Length rod influence in torque measurement of SPT-T test

• Grant number: 05/02132-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2005
• End date: September 30, 2007
• Field of knowledge: Engineering - Civil Engineering
• Principal Investigator: Anna Silvia Palcheco Peixoto
• Grantee: Valéria Borin Antenor
• 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. But, it is either necessary to study the influence of the length rod in the torque measurement. In this manner, this research pretends verify the efficiency of the torque measurement correlating to the length rod. For this, it will be used the electric torquemeter construct by Peixoto (2001) with a data acquisition system existing in the Civil Engineering Department of FEBA, Unesp, Bauru.