Introduction to Seismic CPT Testing

CPT Testing

What is Seismic Cone Penetration Testing?

Seismic CPT or SCPT is a technique for ascertaining the little strain shear modulus of the dirt by estimating shear wave speed through the dirt. The little strain modulus is a critical amount for deciding the dynamic reaction of soil amid tremors, unstable explosions, vibrations from apparatus, and amid wave stacking for seaward structures. The wave velocities and moduli got from seismic CPT test help in the assurance of soil liquefaction potential and improve the understanding of surface seismic overviews by giving wave speed profiles as a component of profundity. Seismic waves from SCPT tests have been distinguished at profundities of up to 300 feet.

How can it work?

SCPT testing is executed as a feature of a typical CPT or CPTU test. Gear comprises of a CPT rig, push framework, and:

SCPT Cone: The SCPT cone is a CPT or CPTU cone that is outfitted with at least one geophone sensors. These sensors measure the extent and landing time of seismic shear and pressure waves.

Wave Generator: Seismic shear waves are produced at the dirt surface in one of two different ways:

SCPT Hammer and Electronic Trigger

The least complex strategy is to press a steel bar onto the ground the long way utilizing the heaviness of the CPT rig, at that point strike the finish of the bar with an extensive sledge. An electronic trigger joined either to the sledge or the bar records the specific time of the strike.

Another strategy utilizes an electronic wave generator connected to the CPT rig. This technique expands repeatability and diminishes physical strain and testing time for the field group.

The CPT test must be delayed quickly at the ideal interims to play out the wave age and information accumulation. These delays might be utilized to direct a pore weight dispersal test too.

Information Acquisition System: As seismic waves are enrolled by the geophone sensors, information is exchanged from the cone to the dirt surface by wires that run however the push bars. The SCPT information obtaining framework logs this information and investigates it to decide the speed of the waves dependent on their entry time and the separation between the wave generator and the sensors. At long last, the wave speed is utilized to ascertain shear modulus, soil liquefaction chance and different parameters.

Adding seismic testing to your CPT test is basic and practical in the event that you have the correct hardware. Seismic innovation is a necessary piece of CPT frameworks: all our advanced CPT cones contain coordinated double hub or tri-pivotal geophone sensors, information procurement framework is completely good with seismic information. In this manner, seismic testing requires negligible set-up time past what is required for an ordinary CPT test. In the event that you outfit your CPT rig with an electronic wave generator, gathering seismic information is as basic as squeezing a catch.