Study on seismic isolation measures for cross-fault embankment

Under the movement of fault, embankment can produce uneven displacement, deformation and even destruction. Consequently, it is necessary to adopt appropriate seismic measures to reduce the deformation or damage of embankment with the fault displacement. In view of this, the dynamic response of a cross-fault embankment with raft foundation as a seismic isolation measure was simulated by ABAQUS in this paper. Based on the reverse fault and normal fault, three kinds of setting positions of the raft foundation were set and then the displacement of subgrade surface and bending moments of raft foundation in all kinds of working conditions were calculated and compared. The results show that when s/b = 0.75, the fracture zone is shifted to the right compared with no foundation, indirectly reducing the dip angle of fault (“s” is the distance that from left endpoint of the foundation to the surface outer point of fault without foundation, “b” is the width of foundation). In addition, it is found that the vertical displacement curve of subgrade surface when s/b = 0.75 is gentler than other working conditions, furthermore, the curve’s largest inclination value and bending moment of raft foundation are the minimum. Therefore, the best condition for raft foundation as a seismic measure to cross-fault embankment is s/b = 0.75.