<p>In coral reef hydraulic reclamation projects, coral sand and silt interbedded foundations are established within the reefs because of particle sorting. The seismic response of a coral sand and silt interbedded foundation was investigated using a 1-g shaking table test and compared to that of a pure coral sand foundation. Research indicated that during seismic activity, the overall stiffness of coral sand and silt interbedded foundations surpassed that of pure coral sand foundations. When comparing a pure coral sand foundation to a coral sand and silt interbedded foundation, the latter modifies the distribution of excess pore water pressure. Notably, the depth–distribution curve of excess pore water pressure directly beneath the superstructure takes on a “Z” shape. This significantly reduces the excess pore water pressure in the upper region. When the peak ground acceleration (PGA) is 0.2&#xa0;g, the presence of a coral silt layer significantly reduces both the horizontal displacement and settlement of the superstructure. In fact, the settlement of the superstructure on a coral sand and silt interbedded foundation is reduced by nearly 78.3% compared to a foundation composed entirely of coral sand. The shear strain in both pure coral sand foundations and coral sand and silt interbedded foundations decreases with depth, highlighting the influence of overburden pressure.</p>