# Problems with Swell/Consolidation Time-Rate Curves

## Specific Time-Rate Curves Not Showing on Reports

There are two possible reasons why the time-rate curve is not included in
hardcopy reports:

- You unchecked the
**Report** box at the right of the specific time-rate
curve.
- The program was unable to calculate a C
_{v} value for the
corresponding loading increment (increments without valid C_{v} results are not included on time-rate reports). If the C_{v} value shown in the
time-rate curve display's status window reads `n/a`

then the
program could not calculate a valid C_{v} value -- this is usually due
to a problem with the adjustment of the C_{v} construction lines.

## C_{v} Value in the Time-Rate Curve Status Window Shows `n/a`

For some datasets, the profile of the time-rate curve, or the adjustment of the curve's C_{v} constructions, can
result in a situation where the software cannot calculate a meaningful
C_{v} value. Specific problems depend upon the curve type being plotted:

**LOG(time) Curves:** CONS calculates the D_{100} value as the
dial reading at the intersection of the two construction lines. Next,
D_{50} is calculated as (D_{100}+D_{0})/2: if
D_{50} falls before the first point on the curve, CONS can't calculate
a C_{v} value.

To check for this problem, calculate D_{50} based upon
the D_{0} and D_{100} values shown in the log(time) window's
calculation results panel, and match this against the dial reading at point 2
in the data entry window.
**SQR(time) Curves:** The usual reason why a C_{v} value isn't
reported is because the program was not be able to calculate a valid
T_{90} point - this point is the intersection of the curve and the
rightmost of the two construction lines and is indicated by a green vertical
line. If the vertical line is missing, then the rightmost construction line
does not intersect with the curve. (In certain situations, this line falls to
the left of the first curve point.) The solution is to adjust the construction
lines until the vertical T_{90} indicator is displayed.