The soil improvement method by which the granular soil is compressed is with the use of electrical or hydraulic vibrolance, known as vibroflotation.
One of the objectives of this method is:
Increase load capacity of the ground, through particle densification by the possibility of changing from deep foundations to superficial foundations.
Before undertaking vibroflotation jobs, it is necessary to perform SPT tests for reviewing, among other things, the initial soil resistance, as well as the content of fines; making it possible to determine the most adequate spacing between points (grid) for the execution of the improvement.
After the improvement, a second phase of SPT tests are performed at the same site where the prior soundings were made, in order to verify the results of the vibroflotation.