Seismic and static 3D stability of two-stage rock slope based on Hoek–Brown failure criterion

2016 ◽  
Vol 53 (3) ◽  
pp. 551-558 ◽  
Author(s):  
X.-L. Yang ◽  
Z.-X. Long

Two-stage slope is beneficial to improve slope stability in comparison with single-stage slope. Based on nonlinear Hoek–Brown criterion, a three-dimensional failure mechanism is employed to estimate the stability of two-stage rock slope, with the effect of seismic inertia force being taken into account. A generalized tangential technique is used to formulate the stability factor problem as a classical optimization problem corresponding to the dissipated energy. The upper-bound solutions are obtained by minimizing the objective function with respect to the location of sliding body center and the location of tangency point. The seismic inertia force is considered and incorporated into the objective function. In comparison with previously published solutions using the linear Mohr–Coulomb criterion, the validity of the present solutions is shown. The analytical expressions for two-stage slope are derived to estimate the seismic stability of slopes. Numerical results for different types of rocks are presented for practical use in engineering, and the effects of different parameters on slope stability are discussed.

2020 ◽  
Vol 53 (2F) ◽  
pp. 65-82
Author(s):  
Rebaz Qader

The study of slope stability along the proposed Lerabire road in the Mergasur town, in Erbil city, Kurdistan region of NE-Iraq is carried out. To evaluate the stability of slopes, twenty stations were selected along the mentioned road, two stations in the rock slopes of the Shiranish Formation, eleven stations in the Bekhme Formation, six stations in the Qamchuqa Formation, and one station in the Sarmord Formation. In this study, the stability of rock slopes has been evaluated by the Landslide Possibility Index system. The results of the Landslide Possibility Index category in the rock slopes along the proposed Lerabire road ranges from a very low to low for rock slopes in stations 1 and 2 (marl and marly limestone of the Shiranish Formation, Moderate for rock slopes in stations 3, 4 and 19 (limestone of the Bekhme Formation), High for rock slopes in the stations 5, 6, 7, 8, 9, 10, 11 (limestone of the Bekhme Formation), stations 12, 17 (limestone and marly limestone of the Qamchuqa Formation), station 20 (limestone of the Sarmord Formation and very high for rock slopes in the stations 13, 14, 15, 16 (limestone and marly limestone of the Qamchuqa Formation), station 18 (limestone of the Bekhme Formation). According to Landslide Possibility Index category, the hazard category is Low in station 1 in the Shiranish Formation, but in station 2, 3, 4 and 19 are Moderate, moreover, in the station 5, 11, 12, 17, 18 and 20 are high. The rock slope assessment indicated that the height of the slope face, slope angle, a high degree of weathering, and discontinuities spacing are the factors that increase the failure possibility. To prevent landslide the ditch method is used in the Shiranish Formation rock slopes, the reinforcement techniques are used in the Behkme Formation rock slopes and rock removal methods are used in Qamchuqa and Sarmord Formation rock slopes.


2021 ◽  
Vol 13 (7) ◽  
pp. 4046
Author(s):  
Vittoria Capobianco ◽  
Kate Robinson ◽  
Bjørn Kalsnes ◽  
Christina Ekeheien ◽  
Øyvind Høydal

Vegetation can be used as a nature-based solution (NBS) to restore rivers and mitigate water-triggered processes along streambanks. Roots are well known to improve the overall stability of slopes through hydro-mechanical reinforcement within the rooted zone. Vegetation-based solutions require the selection of species that are most suitable for specific locations, and they are aimed at restoring the natural state and function of river systems in support of biodiversity, flood management, and landscape development. Selecting a combination of different species along different zones of the riverbank can improve the conditions for the river system with regard to biodiversity and stability. Therefore, more studies are needed to investigate how the combination of a variety of different plant species can improve the stability of the riverbank. This paper presents a methodological approach for slope stability modeling including vegetation as well as the results obtained from a series of slope stability calculations adopting the proposed methodology. The analyses were carried out for critical shallow (≤3 m deep) shear planes of ideal benchmark slopes covered with four different plant combinations—(i) only grass, (ii) grass and shrubs, (iii) only trees, and (iv) trees, shrubs, and grass—for species typically found along streams in southeastern Norway. In this desk study, two types of tree species were selected, namely Norway spruce (Picea abies) and Downy birch (Betula pubescens). The Goat willow (Salix caprea) was selected as a shrub, while a common mixed-grass was chosen as grass. Vegetation features were obtained from the literature. The methodology was used for two main cases: (1) considering only the mechanical contribution of vegetation and (2) considering both the hydrological and mechanical reinforcement of vegetation. The main outcome of the numerical modeling showed that the purely mechanical contribution of vegetation to slope stability could not be decoupled from the hydrological reinforcement in order to have a realistic assessment of the roots improvement to the stability. The most critical shear surfaces occurred below the rooted zone in all cases, and the best performance was obtained using the combinations including trees. Considering the typical climate conditions in Norway, the hydro-mechanical reinforcement was most effective in the spring and for combinations including low height vegetation (i.e., grass and shrubs). The study concludes that a mixed combination of vegetation (trees, shrubs, and grass) is the most suitable for reaching the highest hydro-mechanical reinforcement of streambanks, together with erosion protection and boosting the ecosystem biodiversity. The current study can help practitioners determine which vegetation cover combination is appropriate for improving the current stability of a streambank with restoration practices.


