Hesselø OWF–Preliminary geotechnical site investigation –Fast track tri-axial test results 1/2

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Date:3. august2021

Author:XMAFO/SMT/JRA

HESSELØ OWF – PRELIMINARY GEOTECHNICAL SITE

INVESTIGATION – FAST TRACK TRI-AXIAL TEST

RESULTS

1. Introduction

The first indications from the preliminary site investigations at Hessel OWF site indicated soft

clay sediments. Toinvestigate this further a fasttracklaboratory test program were initiated

with 80 samples,selected from the identified soft post glacial clay sediments.

This note presents the test results for the 80undrained -unconsolidated tri-axial compression

tests on postglacial normally consolidated clay deposits from Hesselø OWFsite.

The full content of the laboratory test results is attached as an Excel file, in AGS 4.0 format. The

unit of TRIT_CU is kPa.

Samples included in present dataset originates from the top 35 meters belowthe seabed rep-

resenting the boreholesillustrated in Figure 1 and listed in the attached data file.

Figure 1 Borehole positions within the Hesselø OWF site.

Hesselø OWF – Preliminary geotechnical site investigation - Fast track tri-axial test results 2/2

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2. Test results

The undrained – unconsolidated tri-axial tests have been completed at confining pressures

equivalent to in-situ stress level for the individual sample. The test results have been identified

at peak shear stress below 20% strain. Variations in undrained shear strength test results are

illustrated in Figure 2.

Figure 2 Fast track test results for undrained shear strength vs. depths for post glacial deposits.

Above test results has been correlated with CPT findings from the adjacent CPT.

Correlations with CPT readings are illustrated in Figure 3.

Figure 3 Fast track test results for undrained shear strength vs. net cone resistance for post gla-

cial deposits.