proctor_fit: Fit a compaction curve

In evanmascitti/soiltestr: Functions for Laboratory Soil Testing

Fit a compaction curve

Description

\lifecycle

maturing \loadmathjax The compaction curve is fit using a natural cubic spline and optimized to find D_{max} and w_{opt}.

Usage

proctor_fit(df, spline_degree = 3)

Arguments

df	A tibble containing raw compaction data containing (at a minimum) columns "water_content", "filled_cylinder_mass_g", "empty_cylinder_mass_g", "cylinder_vol_cm3"
spline_degree	The number of terms in each piece-wise polynomial spline (defaults to 3). May not exceed more than n-1 where n is the number of compaction cylinders tested.

Details

The values of \mjseqnw_opt and \mjseqn\rho_max are computed by an optimization of the the spline function, see stats::optimize().

Value

A list with 5 elements:

• physical_props a tibble containing the cylinder number, the water content, and the computed physical properties for each specimen:

• moist density

• dry density

• total porosity

• void ratio

• effective saturation

Note: porosity is calculated using the specific gravity contained in the required Gs column of the data frame passed via df.

• proctor_model S3 object returned by a call to lm

• proctor_function R bytecode function derived from proctor_model

• w_opt The optimum water content for the present compaction effort

• d_max The maximum dry density for the present compaction effort

References

Proctor, 1932. Description of field and laboratory methods. _Eng. News Record-, 110:10, p. 286-289.

Standard effort: ASTM D698-12e2

Modified effort: ASTM D1557-12e1

See Also

generate_proctor_datasheet(), proctor_prep(), mix_calcs(), stats::optimize()

Examples

std_eff <- dplyr::filter(example_proctor_data, compaction_effort == 'standard') %>%
  add_physical_properties()
proctor_fit(std_eff)

evanmascitti/soiltestr documentation built on Oct. 6, 2022, 5:32 p.m.