Soil classes and categories

groundhog.siteinvestigation.classification.categories.relativedensity_categories(relative_density, **kwargs)

Categorizes relative densities according to the following definition:

• 0 - 0.15: Very loose

• 0.15 - 0.35: Loose

• 0.35 - 0.65: Medium dense

• 0.65 - 0.85: Dense

• 0.85 - 1: Very dense

Parameters:

relative_density – Relative density of cohesionless material (\(D_r\)) [\(-\)] - Suggested range: 0.0 <= relative_density <= 1.0

\[D_r = \frac{e - e_{min}}{e_{max} - e_{min}}\]

Returns:

Dictionary with the following keys:

• ’Relative density’: Relative density class

Reference - API RP2 GEO

groundhog.siteinvestigation.classification.categories.samplequality_voidratio_lunne(voidratio, voidratio_change, ocr, **kwargs)

Determines the sample quality for clays based on the change in void ratio when consolidating the sample back to the initial vertical effective stress. The classification is based on testing of soft marine clays sampled with different methods.

OCR	\(\Delta e / e_0\)
	Very good to excellent	Good to fair	Poor	Very poor
1 - 2	< 0.04	0.04 - 0.07	0.07 - 0.14	> 0.14
2 - 4	< 0.03	0.03 - 0.05	0.05 - 0.10	> 0.10

Parameters:

• voidratio – Initial void ratio (\(e_0\)) [-] - Suggested range: 0.3 <= voidratio <= 3.0

• voidratio_change – Change in void ratio when consolidating to in-situ stress (\(\Delta e\)) [-] - Suggested range: -1 <= voidratio <= 1

• ocr – Overconsolidation ratio (\(\text{OCR}\)) [-] - Suggested range: 1 <= voidratio <= 4.0

Returns:

Dictionary with the following keys:

• ’delta e/e0 [-]’: Ratio used for classification

• ’Quality category’: Quality category according to Lunne et al.

Reference - Lunne, T., et al. “Effects of sample disturbance on consolidation behaviour of soft marine Norwegian clays.” Geotechnical and geophysical site characterization: proceedings of the third international conference on site characterization ISC. Vol. 3. 2008.

groundhog.siteinvestigation.classification.categories.su_categories(undrained_shear_strength, standard='BS 5930:2015', **kwargs)

Classifies undrained shear strength in a number of categories. The classification system can be selected but the default is BS 5930:2015. Classification according to ASTM D-2488 is also available.

According to BS 5930:2015:

• Extremely low: < 10kPa

• Very low: 10 - 20kPa

• Low: 20 - 40kPa

• Medium: 40 - 75kPa

• High: 75 - 150kPa

• Very high: 150 - 300kPa

• Extremely high: > 300kPa

According to ASTM D-2488:

• Very soft: 0 - 12.5kPa

• Soft: 12.5 - 25kPa

• Firm: 25 - 50kPa

• Stiff: 50 - 100kPa

• Very stiff: 100 - 200kPa

• Hard: 200 - 400kPa

• Very hard: > 400kPa

Parameters:

• undrained_shear_strength – Undrained shear strength of the cohesive sample (\(S_u\)) [\(kPa\)] - Suggested range: 0.0 <= undrained_shear_strength <= 1000.0

• standard – Standard used for the classification (optional, default= ‘BS 5930:2015’) - Options: (‘BS 5930:2015’, ‘ASTM D-2488’)

Returns:

Dictionary with the following keys:

• ’strength class’: Strength class for the selected classification system

Reference - BS 5930:2015, ASTM D-2488

groundhog.siteinvestigation.classification.categories.uscs_categories(symbol, **kwargs)

Provides the verbose description for soil type codes according to USCS. The USCS_DICTIONARY can also be used in workflows.

Parameters:

symbol – Two character symbol for the soil type according to USCS

Returns:

Dictionary with the following keys:

• ’Soil type’: Verbose description of the soil type

Reference - USCS