Academia.eduAcademia.edu

Figure 2 – uploaded by Gilang Firmanda

See full PDFdownloadDownload figure
Figure 2. Digital elevation model (DEM) map which show a difference elevation to divide landslide section. From the photogrammetry analysis the authors can separating the landslide in mine waste dump into 3 sections that are crest, body, and toe (Depositional area) of the slope based on elevation difference from the digital elevation model map as shown in Figure 2-3 below. Each landslide section on the slope has a different description, in the crest section of the slope there is an indication of main scrap which reflects the symptoms of circular type landslides on the crest section (Figure 4).

Figure 2 Digital elevation model (DEM) map which show a difference elevation to divide landslide section. From the photogrammetry analysis the authors can separating the landslide in mine waste dump into 3 sections that are crest, body, and toe (Depositional area) of the slope based on elevation difference from the digital elevation model map as shown in Figure 2-3 below. Each landslide section on the slope has a different description, in the crest section of the slope there is an indication of main scrap which reflects the symptoms of circular type landslides on the crest section (Figure 4).

Related Figures (7)

Figure 1. One of the open slope mining on coal mine in Indonesia. et al, 2010). Many factors can affect landslides or slope failure, but in general the factors are slope geometry, materials (Soil or Rock), orientation of geologic feature (Strike & Dip), geo- logical structure (Fault and Fold), groundwater, seismic activity or static & dynamic load, and weathering.
Figure 1. One of the open slope mining on coal mine in Indonesia. et al, 2010). Many factors can affect landslides or slope failure, but in general the factors are slope geometry, materials (Soil or Rock), orientation of geologic feature (Strike & Dip), geo- logical structure (Fault and Fold), groundwater, seismic activity or static & dynamic load, and weathering.
Figure 3. Landslide section which consists of crest, body, and toe of the slope in the field.
Figure 3. Landslide section which consists of crest, body, and toe of the slope in the field.
Figure 4. Landslide features in the authors research area in each section.
Figure 4. Landslide features in the authors research area in each section.
Table 1. Slope material for calculate static FoS in authors research area. In normal circumstance research area mine waste dump slope has a good static Factor of Safety (FoS) value = 1.299 (Figure 5) using material properties as shown in Table 1 below. But in reality slope failure still occurred in this mine waste dump slope despite having a good FoS value. The foundation material and mine waste dump on the slopes are soil. This can be known from the UCS (uniaxial compressive strength) surface sample as well as sub-surface sample (wellsite) that have < 1 MPa from the laboratory test result.
Table 1. Slope material for calculate static FoS in authors research area. In normal circumstance research area mine waste dump slope has a good static Factor of Safety (FoS) value = 1.299 (Figure 5) using material properties as shown in Table 1 below. But in reality slope failure still occurred in this mine waste dump slope despite having a good FoS value. The foundation material and mine waste dump on the slopes are soil. This can be known from the UCS (uniaxial compressive strength) surface sample as well as sub-surface sample (wellsite) that have < 1 MPa from the laboratory test result.
Figure 6. Probabilistic analysis to know the changes in research area material parameter values Waste dump material is an undrained material which is material condition when the pore water is unable to drain out or the rate of loading is much quicker than the rate at which the pore water is able to drain out. When performing back analysis in mine waste dump slope of the research area, it is assumed that a landslide occurs when FoS = 1. With using probabilistic analysis in the waste dump material, the result is the closest possibility for the slope landslide failure is when the cohesion and unit weight of the materials decrease to 88.97 kPa and increase to 24 kN/m? (Figure 6-7).
Figure 6. Probabilistic analysis to know the changes in research area material parameter values Waste dump material is an undrained material which is material condition when the pore water is unable to drain out or the rate of loading is much quicker than the rate at which the pore water is able to drain out. When performing back analysis in mine waste dump slope of the research area, it is assumed that a landslide occurs when FoS = 1. With using probabilistic analysis in the waste dump material, the result is the closest possibility for the slope landslide failure is when the cohesion and unit weight of the materials decrease to 88.97 kPa and increase to 24 kN/m? (Figure 6-7).
Table 2. Slope material after slope failure has occurred (FoS = 1) from back analysis. Slope material is very sensitive to the influence of groundwater or pore water pressure, con- sidering that the material in the mine waste dump is dominated by soil (clay grain sized). The effect of groundwater which increases the unit weight will increase the weight of the waste dump on the slope body plus the effect of groundwater will reduce the binding power between particles (cohesion), so that the strength of the slope will be reduced and failure occurs. OCthoensrnétwienlt mmmitean! Tt. tailed cama Fawléi nen et Laven ie thn fall ¢ein ice hbearnntiwess: 4han clravwn Mine waste dump slope failure back analysis gives a possibility decreasing or increasing material properties that makes slope failure. It also answers the hypothesis that the authors initially determined earlier in this research. In this case study the closest possibility for the slope landslide failure is when the cohesion and unit weight of the materials decrease to 88.97 kPa and increase to 24 kN/m? as shown in Table 2. This shows that the amount of water pres- sure from the recharge area that supply the slope body can reduce the strength and the slope factor of safety. This is also proven from the photogrammetry analysis with result Circular- Earth Flow complex landslide type that occurred in the mine waste dump slope of the research area. The material cohesion (c) is reduced by 9.54 % and increase the material unit weight value by 3.52 %.
Table 2. Slope material after slope failure has occurred (FoS = 1) from back analysis. Slope material is very sensitive to the influence of groundwater or pore water pressure, con- sidering that the material in the mine waste dump is dominated by soil (clay grain sized). The effect of groundwater which increases the unit weight will increase the weight of the waste dump on the slope body plus the effect of groundwater will reduce the binding power between particles (cohesion), so that the strength of the slope will be reduced and failure occurs. OCthoensrnétwienlt mmmitean! Tt. tailed cama Fawléi nen et Laven ie thn fall ¢ein ice hbearnntiwess: 4han clravwn Mine waste dump slope failure back analysis gives a possibility decreasing or increasing material properties that makes slope failure. It also answers the hypothesis that the authors initially determined earlier in this research. In this case study the closest possibility for the slope landslide failure is when the cohesion and unit weight of the materials decrease to 88.97 kPa and increase to 24 kN/m? as shown in Table 2. This shows that the amount of water pres- sure from the recharge area that supply the slope body can reduce the strength and the slope factor of safety. This is also proven from the photogrammetry analysis with result Circular- Earth Flow complex landslide type that occurred in the mine waste dump slope of the research area. The material cohesion (c) is reduced by 9.54 % and increase the material unit weight value by 3.52 %.
Figure 7. Back analysis in authors research area with assumption FoS = 1.
Figure 7. Back analysis in authors research area with assumption FoS = 1.
Related topics:
Geotechnical EngineeringSlope Stability AnalysisFactor of Safety
580 California St., Suite 400
San Francisco, CA, 94104
© 2025 Academia. All rights reserved