Geotechnical Surveys

Geotechnical survey is a prerequisite for any type of underwater construction, from peers, oil rigs to cable and pipeline lying operations. Depending on the survey specifications, gravity core or vibrocore samplers may be used for collecting undisturbed samples from the desired depth. Grab Sampler is used to get sediment samples from the sea floor.

Samples are subjected to tests such as grain size, atterberg, unconfined compression, triaxial strength, unconfined shear, water content, specific gravity natural unit weight. Collected samples are tested in accredited laboratories in order to evaluate the geotechnical structure of the survey site. Collected data is then correlated with geophysical survey results in order to make interpretation of all geotechnical and geophysical data of the survey site.

Some of the tests DERINSU carries out are as follows:

COHESIONLESS MATERIAL

Determination of:

  • Natural unit weight
  • Water content
  • Specific gravity of grains
  • Max. and min. density
  • Relative density
  • Carbonate content
  • Organic content
  • Permeability
  • Grain size analysis
  • Cyclic triaxial test

COHESIVE MATERIAL

  • Natural unit weight
  • Water content
  • Specific gravity of grains
  • Atterberg limits
  • Carbonate content
  • Organic content
  • Grain size analysis
  • Index shear strength tests
  • Determination of:
  • Undrained shear strength
  • Sensitivity
  • Constant rate of strain consolidation test
  • Triaxial test
  • Cyclic Direct Simple Shear Tests

ROCK

  • Unit weight
  • Unconfined uniaxial compression test
  • Point load test