The Standard Penetration Test (SPT) is a common and inexpensive test that provides many benefits for determining the properties of soil:

 The Standard Penetration Test (SPT) is a common and inexpensive test that provides many benefits for determining the properties of soil: 

Simple: The SPT is a simple and quick test to perform. 

Inexpensive: The SPT is a relatively inexpensive test. 

Useful in many situations: The SPT is useful in situations where more advanced laboratory testing is not practical, such as in gravelly, sandy, silty, sandy clay, or weak rock formations. 

Provides approximate soil strength parameters: The SPT provides approximate soil strength parameters, such as relative density, bearing capacity, and settlement. 

Provides soil samples: The SPT provides a disturbed soil sample that can be used to identify and classify the soil type, and determine moisture content. 

Provides data on soil behavior: The SPT-N values can reflect how soil behaves during earthquakes. 

Provides data on shear strength: The SPT provides data on the angle of shearing resistance of cohesion-less soils. 

Provides data on compressibility: The SPT provides data on the compressibility of soil.