BLACKLAND

CPT swell

Swell from the sounding, the day of the work.

BLACKLAND reads Tip resistance and Sleeve friction from a CPT file, converts both to tsf, and applies one swell equation at each depth. Method 1 is Hampton Inn. Method 2 is HEB Irving. Value to carry is the swell supported by the stronger fit.

How to use it

Upload one sounding or a whole set. Use a Hogentogler .cpt file, or a CSV with depth, tip, and sleeve. Save an Excel file as CSV. A PDF is not read.
Read each depth. Each depth shows Method 1, Method 2, and Value to carry.
Print PDF for the sounding on screen. Print every CPT starts each sounding on its own page.

The equations, the weights, and the limits are on Info.

Upload CPT files

Hogentogler .cpt, or a CSV with depth, tip, and sleeve. Add as many files as you need. Save an Excel file as CSV first. A PDF is not read.

Information

Equations and limits

BLACKLAND reads Tip resistance and Sleeve friction from a CPT file and converts both to tsf. Each depth has one swell equation. The equation is half the tip line plus half the sleeve line. qt is the tip in tsf. fs is the sleeve in tsf. Swell is in percent.

Method 1 is the Hampton Inn set of equations. Method 2 is the HEB Irving set of equations. Value to carry is the swell supported by the stronger fit.

A dash means that swell is below zero. A depth with no line is left empty. Midlothian has no depth-band equation here.

Method 1. Hampton Inn

0 to 5 ftSwell = 0.14175 qt + 2.35 fs + 0.512
5 to 10 ftSwell = 0.0795 qt + 2.0415 fs − 3.027
10 to 15 ftSwell = 0.1205 qt + 3.106 fs − 9.2165
15 to 21 ftSwell = 0.0215 qt + 0.4935 fs + 0.5575

No combined equation below 21 ft.

Method 2. HEB Irving

0 to 2 ftSwell = 0.0465 qt + 2.076 fs + 0.511
2 to 4 ftSwell = 0.121 qt − 0.105
4 to 6 ftSwell = 0.1125 qt + 3.599 fs − 2.1245
6 to 8 ftSwell = 0.0775 qt + 2.291 fs − 0.899
8 to 10 ftSwell = 0.0465 qt + 1.193 fs + 0.2065

No combined equation below 10 ft.

Value to carry

Where both methods have a swell above zero, Value to carry is a weighted average. More tests and a higher R² give a method more weight. Where a method uses two lines, the weaker line sets its weight. Method 1 weight uses the tip fit, because a sleeve R² is not on the Hampton record.

The line under the number is that method's share of the weight. Where only one method has a swell above zero, that swell is the value to carry. Where the sleeve is missing, Value to carry uses the tip. Value to carry is shown to one decimal, and the extra part is dropped so the number is not rounded up.

A dash in Method 1 means the line came out below zero. It is not used for a missing line. Check marks a small count or the weaker line. The equation cell still shows the number and carries the same Check mark.

Limits

The binned fit misses by 3.6 percent swell. The Hampton oven line misses by 1.9 percent swell. The Hampton filter-paper line misses by 1.3 percent swell. Each miss is wider than a 1 percent specification.

The lines do not travel, and these lines do not predict the swell of one 2-foot specimen. The one-dimensional swell test replaces every number when the dials return. This page is not a heave measurement and it is not an allowable bearing. The files stay on this device.

Print

Print PDF makes a page for the sounding you are looking at. Print every CPT starts each sounding on its own page.