Sensibility Analysis of the Hydraulic Conductivity Anisotropy on Seepage and Stability of Sandy and Clayey Slope

Abstract

Evaluation of slope stability under rainfall is an important topic of Geotechnical Engineering. In order to study the influence of anisotropy ratio (kr = kx/ky) and anisotropy direction (α) on the seepage and stability of a slope, the SEEP/W and SLOPE/W modules in Geo-studio were utilized to carry out the numerical analysis of a homogeneous slope in Luogang District, Guangzhou City, China, which is based on the theory of unsaturated seepage and stability. Two kinds of soils (clay and sand) were included. Results show that: For sandy soil slope, the increase of kr promotes the rainfall infiltration, and the decrease of α prevents the rainfall infiltration. The maximum water content of the surface (MWCS) reaches maximum with the increase of kr and α. The rising height of groundwater (RHG) is −3–4 m and the safety factor (SF) is 1.3–1.7. For clayey soil slope, variations of kr and α have little impact on the seepage characteristics and slope stability. The MWCS remains almost the same. The rainfall infiltration depth (RID) is 0.5–1 m and the SF is about 1.7. Therefore, for sandy soil slope, it is not only necessary to consider the influence of kr, but also the influence of α. For clayey soil slope, it can be treated as isotropic material to simplify calculation.

Deformation and Stability Characteristics of Layered Rock Slope Affected by Rainfall Based on Anisotropy of Strength and Hydraulic Conductivity

“…The HDs at the bottom and middle of the slope were larger than the top of the slope. According to previous studies [3,9,30], the hydrodynamic pressure generated by rainfall had a large impact on the bottom and middle parts of the slope, and the landslide between the bottom and middle of the slope, which verified the results of the numerical simulation. Generally speaking, the hydraulic conductivity and strength anisotropy characteristics also had great impacts on the variation of HD.…”

“…To simulate the seepage processes of rock slopes, rainfall infiltration was regarded as the variable flow boundary of the unsaturated zone, and a saturated-unsaturated seepage theory was applied to perform the simulations. Under the principle of mass conservation, the saturated-unsaturated seepage control differential equation is as follows [3,9,30]:…”

“…During the period of heavy rainfall (from 21 June to 26 July 2019), the overall FSs obviously decreased and the FS of the rock slope decreased with the increase of β. Xia et al [9] conducted relevant simulations and the results were similar to current research results. This is because a larger dip angle of the bedding plane would lead to a smaller hydraulic conductivity in the horizontal direction and a larger hydraulic conductivity in the vertical direction, which would promote the rainwater infiltrating into the deep part of the slope body [3,9,30], increase the height of the groundwater level and pore water pressure, and finally reduce the effective stress and shear strength. When the rainfall was heavy and the rainfall time was short, the FS increased sharply.…”

Structural mitigation measures for flood reduction in urban area: A case study of Ciliwung watershed

“…SLOPE/W can be analyzed both simple and complex problems using one of eight boundary equilibrium methods for various sloped surfaces, compressive conditions of water pores, soil properties and concentrated loads. The program is also widely used to simulate stability [7][8][9][10].…”

Keefektifan Penambahan Kapasitas Saluran dan Dinding Penahan Tanah pada Sungai Brantas Hulu di Kediri dalam Mitigasi Banjir

“…Analisis selanjutnya adalah penilaian faktor keamanan lereng pada saluran yang akan dilakukan menggunakan bantuan perangkat lunak Geo-Studio pada fitur SLOPE/W. Fitur ini dipilih berdasarkan kajian yang telah dilakukan oleh banyak penelitian (Shole and Belayneh, 2019;Yu et al, 2020). Tabel 8 menunjukkan hasil simulasi faktor keamanan yang terjadi pada lereng.…”