Tools

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Tools

Numerous tools are provided to adjust data, both during and after import.

CPT_Tools_Advanced

Start Depth

If a test starts at a point that differs from the reference point (typically ground level), the Start Depth adjustment can be used to move all data up or down.  An example of this would commonly be starting a test above ground level to collect zero readings before the actual test commenced with the depth recorder running.

Before

CPT_StartDepth_Before

After

CPT_StartDepth_After

hmtoggle_arrow1How To: Change the start depth manually

img_1 Click the Start Depth button:

CPT_Tools_DepthShift_Button

img_2 Enter a adjustment value, then click the OK button:

CPT_Tools_DepthShift_Dialog

noteNote

When the first record is:

•above the reference point, enter a negative value to remove the value from all depths

•below the reference point, enter a positive value to add the value to all depths

Predrill Depth

Sometime the first part of the test is completed through a hole (i.e. inspection pit) that has been excavated to check for services, or created using a dummy probe through material that would otherwise damage a cone.  In these cases a predrill depth is applied to remove data from the start of the test, with all values being replaced with -666 indicating a predrill zone:

Before

After

CPT_Sounding_Predrill_Before

CPT_Sounding_Predrill_After

hs-tip

This value can be set during import.

hmtoggle_arrow1How To: Set predrill depth manually

img_1 Click the Predrill Depth button:

CPT_Tools_Predrill_Button

img_2 Enter the predrill depth value required, then click the OK button:

CPT_Tools_Predrill_Dialog

hs-tip

To remove an existing value, check the Reset option.

Water Depth

Each test may have a single water depth defined, indicated by a horizontal line and a hydrostatic pressure line (hu):

Before

After

CPT_Tools_WaterLevel_Before

CPT_Tools_WaterLevel_After

If the test was completed with a piezocone, the hydrostatic pressure line should generally follow the pore pressure profile in clean sands.

If dissipation tests were completed, the hydrostatic pressure line should join the u0 markers from assessment of these tests.

hs-tip

This value can be set during import.

hmtoggle_arrow1How To: Set water depth manually

img_1 Click the Water Level button:

CPT_Tools_WaterLevel_Button

img_2 Enter the water depth value required, then click the OK button:

CPT_Tools_WaterLevel_Dialog

hs-tip

To remove an existing value, check the Reset option.

hmtoggle_arrow1How To: Set water depth graphically

img_1 Hover over the u2 chart to see a red guide:

CPT_Tools_WaterLevel_Guide

img_2 Double click the chart to set the value:

CPT_Tools_WaterLevel_After

Sleeve Offset

When data is acquired, all values are recorded based on the tip depth, with the friction sleeve located behind the tip.  As a result, the tip may be measuring data in a sand while the sleeve is measuring data in a clay.  A sleeve offset is applied align the tip and sleeve data to ensure that SBT assessments are made correctly.

CPT_Tools_SleeveOffset_Difference

Some data acquisition systems make this adjustment internally, so generated data files already contains this offset.  Its important to determine if the data contained in a file is already corrected or not.  This is best assessed by comparing rod change spikes:

Not applied in file

CPT_Tools_SleeveOffset_NotApplied

Applied in file

CPT_Tools_SleeveOffset_Applied

noteNote

To remove spikes in the fs data requires use of the sleeve shift tool, then use of the sleeve offset to to reapply the value.

hs-tip

This value can be set during import.

hmtoggle_arrow1How To: Set sleeve offset manually

img_1 Click the Sleeve Offset button:

CPT_Tools_SleeveOffset_Button

img_2 Enter sleeve offset value required, then click the OK button:

CPT_Tools_SleeveOffset_Dialog

noteNote

There's no option to reset the sleeve offset as this is a required value.

Sleeve Shift

Shifts the original sleeve data relative to tip data.

hs-tip

This value can be set during import.

hmtoggle_arrow1How To: Set sleeve shift manually

img_1 Click the Sleeve Shift button:

CPT_Tools_SleeveShift_Button

img_2 Enter the number of records to shift data, then click the OK button:

CPT_Tools_SleeveShift_Dialog