Numerical Analysis of Inclined Micropiles Behavior Under Seismic Load

Performing human made that lead to structures damages have occurred due to earthquakes and seismic load.Studying the existing structures and the methods of retrofitting has an important role in earthquake-pronecountries. Nowadays, micropiles are commonly used in structures as a practical element to retrofit the seismicbehaviors. In this paper, inclined micropiles under the earthquake load were analyzed by finite differencemethod using FLAC 3D. The approach considers an idealization for micro pile-soil system in three dimensionmodel in order to evaluate logically their behaviors when the earthquake occurs. The micropile is assumed tobe linear elastic and the soil is elastoplastic material. The micropile's failure is controlled by the Mohr-Coulomb criterion and all the micropiles were analyzed on the load of earthquake recorded in Tabas, Iran,1978. The results obtained from the numerical analyses were compared with available other data, indicating asatisfactory agreement. The results show that the inclined micropiles, due to being in the soil, give morehardness to it. So these cause less displacement in comparison with vertical ones. Also the micropile-soilinteractions in performance of inclined one were salient.

Keywords:

micropile , inclined micropile , soil improvement , seismic behavior , micropile-soil interaction , finite difference methods