Model tests of reinforced soil retaining sand walls by shaking table test

Abstract

This research investigates the seismic response of sand-made wrap-faced retaining walls using a shaking table, focusing on the impact of varying relative densities and frequencies on the dynamic characteristics of the walls. Two types of sand have been used to prepare retaining wall model for shake table testing. They are “Local” sand and “Sylhet” sand. A 2 m × 2 m computer-controlled servo-hydraulic single degree of freedom shaking table facility in geotechnical laboratory of Bangladesh University of Engineering and Technology (BUET) has been used to test the model under sinusoidal loading. Here, different kinds of combination of seismic waves of different frequencies are selected to apply on different densities wrap-faced wall model in order to observe their dynamic characteristics. The relative densities of Sylhet sand are chosen 48%, 64%, and 80% for preparing the model wall. On the other hand, 48%, 64%, and 80% are selected for preparing Local sand model. Portable traveling pluviator (PTP) developed by (Hossain and Ansary, Innov Infrastruct Solut 3:53, 2018) has been used here to construct the uniform wrap-faced retaining wall model. Tests are performed under three different surcharge pressures like 0.7 kPa, 1.12 kPa, and 1.72 kPa. Sinusoidal tests are implemented for three base accelerations (0.1 g, 0.15 g, and 0.2 g) and for eight different frequencies (1 Hz, 2 Hz, 3 Hz, 5 Hz, 8 Hz, 10 Hz, 12 Hz, and 15 Hz). In the end, from these test results, it has been observed that acceleration amplification is inversely proportional to relative density. Further, acceleration amplifications are increased with the rise of frequencies. On the other hand, face displacement has been decreased with the increase of the relative density and frequency at same normalized elevation. The test results have been compared with (Krishna and Latha, Geosynth Int 14:355–364, 2007), although they used poorly graded sand and different scaling factor of the retaining wall model. It has been also noticed that the Sylhet sand retaining wall shows more acceleration amplification during sinusoidal loading than the Local sand retaining wall. In this research, the impact of different kinds of relative densities and frequencies on wrap-faced retaining wall model under sinusoidal testing has been observed.