Effects of frame beam on structural characteristics of artificial soil on railway cut‐slopes in southwestern China

Abstract

Cut-slope restoration technologies commonly used in southwest China mainly include using simple outside soil spray seeding (OSSS) techniques, or OSSS combined with an anchor frame beam. Artificial soil used in OSSS can establish a soil layer suitable for revegetation; the addition of an anchor frame beam not only fixes soil and shallow rock, it also acts to strengthen deep rock. However, there have been few studies on the effects of frame beams on artificial soil structural characteristics on railway cutslopes. In order to evaluate the effects of different frame beams on artificial soil structure, soil samples from a natural slope (NS) and three cut-slopes restored using OSSS with various frame beams (AS, arched slope; DS, diamond slope; and RS, rimless slope) were analyzed. Soil structural characteristics analyzed include particle-size percentage and cumulative distribution curve of dry-sieving and wet-sieving aggregates, structural failure rate, water stability factor, soil particle size distribution (PSD), bias and peak convex coefficients, fractal dimension of PSD (D m ), and fundamental properties. Our results indicate that structural failure rate, water stability factor, fractal dimension of PSD, soil bulk density, total porosity, moisture content, and organic matter are significantly affected by the use of different frame beams. In addition, a difference in wetsieving soil aggregates content, PSD, clay and sand particle contents, D m, and the area difference ΔS of cumulative distribution between AS and DS was evident. Overall, soil structure in cut-slopes using a diamond frame anchor beam recorded the best levels of recovery after 8 years of ecological restoration.

The formation of small macro‐aggregates induces soil organic carbon stocks in the restoration process used on cut slopes in alpine regions of China

“…On the other hand, the soil porosity in CSN and CST was higher than that in CSG. High porosity reduced soil aggregate stability against hydraulic erosion and mechanical stress (Ai, Sheng, et al, 2021; Ai, Wang, et al, 2021). Random Forest model analysis found that large macro‐aggregates was the largest contributing factor to soil aggregate stability (Figure S3), and the stability increased with the increase of the mass proportion of large macro‐aggregates, which was consistent with the previous research results (Abiven et al, 2009; Li, Wang, et al, 2021; Li, Li, et al, 2021).…”

“…Soil spray seeding has been widely used in these areas because of its strong adaptability and rapid effect (Jiang et al, 2021). This process generally consists of laying soil consolidation mesh on a cut slope, then fixing it with anchor bolts and rivets, and finally spraying artificial soil on it with special sprayers (Ai, Sheng, et al, 2021). The aforementioned artificial soil is usually a mixture of clay loam, humus, soluble fertilizer, water retaining agent, binder, and plant seeds in a certain proportions (Fu et al, 2018; Li, Zhang, et al, 2018).…”

A Comparison of Load Distribution Methods at the Node and Internal Force Analysis of the Lattice Beam Based on the Winkler Foundation Model

“…In China, the lattice beam placed on the slope surface is a reinforced concrete frame beam structure, which is mainly made of concrete with a compressive strength of not less than 25 MPa (C25), the crosssectional area of the beams is not less than b × h = 250 mm × 300 mm, and the distance between the adjacent beams in both directions should be less than 4.0 m [10]. Since the successful application of lattice beams in highway slopes in the 1980s in China, the lattice beam slope anchorage system has been widely used for the reinforcement of various high and steep man-made slopes [11][12][13] or landslides [14,15] due to its light weight, flexibility, and good seismic performance [16][17][18][19][20]. Similar to the design of the traditional slope retaining structure, in addition to obtaining the parameters such as displacement, stress, strain, and FOS of the slope by numerical analysis [21][22][23], the design of the lattice beam slope anchorage system requires accurate calculation of the internal forces such as bending moment and shear force of the lattice beam.…”

Illuminating Plant Community Assembly on Karst Mountain Road Slopes through Plant Traits and Environmental Filters

“…However, restoring these slopes has long posed a challenge for ecological rehabilitation practitioners. Despite various innovative engineering techniques for restoration [4][5][6][7], these methods often lead to unnatural and unsustainable post-recovery vegetation [2]. A more effective approach lies in understanding spontaneous processes like diffusion, colonization, and succession, pivotal for rehabilitating disrupted sites [8][9][10][11].…”