Shaking table investigation of effects of inclination angle on seismic performance of micropiles

This paper aims to experimentally study the performance of inclined micropiles under dynamic loading conditions. Analysis is performed using data obtained from shaking table tests on a small-scale physical model of micropiles with different inclination angles. The physical model includes a 4×4 micropile system inserted in sandy soil with low relative density. Inclination angle of micropiles in the direction of shaking is varied in the range of field applications. A sine wave is applied to the physical model as the input excitation and acceleration response at different points of the physical model are recorded and analyzed to investigate the effects of inclination angle of micropiles on their seismic performance. After describing the small-scale physical model used in this study, results of shaking table tests are presented, and effects of inclination angle on the dynamic response of the soil-micropile system are examined. Results of this study indicate that inclined micropiles exhibit a better seismic performance than vertical micropiles. Dynamic amplifications of acceleration on micropiles and soil surface can be reduced by inclining the micropiles.