Sustainable rural infrastructure: guidelines for roadside slope excavation

Abstract

The construction of non-engineered, equipment-based rural roads in Nepal Himalaya is one of the predominant causes of landslides. The construction frequency of such roads has significantly increased over the past decade. However, the present guidelines governing slope excavation for these roads are not based on geotechnical characterizations of sites. The current study uses the limit equilibrium method with the Mohr–Coulomb constitutive model to determine safe cut heights and slopes for varying geometric and material parameters. GeoStudio Slope/W was used to model soil slopes with various gradients, and cuts with varying depths and slope angles were modeled to calculate the factor of safety (FoS) against shear failure for different geometric and material conditions. The results of the study were visualized in design charts with FoS as the dependent variable. The analysis highlights the importance of different parameters, i.e., excavation depth, excavation slope, and existing ground slope in the FoS, in addition to the slope-forming material. Furthermore, a field study was carried out to validate the model using the clustering approach. The results from the field are similar to those from the numerical model, although some additional site-specific parameters like vegetation cover and surface runoff conditions should be considered before selecting the cut slope. Finally, this study proposes that future road construction guidelines should consider terrain parameters, hydrology, and geotechnical site conditions to promote sustainable road infrastructure and reduce future disaster risks in the Himalayan region.

Enhancing co-seismic landslide susceptibility, building exposure, and risk analysis through machine learning

“…The stability of slopes is directly affected by anthropogenic factors such as road excavations 59 . Due to unplanned and nonengineered road construction, the mountainous regions of Nepal have experienced many landslides 7 .…”

Finite Element Analysis on Load-Settlement Behavior of Axially Loaded Pile on Sand

“…Over the past few decades, extensive research has been conducted to explore the characteristics of sands and clays (Dahal et al, 2018). Various scholars have delved into this subject and contributed to the field by presenting formulas, charts, and tables as valuable resources to aid in the design of geotechnical structures (Dahal et al, 2019;Paudyal et al, 2023). The parameters commonly studied in this context include mechanical attributes for sand, such as φ, E, ν, and ψ (Degago et al, 2010).…”

A participatory approach to determine the use of road cut slope design guidelines in Nepal to lessen landslides

“…Road cut slope failures are widespread throughout the road network in Nepal (see examples of such cut slope failures in Figure 1) due to a combination natural and anthropogenic causes (McAdoo et al, 2018;Robson et al, 2024). Paudyal et al (2023); Robson et al (2022Robson et al ( , 2024 suggest that the extensive cut slope failures on the Nepal road network can be partly blamed on the limitations of current guidelines used by engineers to design the cut slopes in Nepal. In this paper, we present the methods and outcomes of a These environmental and physiographic features result in Nepal having an extremely dynamic landscape, and constructing a fixed linear structure of a road on this dynamic landscape is hugely challenging.…”

“…They outlined that these guidelines often do not account for important geotechnical characteristics, can lack suitable descriptions, are often generic, and are often presented in inaccessible formats. Paudyal et al (2023) also highlighted limitations in the current Nepali guidelines, suggesting that the geomaterial classifications are too broad leading to mischaracterization of geomaterials and, consequently, the design of unsafe cut slopes. Paudyal et al (2023); Robson et al (2022) both call for the redesign of road cut slope guidelines for Nepal.…”