A cut slope in Rajamandala, Indonesia exhibited unexpected large-scale deformation during the excavation process which was revealed by the clinometers attached to the preventive piles. A geological survey indicated that the mudstone layer composing the slope had been folded by tectonic movement and was highly weathered and eroded at the surface. The above internal factors could have resulted in the significant deformation of the slope, although few studies have focused on the influence of folded structures and horizontal in-situ stress on the deformation behavior of cut slopes. Therefore, the objective of this paper is to clarify the influence of the folded structure and anisotropic in-situ stress state induced by tectonic movement on the deformation behavior of the aforementioned cut slope. To achieve this clarification, numerical analyses were performed based on the explicit finite difference method included in the FLAC2D software using different geological structures and in-situ stress states. Consequently, it was revealed that such folded structures can lead to larger displacement in cut slopes when compressive stress concentration occurs at the bottom of the fold. Moreover, an anisotropic in-situ stress state can result in shear failure at the foot of the mudstone and reproduce the displacement of piles that possess shapes as close as possible to those observed at the site. These analytical results confirmed that the folded structure and anisotropic in-situ stress state were the inevitable factors in the large deformation of the cut slope in Rajamandala, Indonesia.

印度尼西亚拉贾曼达拉的一个切坡在挖掘过程中出现了意想不到的大规模变形，安装在预防桩上的测斜仪显示了这一情况。地质调查表明，构成斜坡的泥岩层因构造运动而褶皱，地表遭受强烈风化和侵蚀。尽管褶皱结构和水平地应力对路堑边坡变形行为的影响鲜有研究，但上述内部因素可能导致边坡发生显着变形。因此，本文的目的是阐明构造运动引起的褶皱结构和各向异性地应力状态对上述切坡变形行为的影响。为了实现这一澄清，基于FLAC2D软件中包含的显式有限差分法，使用不同的地质结构和地应力状态进行数值分析。结果表明，当压应力集中在褶皱底部时，这种折叠结构会导致切坡产生更大的位移。此外，各向异性的地应力状态会导致泥岩底部发生剪切破坏，并再现桩的位移，其形状尽可能接近现场观察到的形状。这些分析结果证实，褶皱结构和各向异性地应力状态是印度尼西亚拉贾曼达拉路堑边坡大变形的必然因素。