Zone Load Test

Input

In Situ-Comp Rel | Zone Load Test

The Zone Load Test is described in ICE Geotechnical Engineering Group Specification for Ground Treatment, 1987. The test consists of the loading and displacement monitoring of a square plate placed on the ground surface. The procedure requires visual inspections of the apparatus, precise optical levelling, and during the test a data logger is employed to record time, temperature, load, and the displacement of 4 transducers.

Two additional files are required to process ZLT tests:

  • Datgel In Situ Tool ZLT Template ##.xlt – for onsite data entry of visual inspections, precise optical levelling, and logbook remarks during loading.
  • Datgel in situ tool #.## zlt ##.gci – to assist in the import of the data logger file.

Steps to process a ZLT

  1. During preparation for a test, open a new excel file using the ZLT template. And record information on sheets Title, Logbook, Precise Levelling, Check List. The other Sheets should not be altered.

  2. Conduct the test, and a csv data logger file should be generated. The data logger file is expected in the following format.

    307,1510,-.22964,.09041,.26787,.25448,.28127,-.44199,23.067,-1.0099,30.167,0,0
307,1511,-.22964,.08706,.26787,.24109,.28127,-.44199,23.055,.00429,.4,-.0067,-.4018
307,1512,-.22964,.08036,.25448,.24109,.26787,-.44199,23.067,-1.0099,1,-.0067,-.4018
307,1513,-.22916,.08371,.26787,.24109,.26787,-.44199,23.094,-1.009,1,.00335,.2009
307,1514,-.23203,0,0,0,0,0,23.118,0,1,-.08371,-5.0226
307,1515,201.41,.76009,1.0045,1.2992,.75004,-.01339,23.13,730.26,1,.76009,45.605

    The following table is the Data Logger File Column Definition.

    Ref

    Time

    Load (kN)

    Average D (mm)

    D1 (mm)

    D2 (mm)

    D3 (mm)

    D4 (mm)

    Temp C

    Pressure (psi)

    Elapse time

    Movement since last log

    Rate of movement mm/hr

    307

    1510

    -0.22964

    0.09041

    0.26787

    0.25448

    0.28127

    -0.44199

    23.067

    -1.0099

    30.167

    0

    0

    307

    1511

    -0.22964

    0.08706

    0.26787

    0.24109

    0.28127

    -0.44199

    23.055

    0.00429

    0.4

    -0.0067

    -0.4018

  3. Import the ZLT Excel file into gINT using File > Import/Export > Import from Excel File... or Add-Ins > Datgel In Situ Tool > Data Import. If the Excel file is imported after the *.dat file or the PointID already exists, then use the over write option Empty Fields or Named Fields.

  4. Import the ZLT data logger .dat file using *Add-Ins > Datgel In Situ Tool > Data Import. Use the following settings:
    1. File Type: ZLT Data Logger (.txt; .dat)
    2. Correspondence File: ...\datgel in situ tool #.## zlt ##.gci

    3. ZLT Start Date: Set the date the test loading commenced.

      The PointID on the Zone_Load_Test (upper) table will be defined as the same name as the imported file name.

  5. Review and adjust fields on POINT, Mon-Displacement | Displacement, and IS-Comp_Rel | Zone_Load_Test.





Calculations

Average Settlement

Average of the 4 settlement transducers columns. If a value is null, then that transducer is ignored for the average calculation.

Settlement Rate (10 min) (mm/hr)

Calculated average Settlement rate over previous 10 minutes in mm/hr. If the record is within the first 10 minutes, then all preceding records are used in the calculation.

Maximum Average Settlement

Maximum average settlement for all records in Zone_Load_Test_Readings.

Specification Check

Compares the Maximum_Average_Settlement to the corresponding value in LAB_SPECIFICATION.Max_ZLT_Settlement.

Output

    • Graphs | IS ZLT AV SETTLEMENT VS LOAD CURVE (N)
    • Graphs | IS ZLT LOAD SETTLEMENT CURVE (N)
    • Graphs | IS ZLT MEASURED VS TIME (N)
    • Graphs | IS ZLT SETTLEMENT CURVE (L)
    • Graphs | IS ZLT SETTLEMENT RATE CURVE (N)
    • Graphic Text Docs | IS ZLT PRECISE LEVELLING