Standard penetration test (SPT)
Definition
An in-situ test measuring the number of blows to drive a split-spoon sampler 300 mm into the soil at a given depth. The N-value is widely used to estimate soil strength, stiffness, and liquefaction susceptibility.
Related terms
- Bearing capacity
- The maximum stress a soil or rock can sustain beneath a foundation without shear failure. Expressed as ultimate bearing capacity (at failure)...
- Cone penetration test (CPT)
- A continuous in-situ test pushing an instrumented cone through the soil and measuring tip resistance and sleeve friction. Provides a nearly continuous...
- Differential settlement
- Non-uniform vertical movement of different parts of a foundation, distorting the structure it supports. More damaging than uniform settlement because it induces...
- Liquefaction
- Loss of shear strength in saturated granular soil when earthquake-induced cyclic loading causes pore water pressure to equal the total stress, reducing...
- Piping
- Internal erosion in an embankment or foundation in which seepage flow progressively removes fine particles along a concentrated flow path until a...
Explained in
- Geotechnical and Foundation FailureAn in-situ test measuring the number of blows to drive a split-spoon sampler 300 mm into the soil at a given depth. The N-value is widely used to estimate soil...