Scaled boundary point interpolation method for seismic soil-tunnel interaction analysis

The scaled boundary method (SBM) is an effective numerical approach for analyzing elasto-statics of bounded and unbounded media. To enhance abilities of the scaled boundary approach, this method can be coupled with mesh free technology. In this paper a point interpolation based SBM is proposed to analyze seismic soil-tunnel interaction problems. In the proposed approach, boundary of the domain is modelled with the scaled boundary point interpolation method while the interior domain is modelled by the conventional finite element method (FEM). This is the first time that a mesh-free scaled boundary method is used to analyze seismic problems. The presented method has some advantages over previously presented mesh-free SBMs. In the scaled boundary point interpolation method, the shape functions have the Kronecker delta function property and do not require radial basis functions to discretize the boundary of 2D problems. A shaking table test is designed and used to verify the proposed method. It is shown that the proposed numerical approach leads to results that are in a good agreement with those of the designed shaking table tests.