scholarly journals Stability Analysis of Plant-Root-Reinforced Shallow Slopes along Mountainous Road Corridors Based on Numerical Modeling

Geosciences ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 19 ◽  
Author(s):  
Damtew Tsige ◽  
Sanjaya Senadheera ◽  
Ayalew Talema

Engineering methods such as soil nails, geosynthetic reinforcement, retaining structures, gabions, and shotcrete are implemented to stabilize road cut slopes along mountainous areas. However, these structures are not environmentally friendly and, particularly in Ethiopia, it is impossible to address all road problems due to financial limitations. Nowadays, soil reinforcement with plant roots is recognized as an environmentally sustainable alternative to improve shallow slope failure along mountainous transportation corridors. The aims of this study was, therefore, to conduct slope stability analysis along a road corridor by incorporating the effect of plant roots. Five plant species were selected for the analysis based on their mechanical characteristics. Namely, Eucalyptus globules (tree), Psidium guajava (shrub), Salix subserrata (shrub), Chrysopogon zizanioides, and Pennisetum macrourum (grasses). The roots’ tensile strength and soil parameters were determined through tensile strength testing and triaxial compression tests, respectively. The factor of safety of the slope was calculated by the PLAXIS-2D software. The study showed that when the slope was reinforced with plant roots, the factor of safety (FOS) improved from 22–34%. The decreasing effect of vegetation on slope stability was observed when soil moisture increased. The sensitivity analysis also indicated that: (1) as the spacing between plants decreased, the effect of vegetation on the slope increased. (2) Slope angle modification with a combination of plant roots had a significant impact on slope stabilization. Of the five-selected plant species, Salix subserrata was the promising plant species for slope stabilization as it exhibited better root mechanical properties among selected plant species.

2018 ◽  
Author(s):  
Darmadi Ir

Abstract Slope stability analysis with SOFTWARE ROCSCIENCE SLIDE case studies in residential barracks of PT. Freport with various variations in loading and conditions show results The greater the load on the slope, the lower the Factor of Safety value. FS values for all methods, sections, and ramp widths are greater in dry than wet conditions. The greater the load distance from the slope, the greater the FS value. At a distance of 3m from the crest slope the decrease in FS value is very significant, in sections 1 and 2 there is still a secure FS value with a load of 50 kN / m, the smaller the overall slope angle (slope) the greater the FS value.Keywords: Slope stability, safety factor, maximum load


2021 ◽  
Vol 11 (10) ◽  
pp. 4568
Author(s):  
Muhammad Israr Khan ◽  
Shuhong Wang

Assessment and analysis of soil slope stability is an important part of geotechnical engineering at all times. This paper examines the assessment of soil slope stability in fine-grained soils. The effect of change in shear strength (τ), shear stress (σ) and slope angle (β) on the factor of safety has been studied. It correlates shear strength with slope angle and shear stress by considering the horizontal seismic coefficients in both saturated and unsaturated conditions. The slope failure surface was considered a circular slip surface. Statistical package for social sciences (SPSS) and Slide, numerical modeling software and limit equilibrium slope stability analysis software, respectively, are used to find out the correlations between the three basic parameters. The slope angle varied from 70 to 88 degrees, which are the most critical values for slope angles, and a total of 200 analyses were performed. τ, β and σ are correlated, and the correlations are provided in the results section. The results indicate that the correlations developed between the parameters have a very close relationship. The applicability of the developed equations is above 99%. These correlations are applicable in any type of soil slope stability analysis, where the value of shear strength and factor of safety is required with the variation of slope angle and shear stress.


2021 ◽  
Vol 15 (2) ◽  
pp. 35-46
Author(s):  
Yamah Joy Barvor ◽  
Sher Bacha ◽  
Cai Qingxiang ◽  
Chen Shu Zhao ◽  
Nisar Mohammad ◽  
...  

Purpose. To analyze the coupling effect between composite slope geometrical parameters. Methods. The slope angle and excavation depth are coupled with load which is waste dump in this case. Several models were created and analyzed to capture their coupling effect and interactions using FLAC/Slope. Findings. When the slope angle and excavation depth are coupled with a load such as that of a waste dump, the factor of safety decreases. But a suitable dumping position can prove vital to enhancing stability. The primary cause of this phenomenon is that the stresses induced by the waste dump decrease as the dump is moved away from the crest of the slope and the stress induced within the zone of active wedge beneath the dump reduces on the reference slip plane. Hence, it can be said that the position of the waste dump in the formation of a composite slope plays a key role in enhancing stability. Factor of safety have the same influence pattern for all parameters induced by stress as that of influence rule. The results obtained from the finite element stress analysis are the same with those obtained for the slope stability analysis. Originality. The current research presents for the first time the coupling effect of the composite slope geometrical parameters and the results of finite element stress analysis, which are similar to those of slope stability analysis. Practical implications. The current research results can be used to effectively analyze and design the composite slopes in soft rocks specially in surface mines.


