Standards

Standards

All country/code-specific content — regulation text, calculation rules, soil and slope tables, report wording, and SPDS layer names/colours — lives in standards.py behind a Standard interface. The engineering core (earthwork_core.py) and the Rhino plumbing (rhino_adapter.py) are neutral.

Three standards ship today; select one with gh_00_standard:

Code	Name	Locale	Notes
RU	СПДС (ГОСТ/СП, Россия)	ru	Default. Full implementation.
US	United States (imperial)	en-US	Cubic yards / feet, OSHA / IBC / ADA. Full implementation.
INT	International (generic, metric)	en	English layers + cut/fill report; proves the multi-country design.

---

RU — Russian SPDS (default)

Encoded editions (stamped on outputs): ГОСТ 21.508-2020 · СП 45.13330.2017 · СП 82.13330.2016 · ГОСТ Р 21.101-2020 — checked 2026-06. Cut/fill volumes are labelled м3. The cartogram uses the square method (ГОСТ 21.508-2020) with a default 20 m grid; supported drawing-grid sides are 10, 20, 25, 40, 50 m (a finer grid is allowed as a working aid but flagged as off-standard).

Soil classes

Used by the slope, frost and soil-balance tools.

Class	Soil (RU)	Soil (EN)
1	Насыпные неслежавшиеся	Fill, uncompacted
2	Песчаные	Sand
3	Супесь	Sandy loam
4	Суглинок	Loam
5	Глина	Clay
6	Лёссовые	Loess

Bulking / shrinkage factors

Кр initial bulking (loose) and Кор residual bulking (compacted), used by gh_14_soil_balance. Cut is measured in bank, fill in compacted; bank needed for fill = compacted ÷ Кор.

Class	Кр (loose)	Кор (compacted)
1	1.15	1.03
2	1.12	1.03
3	1.15	1.04
4	1.20	1.05
5	1.27	1.06
6	1.20	1.05

Indicative temporary-slope table

Allowable slope as 1:m (заложение) by excavation depth, used by gh_07_slope_check (SP 45.13330.2017, indicative). Depths over 5 m require a calculation (no indicative value). 0.0 means a vertical face is indicatively allowed at that shallow depth.

Class	≤ 1.5 m	≤ 3 m	≤ 5 m
1	0.67	1.00	1.25
2	0.50	1.00	1.00
3	0.25	0.67	0.85
4	0.00	0.50	0.75
5	0.00	0.25	0.50
6	0.00	0.50	0.50

Frost depth

Design freezing depth df = kh · d0 · √Mt, where Mt is the freezing index (sum of monthly sub-zero temperatures), kh the thermal factor (default 1.1), and d0 depends on soil. Used by gh_20_foundation_check (modelled on SP 22.13330.2016).

Class	1	2	3	4	5	6
d0, m	0.28	0.30	0.28	0.23	0.23	0.28

Other rule values

• Backfill (gh_08): working space 0.6 m, bedding 0.1 m, compaction lift 0.3 m (defaults).
• Blind area (gh_17): slope 1–10 % away from the building (СП 82.13330.2016).
• Driveways (gh_18): default max longitudinal grade 8 %; grades labelled in ‰.
• Sheet sizes (gh_23): A4 210×297, A3 420×297, A2 594×420, A1 841×594, A0 1189×841 mm.
• Title block rows: Объект · Наименование листа · Стадия / Масштаб · Лист · Разработал, дата (simplified ГОСТ Р 21.101).

SPDS layer groups

Each baking component writes onto its own named parent layer with styled child layers (colour + print weight): Картограмма земляных масс · Котлован · Разрез · Серия разрезов · Растительный слой · Рельеф · Водоотвод · Вертикальная планировка · Проезды и дорожки · Дренаж · Оформление листа.

Engineering checks never certify

The slope (gh_07) and foundation (gh_20) checks are working aids and checklists. They are never "adequate/within allowable" without geotech_confirmed, and groundwater, edge surcharge or excessive depth force a review. Every report carries a mandatory non-certification note.

