Skip to content
Civil Vedant

Civil Vedant

The Online Civil Engineering Portal

  • Articles
    • Materials & Construction
    • WRE & Irrigation
    • Geotechnical
    • Transportation
    • Environment
    • Safety
  • Multiple Choice Questions
    • Civil Engg.
    • Materials
    • Environment Engg.
    • Fluid Mechanics
    • Soil Mechanics
    • Structure
    • Survey
    • Hydrology & Irrigation
    • Transportation Engg.
  • Jobs
  • Toggle search form
SPT

Standard Penetration Test

Posted on March 3, 2021March 3, 2021 By Civil Vedant

Standard Penetration Test (SPT) is an in-situ test, used to determine the relative density and angle of shearing resistance of cohesionless soils. This test is also used to determine Unconfined Compressive Strength (qu) of cohesive soils.

The test employs a split-spoon sampler which consists of a driving shoe, a split-barrel of circular cross-section which is longitudinally split into two parts and a coupling.

SPT is done as per following procedure :

  1. The borehole is advanced to the required depth and the bottom is cleaned.
  2. The split-spoon sampler is driven into the soil by a drop hammer of 65kg falling through a height of 750 mm. [ Rate of blows = 30 blows/min]
  3. The number of blows (N) for every 150 mm penetration is recorded.
  4. The above step(3) is done for 2 more times.
  5. The “N” value for 1st penetration is discarded as it is a seating drive.
  6. The total value of “N” for 300 mm penetration is Standard Penetration Value.

Corrections applied in SPT value :

  1. Overburden Pressure Correction :

2. Dilatency Correction :

SPT test is halted, if :

  1. 50 blows are required for any 150 mm penetration.
  2. 100 blows are required for 300 mm penetration.
  3. 10 successive blows produce no advance.
Share
Geotechnical Tags:SPT, SPT Test, spt test correction, spt test of soil, spt test report, spt test soil, Standard Penetration Test, Standard Penetration Test IS Code, Standard Penetration Test of Soil, Standard Penetration Test Procedure

Post navigation

Previous Post: Lime and its types
Next Post: Diversion Head Works – Purpose & Components

More Related Articles

soil investigation What is Soil Investigation and how it is done? Geotechnical
index properties of soil Index Properties of Soil (Basics) Geotechnical
triaxial test Triaxial Test – An Overview Geotechnical
earthquakae Hazards related to Geotechnical Engineering due to earthquakes Geotechnical
numerical modelling Applications of Numerical Modelling in Geotechnical Engineering Geotechnical
compaction vs consolidation in geotechnical engineering Compaction vs Consolidation Geotechnical
  • Home
  • Disclaimer
  • Privacy Policy
  • Contact Us
  • About
  • DMCA

Copyright © CivilVedant. All Rights Reserved. All logos and trademarks belong to their respective owners.

Copyright © 2023 Civil Vedant.

Powered by PressBook Blog WordPress theme