limited to extraction, cleaning, qc recovery, stress derivation, re-keying, and format conversion. Original dataset: Arnold, C., Macedo, J. (2023). A Novel Experimental Database on the Cyclic Response of Mine Tailings. DesignSafe-CI. https://doi.org/10.17603/ds2-1k0a-dt17