This paper is focused on the influence of foundation soil on the seismic factor of the safety of a typical side-hill type solid-waste landfill. New analytical expressions are derived and presented to calculate the displacement, shear strain, and seismic accelerations within the landfill body and in the foundation soil. A new equivalent-linear-based approach is proposed to compute the seismic factor of the safety (FSavg) of municipal solid waste (MSW) landfills considering the effect of the foundation type. In the present study, four different foundation types are considered: shallow sand deposit (foundation type I), deep sand deposit (foundation type II), shallow clay deposit (foundation type III), and deep clay deposit (foundation type IV). Moreover, the proposed method considered the strain-dependent equivalent-linear material parameters (secant shear modulus and damping ratio) rather than a small-strain shear modulus and a fixed damping ratio. The acceleration ratios (ratio of surface to bedrock accelerations) obtained from the proposed method are in good agreement with the DEEPSOIL version 6.1 equivalent-linear results. The maximum shear strain within the landfill body significantly decreases with an increase in the input excitation frequency from 0.2 to 3 Hz. In addition, the landfill enters higher vibration modes. At higher vibration modes, a portion of the seismic acceleration acts in one direction, and the remaining portion acts in the opposite direction. This phenomenon reduces the net amount of acceleration acting on the landfill body that, in turn, results in a higher safety factor. The seismic factor of the safety values computed from the present equivalent-linear analysis is compared with the results of the present linear and pseudodynamic analyses. The parametric study revealed that the critical and safe foundation type for the seismic stability of MSW landfills also changes with a change in the input motion frequency. For an input frequency of 3.0 Hz, foundation type I is identified as the most critical one with the lowest FSavg, and foundation type IV is the safest one with the highest FSavg. Similarly, for an input frequency of 1.75 Hz, foundation type II is identified as the most critical foundation with the lowest FSavg, and foundation type III is on the safest side with the highest FSavg.

中文翻译：

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地基土对衬砌合成固体垃圾填埋场安全性的地震影响：等效线性法

本文着眼于地基土对典型边坡固体垃圾填埋场安全性的地震因素的影响。推导并提出了新的解析表达式，以计算垃圾填埋场主体和基础土壤中的位移，剪切应变和地震加速度。提出了一种基于等效线性的新方法，考虑了地基类型的影响，计算了城市生活垃圾（MSW）垃圾填埋场的安全性（FSavg）。在本研究中，考虑了四种不同的地基类型：浅砂沉积物（基础类型I），深砂沉积物（基础类型II），浅粘土沉积物（基础类型III）和深粘土沉积物（基础类型IV）。此外，该方法考虑了应变相关的等效线性材料参数（割线剪切模量和阻尼比），而不是小应变剪切模量和固定的阻尼比。通过该方法获得的加速度比（地表加速度与基岩加速度之比）与DEEPSOIL 6.1版的等效线性结果非常吻合。填埋体内的最大剪切应变随着输入激励频率从0.2到3 Hz的增加而显着降低。此外，垃圾填埋场进入了更高的振动模式。在较高的振动模式下，地震加速度的一部分沿一个方向作用，其余部分沿相反的方向作用。这种现象减少了作用在垃圾填埋场上的净加速度，从而导致更高的安全系数。将根据当前等效线性分析计算出的安全值的地震系数与当前线性和拟动力分析的结果进行比较。参数研究表明，MSW垃圾填埋场地震稳定性的关键和安全基础类型也会随着输入运动频率的变化而变化。对于3.0 Hz的输入频率，基础类型I被确定为FSavg最低的最关键的基础，基础类型IV被确定为FSavg最高的最安全的基础。同样，对于1.75 Hz的输入频率，基础类型II被确定为FSavg最低的最关键基础，基础类型III在FSavg最高的最安全的一面。