Development and Field Verification of Torsional Cylindrical Impulse Shear Test
[ NCHRP 20-30 (NCHRP-IDEA) ]
Project Data
Staff Responsibility:
Dr. Inam Jawed
This project developed and tested an in-situ torsional cylindrical impulse shear test for shearing deformation characteristics for geotechnical earthquake engineering analysis applications (Figure 1). The work involved rebuilding and improving an existing FHWA’s impulse shear testing system. All main components of the FHWA probe were assembled or reassembled and bench tested. These components included the testing module, the hydraulic module (containing a new sensing system for measuring the advance of the probe cylinder into the test soil), and a newly devised axial load cell. The bench tests indicated satisfactory performance of all the components and equipment. The components of the accessory equipment were also repaired, reassembled and bench tested. These components included a manually operated simple probe bed, a hydraulic pump, an electric generator, and a hydraulic system control panel. Bench tests indicated satisfactory performance of each of the components. Work is now under way on the consolidation of the data acquisition and control systems. This IDEA project is being complemented by a FHWA/State DOT-sponsored pooled-fund study for further development and implementation of the impulse shear test. The final report is available from the National Technical Information Service (NTIS # PB2004-100132).
