Entering field readings
The readings table, calculated columns, observations and field notes.
The Field readings table is the heart of a DCP test.
How it works
Enter the number of blows for each interval. The next depth is prefilled at 150 mm and stays editable, so you can shorten an increment for partial penetration or refusal.
The columns
| Column | Entered or calculated |
|---|---|
| # | Row number |
| Blows + | You enter — blows for this increment |
| Cumulative | Calculated — running blow total |
| Scale reading mm | You enter — the reading at the end of the increment |
| Penetration mm | Calculated — penetration over this increment |
| DCPI mm/blow | Calculated — penetration per blow |
| Est. CBR % | Calculated — CBR estimated from DCPI |
| Observation | You choose — Normal or another condition |
| Field note | You enter — refusal, material change, anything unusual |
Reading the results
DCPI (mm/blow) is the raw measure of resistance: a low value means stiff material, a high value means soft. Est. CBR % converts that into a bearing ratio for each increment.
Observations and field notes
Use the Observation dropdown and Field note whenever the increment isn't routine. Refusal on a cobble, a sudden change in material, water in the hole — these explain anomalies in the profile that would otherwise look like errors when the test is reviewed months later.
The prompt text in the field note column — Refusal, material change… — is a reminder of what belongs there.