---

INT — International (generic, metric)

A starter second standard that proves another country plugs in. It is metric and English: English layer names, an English cut/fill report, table and warnings, and English soil names, with no GOST drawing-grid restriction and volumes labelled m3. It inherits RU's numeric rule tables (bulking, slope, frost) as generic metric defaults. Its edition stamp openly states "generic metric defaults — no national code encoded", and its remaining report strings still inherit the Russian text (a localisation to-do).

---

US — United States (imperial)

Encoded references (stamped on outputs): OSHA 29 CFR 1926 Subpart P · IBC 2021 (frost line) · IRC R401/R403 · ADA / ICC A117.1 — checked 2026-06. Quantities are in cubic yards (CY), areas in square feet (SF), lengths in feet (ft); the reports and the baked cartogram cell tags convert from the SI the core computes (Standard.volume_factor). Layer names are English (inherited from INT).

Inputs and outputs are imperial too. Every socket is relabeled to the US unit and its numeric value converted, so names and data match the standard:

Canonical (RU)	US socket	Unit
grid_size_m, depth_m, …	grid_size_ft, depth_ft	feet
fill_m3, cut_m3, balance_m3	fill_cy, cut_cy, balance_cy	cubic yards
area_m2, plot_area_m2	area_sf, plot_area_sf	square feet
report_ru, table_ru	report, table	English text

Length inputs are converted in the component; volume/area inputs (gh_14, gh_22) and all numeric outputs are converted at the socket (Standard.socket_label / to_display / from_display). The component always reads/writes its canonical SI name, so chaining stays consistent (a US fill_cy output feeds a US cut_cy input correctly). Drop-downs are standard-aware: under US, soil_class shows OSHA Type A/B/C and sheet shows ANSI/ARCH.

Soil types (OSHA) and excavation slopes

soil_class maps to OSHA soil types. The max allowable slope is H:V for excavations up to 20 ft (OSHA 1926 Subpart P, Appendix B); over 20 ft a registered professional engineer must design the protective system.

Class	OSHA type	Max slope (H : 1V)
1	Type A (cohesive, stable)	0.75 : 1
2	Type B (medium)	1 : 1
3	Type C (granular / unstable)	1.5 : 1
4–6	Type C (conservative)	1.5 : 1

Frost depth

The foundation check compares the footing depth to the local frost line — enter frost_depth_m from the IBC / local code (a freezing-index formula is the fallback). A footing below the frost line on frost-susceptible soil is adequate (IBC 1809).

Other rule values

• Driveways / paths (gh_18): default max grade 12 %; ADA accessible route ≤ 5 %, ramp ≤ 8.33 %. Grades in %.
• Perimeter grading (gh_17): grade away from the building ≥ 5 % for the first 10 ft (IRC R401.3).
• Foundation drain (gh_21): slope to outfall ≥ 0.5 % (IRC R405).
• Sheet sizes (gh_23): ANSI A–E and ARCH A–E (default ARCH D, 36×24 in); ISO A-series also accepted.
• Bulking: swell / shrinkage per soil (indicative; confirm with the soils report).

Like RU, the slope and foundation checks are working aids that never certify — they force a review on groundwater, surcharge, over-20-ft depth, or unconfirmed geotech.

---

Provenance

Every output is traceable. The neutral tool version lives in version.py (Earthwork Studio GH v0.9.0); each standard declares the regulation editions it encodes (regulations) and when they were last reviewed (checked_on). version.provenance(standard) combines them, e.g.:

Earthwork Studio GH v0.9.0 - standard US: OSHA 29 CFR 1926 Subpart P,
IBC 2021 (frost line), IRC R401/R403, ADA / ICC A117.1; checked 2026-06

It is shown by gh_00_standard and stamped onto the sheet by gh_23_titleblock. The stamp records the encoded editions; it does not replace engineer review.

---

Adding a country

1. Subclass Standard (or RussianStandard to reuse its numeric tables) in standards.py. Set code, name, locale, regulations, checked_on and volume_label.
2. Override only the rules, report text and layer groups that differ.
3. Register it in the STANDARDS dict.

No changes to the core, the adapter, or the 20 components are needed — they read the active standard through standards.get_standard(), which honours the gh_00_standard selection.