Physical Models to Investigate Soil Arching Phenomena Under Cyclic Footing Loading Using Transparent Soil

Abstract

Soil arching is one of the most universal phenomena in the geotechnical engineering practices, such as embankment, tunneling, piping, and retaining wall. In the past decades, most studies mainly focused on soil arching under static loading. However, some numerical studies and field tests show that soil arching more likely degrades to failure under cyclic loading than under static loading. In this study, a series of two dimensional (2-D) trapdoor tests with transparent soil were carried out to investigate the soil arching phenomena under cyclic footing loading. The test setup included a container with inside dimensions of 90 cm (length) × 10 cm (width) × 50 cm (height) and three trapdoors with 20 cm in length installed on the base of the container. A cyclic surface footing load was applied at the center of the transparent soil. The Particle Image Velocimetry (PIV) technique was adopted to investigate the deformation field in the transparent soil. Three influence factors (fill height, load frequency, and geosynthetic reinforcement) on the soil arching phenomena under cyclic footing load were explored. The test results showed that the increase of cyclic load frequency accelerated soil arch failure. The inclusion of geosynthetic reinforcement enhanced the stability of soil arching under a cyclic footing load. The existence of soil arching redistributed displacements in the fill. After the soil arching was destroyed under the footing load, the displacements in the fill spread out in a similar manner with that in the model test without trapdoor movement.