What is soil penetration testing?
What is soil penetration testing?
The Standard Penetration Test (SPT) is a common in situ dynamic testing method used to determine the geotechnical engineering properties of subsurface soils. It is a simple and inexpensive test to estimate the relative density of soils and approximate shear strength parameters.
What is standard penetration test?
Standard Penetration Test (SPT) is a simple and low-cost testing procedure widely used in geotechnical investigation to determine the relative density and angle of shearing resistance of cohesionless soils and also the strength of stiff cohesive soils.
What is N value SPT?
The purpose of conducting SPT is to obtain the standard penetration resistance, commonly called the N value, which is the recorded blow count needed to advance through a 150 mm interval of soil.
What is the use of SPT N value?
The SPT (N) value provides information regarding the soil strength. SPT (N) value in sandy soils indicates the friction angle in sandy soils and in clay soils indicates the stiffness of the clay stratum.
Is code for standard penetration test of soil?
The code was revised in 1981, in which the mass of the drive weight was changed to 63.5 kg from 65 kg and the sampler specifications were changed by introducing a new standard—IS 9640 [7].
How is SPT calculated?
SPT N value for cohesive soils with r 2 as 0.998 is represented by following equation.
- C = – 2
How do you determine the N value of soil?
The sampler is 51 mm O.D. (outside diameter) and it is driven into the soil with a 63.5 kg weight having a free fall of 760 mm. The first 150 mm of soil is neglected. The next 300 mm of soil constitutes the test. The number of blows for that 300 mm becomes the N-value.
What are the three 3 Atterberg limits?
3 Atterberg Limits. There are three important Atterberg limits: shrinkage limit (SL), plastic limit (PL), and liquid limit (LL). The shrinkage limit is the water content at which the volume of the soil starts to increase.
Is high plasticity clay good?
A high PI indicates an excess of clay or colloids in the soil. Its value is zero whenever the PL is greater or equal to the LL. The plasticity index also gives a good indication of compressibility (see Section 10.3). The greater the PI, the greater the soil compressibility.
