Development of Bidirectional Tilt Table for Testing of Interface Shear Strength Property

Abstract

The interface shear strength is an important parameter that is always used in the design of most of the geotechnical structures. Nowadays, many geotechnical engineers usually use the approximate values instead of the real value obtained from a relevant test. This leads to inconsistencies between the calculated value and real field value. This research aims to study and develop a tilt table for determining bidirectional interface shear strength for the low normal stress condition between sand and structural surfaces, which are mortar, plywood, and non-woven geotextile. Then, the coefficients of friction were compared with the values obtained for the high normal stress condition, which were obtained by the interface direct shear tests. The results from the tilt table tests shows that failure envelopes were circular, with the radius increases with increasing normal stress. However, it was found that the coefficients of friction from the interface direct shear test are significantly higher than the ones from the tilt table test.