2020 ◽  
pp. 65-75
Author(s):  
Liudmyla Skochko ◽  
Viktor Nosenko ◽  
Vasyl Pidlutskyi ◽  
Oleksandr Gavryliuk

The stability of the slope in the existing and design provisions is investigated, the constructive decisions of retaining walls on protection of the territory of construction of a residential complex in a zone of a slope are substantiated. The stability of the slope when using rational landslide structures is estimated. The results of the calculation of the slope stability for five characteristic sections on the basis of engineering-geological survey are analyzed. For each of the given sections the finite-element scheme according to the last data on change of a relief is created. The slope was formed artificially by filling the existing ravine with construction debris from the demolition of old houses and from the excavation of ditches for the first houses of the complex. Five sections along the slope are considered and its stability in the natural state and design positions is determined. Also the constructive decisions of retaining walls on protection of the territory of construction of a residential complex as along the slope there are bulk soils with various difference of heights are substantiated. This requires a separate approach to the choice of parameters of retaining walls, namely the dimensions of the piles and their mutual placement, as well as the choice of the angle of the bulk soil along the slope. The calculations were performed using numerical simulation of the stress-strain state of the system "slope soils-retaining wall" using the finite element method. An elastic-plastic model of soil deformation with a change in soil parameters (deformation module) depending on the level of stresses in the soil is adopted. Hardening soil model (HSM) used. Calculations of slope stability involve taking into account the technological sequence of erection of retaining walls and modeling of the phased development of the pit. The simulation was performed in several stages: Stage 1 - determination of stresses from the own shaft, Stage 2 - assessment of slope stability before construction, Stage 3 - installation of retaining wall piles, Stage 4 - assessment of slope stability after landslides. Based on these studies, practical recommendations were developed for the design of each section of the retaining wall in accordance with the characteristic cross-sections.


2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Faridha Aprilia ◽  
I Gde Budi Indrawan

The stability of rock slopes is controlled by several factors, such as the intact rock strength, discontinuity characteristics, groundwater condition, and slope geometry. Limit equilibrium (LE) analyses have been commonly used in geotechnical practice to evaluate the stability of rock slopes. A number of methods of LE analyses, ranging from simple to sophisticated methods, have been developed. This paper presents stability analyses of rock slopes at the Batu Hijau open mine in Sumbawa Barat using various methods of LE analyses. The LE analyses were conducted at three cross sections of the northern wall of the open mine using the Bishop Simplified, Janbu Simplified, Janbu Generalised, and General Limit Equilibrium (GLE) methods in Slide slope stability package. In addition, a Plane Failure (PF) analysis was performed manually. Shear strength data of the discontinuity planes used in the LE analyses were obtained from back analyses of previous rock slope failures. The LE analysis results showed that the rock slopes were likely to have shallow non-circular critical failure surfaces. The factor of safety (Fs) values obtained from the Bishop Simplified, Janbu Simplified, Janbu Generalised, and GLE methods were found to be similar, while the Fs values obtained from the PF method were higher than those obtained from the more rigorous methods. Keywords: Batu Hijau mine, Bishop Simplified, Janbu Simplified, Janbu Generalised, limit equilibrium analyses, general limit equilibrium, rock slope stability, plane failure.


2013 ◽  
Vol 634-638 ◽  
pp. 3277-3281 ◽  
Author(s):  
Shi Guo Sun ◽  
Hong Yang ◽  
Chun Sheng Li ◽  
Bao Lin Zhang ◽  
Jia Wang ◽  
...  

