كليدواژه :
Baseline , Buried pipelines , Finite difference method , Flac- 2D , Finne Model , liquefaction
چكيده فارسي :
The liquefaction of soils under earthquake loadings has always been a main concern for geotechnical
engineering practices. As an earthquake causes the ground to liquefy, the effective stress and hence the shear
strength of the soil decreases sharply, and large deformations happen in the area. This phenomenon occurs
only rarely when the liquefaction occurs at a large depth. However, deformations increase extensively when
this layer is located in shallow depths near the ground level. In this case super structures and also
underground structures may be severely damaged. Pipelines buried in saturated sand deposits, during
earthquake loading could damage from resulting uplift due to excess pore water pressure generation.
Especially for previously buried pipelines, in order to set the priority for seismic retrofit, evaluating the risk
of floatation in each region could be a concern. In this paper, effects of several parameters including soil
dilatancy angle, soil friction angle, density ratio of natural soil, diameter and burial depth of pipe on uplift of
pipe by construct an advanced soil- pipe model in Flac- 2D software and Finn behavior model under cyclic
loading, have been investigated. Results show the prominent role of friction angle of soil, diameter of pipe
and exist an optimum level for burial depth in pipe response reduced floatation.
