Influence of sampler type on torque measurements in SPT-T test

• Grant number: 06/06773-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2007
• End date: October 31, 2007
• Field of knowledge: Engineering - Civil Engineering - Geotechnical Engineering
• Principal Investigator: Anna Silvia Palcheco Peixoto
• Grantee: Renato Kimura Montanha
• Host Institution: Faculdade de Engenharia (FE). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil

Abstract

In Brazilian foundation practice, SPT Test is generally used in the design of pile and shallow foundations. By the way, Mayne (2001) inquire how just a number (N-value) is enough to estimate a great number of different soil parameters and advocated the use of in situ testing with hybrid devices. Ranzini (1988) just already suggested supplementing the conventional SPT with measurement of the torque required to turn the split spoon after driving. After this, some consultants began to use that new technique. Peixoto (2001), in her Ph.D. Thesis "The SPT-T Test and his Application in Foundation Engineering”, studied several aspects of that test: the behavior of the torque versus rotation degree shape; the T/N ratio; the speed test and a suggestion of a method to predict the bearing capacity of piles. However a time is necessary to study the influence of the type of amostrador in the measure of the torque that NBR 6484 (2001) defines as amostrador standard type Raymond, however longitudinally presents the possibility of the body to be, or not, bipartite. In this manner, this research has intention to verify the efficiency of the torque in function of the type of amostrador. Some researchers inquire about the split spoon lead a increasing of the torsion to broken the adhesion between sampler and soil. In this manner, this research intends verify the efficiency of sampler type in the torque measurements in SPT-T test.