Abstract:

Adding gravelly soil around the shallowburied metro station has some positive effect on decreasing the uplift of the structure, but the method still can be improved. The antiuplift effect of tunnel structure by original design, that by Ushaped gravelly soil and that by improved gravelly soil are compared and analyzed by an elementfinite difference coupling method. The results show that the antiuplift effect of improved gravelly soil is better than that of Ushaped gravelly soil; more severe acceleration response of the structure would be induced the by improved gravelly soil; the antiuplifting mechanism of improved gravelly soil is restraining the accumulation of excess pore water pressure of soil and restricting flow deformation of liquefied soil around the metro station to reduce the uplift displacement of the structure; the performance of uplift control varies with different earthquake density.

Key words: metro station structure, earthquake, liquefactioninduced uplift, gravelly soil, numerical simulation