Study on numerical simulation analysis methods of multi-layer discontinuous rammed earth structure

Abstract

The structure of rammed earthen sites is affected by the ramming process, forming a discontinuous layered structure with a fragile layer interface. The weak bond tensile strength of the layer interface seriously restricts the overall stability of the rammed earth. However, due to their cultural heritage status and unique construction methodology, direct on-site monitoring of their structural integrity is often infeasible. Finite element analysis emerges as a pivotal tool for simulating diverse operational scenarios, where developing appropriate modeling methodologies remains a critical challenge. Usually, the continuous homogeneous model is often used in the stability analysis of rammed earth, and the conclusion deviates from reality. Based on ANSYS simulation, this paper constructs a continuous homogeneous, layered continuous, layered discontinuous, multi-layer discontinuous layer interface weakening rammed earth structure. Based on the spectrum test results of full-scale shaking table in-situ wall and undercutting wall simulation experiments, the main factors affecting the construction of a multi-layer discontinuous rammed earth structure model are revealed. The weakening of the weak layer of the layer interface should be considered in the rammed earth structure, which is closer to the actual situation. Layer interface weakening (material properties), thickness, number and arrangement of elements, and elastic modulus are the main influencing factors. In the model, the three-dimensional proportional relationship of the weakened layer interface does not exceed 20, and the discontinuous structural layer units are arranged one by one. The thickness of the weak layer should be moderate to ensure the accuracy of the model.