Geotechnical Survey

Geotechnical investigation is an engineering practice to evaluate soil and rock parameters those are required for design a appropriate foundation of engineering structure. Comprehensive, precise, detail and reliable investigation can reduce construction cost, time and human safety substantially. On the other hand improper geotechnical investigation always deceives or betrays engineers and entrepreneurs. Most of the foundation designs are being done in Bangladesh on the basis of SPT N-value. Many design engineers need only SPT N-value. Due to versatility of SPT, many correlations are available, which enables engineers to estimate soil parameters like shear strength, unit weight, relative density, volume compressibility etc. It is very important to determine SPT N-value correctly, precisely without forgery and fraudulent. Improper instruments, instrumental error, human error, deliberate intentions, fabrication of data in the field by manipulation are the major cause of unreliable SPT N-values. Upon pin pointing the causes, IES introduced following activities in geotechnical investigation, which can reduce un-reliabilities:

  • Auto trip gear for releasing hammer- ensures requsit energy and precludes human error.
  • Proper instrument- precludes instrumental error.
  • Capturization video footage of SPT activity by digital camera- precludes data fabrication in field.
  • SPT N-values re-counted from captured movie.
  • Reliable lab test.

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