2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Ashok Sigdel ◽  
Radha Krishna Adhikari

Detailed investigation of Taprang landslide was carried out in order to understand the surface, subsurface lithological information and physical properties of soil by using multi-disciplinary methods such as engineering geological, geophysical and geotechnical studies for the determination of factor of safety for slope stability analysis.  Geological study was carried out by detail mapping of surface geology, soil condition, properties of bedrock and its discontinuities. The geophysical survey (Electrical Resistivity Tomography-ERT) were carried out to know the electrical resistivity of soil for identifying the groundwater table and hence slip surface of the landslide. Geotechnical analysis such as grain size analysis, liquid limit and direct shear test were carried out in order to evaluate soil classification, moisture content, cohesion and the angle of internal friction of soil for knowing the strength the soil. These soil parameters indicate the soil is very low strength. The combination of these results were used for calculating the factor of safety (FoS) by Limit Equilibrium Method (LEM) proposed by Bishop and Janbu methods. The result of factor of safety in the Taprang landslide demonstrates that the slope become stable in drained (dry) condition, remain ultimate stage in undrained (wet) condition and finally failure occurs if applied the seismic load in both drained and undrained conditions.


2021 ◽  
pp. 46-54
Author(s):  
Muhammad Amin Syam ◽  
Heriyanto Heriyanto ◽  
Hamzah Umar

PT Belayan Internasional Coal is an open-pit system mining company, one of its geotechnical activities is the construction of the slopes. Slope stability analysis used the Bishop Simplified method to obtain the value of the dynamic safety factor (≥ 1,1). Currently, the value of the Safety Factor (FK) is an indicator in determining whether the slope is stable or not. The parameters used in the slope stability analysis are the physical and mechanical properties of the rock, namely weight (ɣ), cohesion value (c), and internal shear angle (∅). From the results of dynamic overall slope calculations, the recommended overall slope is constructed with an individual slope angle of 55°, a bench width of 5 meters, a height of 10 meters, and the number of individual slopes of 8 slopes. This design will produce dimensions of the overall slope with 41° slope angle, 80 meters high, and has a dynamic safety factor value of 1,102 with the water-saturated condition. Thus, the slopes are in stable condition.


1994 ◽  
Vol 31 (6) ◽  
pp. 1015-1021 ◽  
Author(s):  
Azm S. Al-Homoud ◽  
Ahmad B. Tal ◽  
Abdallah I. Husein (Malkawi)

This paper includes a summary of a geotechnical investigation of an embankment site at station 47 + 300 along the Irbid–Amman Highway in Jordan. The embankment suffered instability problems. This study includes geological and geotechnical mapping of the study area as well as determination of the engineering properties of the various materials encountered at the site.Stability analysis is carried out for the original embankment to explain the failure mechanism, assess the condition at the time of failure, and evaluate the soil parameters for use in stability analysis of remedial measures. Stability analysis is carried out for remedial works. Recommendations are suggested to stabilize the sliding area and to repair the road traversing this landslide zone. Key words : slope stability, embankment, remediation.


Author(s):  
Agnieszka Dradrach ◽  
Anna Karczewska ◽  
Katarzyna Szopka ◽  
Karolina Lewińska

The uptake of As by various plants growing in highly enriched sites was examined in order to identify potential As accumulators and to assess the risk associated with As presence in plant shoots. Representative samples of 13 plant species, together with soil samples, were collected from various sites affected by historical As mining: mine and slag dumps, tailings and contaminated soils with As concentrations in a range 72–193,000 mg/kg. Potentially and actually soluble As forms, extracted with 0.43 M HNO3 and, 1M NH4NO3 were examined in relation to As concentrations in plant roots and shoots. The latter differed strongly among the species and within them and were in the ranges 2.3–9400 mg/kg and 0.5–509 mg/kg, respectively. The majority (over 66%) of plant samples had As shoot concentrations above 4 mg/kg, an upper safe limit for animal fodder. The uptake of As by plants correlated well with total and extractable soil As, though As concentrations in plants could not be predicted based on soil parameters. Equisetum spp. and C. epigejos indicated a particularly strong accumulation of As in shoots, while A. capillaris, and H. lanatus showed a limited As root-to-shoot transfer, apparently associated with species-related tolerance to As.


2020 ◽  
Vol 841 ◽  
pp. 155-160
Author(s):  
Pongsakorn Wongchana ◽  
Peerapong Jitsangiam

The open pit mine is excavation soil from the Earth's surface, leading to presence of cut steep slopes with stability-concerned manners. Mae Moh open pit mine has the main component of claystone with ambiguous properties under stress condition changes from mine operations. Therefore, the strength of the claystone must be studied to be used for the slope stability analysis. Shear strength parameters for slope stability analysis were derived from the Triaxial Compression tests. Claystone is a type of sedimentary rock. Therefore, it is necessary to improve the equipment of the triaxial compression strength test to fit with intrinsic soft rock characteristics of the Mae Moh Claystone. Determination of parameters was based on Mohr Coulomb model, because it is the basis for slope stability analysis and can be resulted from the triaxial compression test. In addition, many computer-based programs for slope stability analysis also were relied onthe Mohr Coulomb model, including PLAXIS used in this study. Before the analysis, the model were validated by the function of “Simulation of Lab Test” in PLAXIS. Comparison on triaxial compression test results between the Mohr-Coulomb Model from PLAXIS and triaxial compression tests were made. This article reported the strength characteristics of Mae Moh claystone.


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