Effect of the amplification factor on seismic stability of expanded municipal solid waste landfills using the pseudo-dynamic method

The evaluation of the seismic stability of an expanded municipal solid waste (MSW) landfill is very important in seismic prone zones. In this paper, the pseudo-dynamic method was used to calculate the average safety factor for the expanded landfill with a trapezoidal berm based on under-berm failure conditions. Furthermore, the effects of the variation of parameters such as the amplification factor, seismic coefficient, height of berm, angle of back slope of berm, and depth of waste mass at the back slope on the seismic stability of the landfill were studied. The results indicated that the influences of the vertical seismic coefficient, height of berm, and angle of the back slope of the berm on the seismic stability of the landfill are weakened as the amplification factor increases, but the influence of the horizontal seismic coefficient on the seismic stability of the landfill is strengthened. On the other hand, a certain ratio of the height of the waste mass above the back slope to the depth of waste mass at the back slope, or the reasonable consideration of the magnitude of the amplification factor will be conducive to the seismic design of the landfill. In addition, the results obtained by the pseudo-static and pseudo-dynamic methods were compared.