The stability state of slope rock mass is relating to each other’s relative location during the transformation from open-pit to underground mining, it’s the most disadvantageous influence on the slope stability when the underground mining area is located in the toe of slope, and it’s the best influence as in the slope extracellular region. Slope stability factor changes with the geometric dimensions of underground mining increased, but not in direct proportion. Under the condition of constant geometric dimensions of mining area, the influence on slope stability is changing with the mining depth increased. Thus indicating that the influence on slope stability by underground mining has its spatial property, and to determine the specific influence value requires a combination of many factors, such as the relationship of relative spatial position, the geometric dimensions of mining area, engineering geological conditions and so on.


2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
K. Ma ◽  
N. W. Xu ◽  
Z. Z. Liang

A high-resolution microseismic (MS) monitoring system was implemented at the right bank slope of the Dagangshan hydropower station in May 2010 to analyse the slope stability subjected to continuous excavation. The MS monitoring system could real-time capture a large number of seismic events occurring inside the rock slope. The identification and delineation of rock mass damage subject to excavation and consolidation grouting can be conducted based on the analysis of tempospatial distribution of MS events. However, how to qualitatively evaluate the stability of the rock slope by utilizing these MS data remains challenging. A damage model based on MS data was proposed to analyse the rock mass damage, and a 3D finite element method model of the rock slope was also established. The deteriorated mechanical parameters of rock mass were determined according to the model elements considering the effect of MS damage. With this method, we can explore the effect of MS activities, which are caused by rock mass damage subjected to excavation and strength degradation to the dynamic instability of the slope. When the MS damage effect was taken into account, the safety factor of the rock slope was reduced by 0.18 compared to the original rock slope model without considering the effect. The simulated results show that MS activities, which are subjected to excavation unloading, have only a limited effect on the stability of the right bank slope. The proposed method is proven to be a better approach for the dynamical assessment of rock slope stability and will provide valuable references for other similar rock slopes.


2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Wenchen Fan ◽  
Ping Cao ◽  
Ke Zhang ◽  
Kaihui Li ◽  
Chong Chen

Chengmenshan copper mine, located at Jiujiang city in the Jiangxi Province, is a rarely lakeside open-pit mine in China. Since the open-pit is very close to Sai Lake, the seasonally changed water level and the distance between lake and slope have great influence to the stability of open-pit slope. Based on the drill data and geological sections, a numerical model of the slope is built. With the fluid-mechanical interaction associated, the stability of the slopes is numerically analyzed, in which different lake water levels and lake-slope distances are taken into consideration. The comparative analysis shows that a larger lake-slope distance can promise better slope stability and weaken the sensitivity of slope stability to water. The stability of slopes with different heights is analyzed to find that the stability weakens and the sensitivity is enhanced with the height increasing. To the most serious situation, the slope height and the lake water level being 238 m and 17.2 m, respectively, theFsvalue equals 1.18945 which is extremely closed to the allowable safety factor of 1.20 for slope design. According to the minimumFsfor slope design, the minimum distance between lake and open-pit slope is found to be 60 m.


Geosciences ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 417 ◽  
Author(s):  
Abbate ◽  
Longoni ◽  
Ivanov ◽  
Papini

Landslides over steep slopes, floods along rivers plains and debris flows across valleys are hydrogeological phenomena typical for mountain regions. Such events are generally triggered by rainfall, which can have large variability in terms of both its intensity and volume. Furthermore, terrain predisposition and the presence of some disturbances, such as wildfires, can have an adverse effect on the potential risk. Modelling the complex interaction between these components is not a simple task and cannot always be carried out using instability thresholds that only take into account the characteristics of the rainfall events. In some particular cases, external factors can modify the existing delicate equilibrium on the basis of which stability thresholds are defined. In particular, events such as wildfires can cause the removal of vegetation coverage and the modification of the soil terrain properties. Therefore, wildfires can effectively reduce the infiltration capacity of the terrain and modify evapotranspiration. As a result, key factors for slope stability, such as the trend of the degree of saturation of the terrain, can be strongly modified. Thus, studying the role of wildfire effects on the terrain’s hydrological balance is fundamental to establish the critical conditions that can trigger potential slope failures (i.e., shallow landslides and possible subsequent debris flows). In this work, we investigate the consequences of wildfire on the stability of slopes through a hydrological model that takes into account the wildfire effects and compare the results to the current stability thresholds. Two case studies in the Ardenno (IT) and Ronco sopra Ascona (CH) municipalities were chosen for model testing. The aim of this paper is to propose a quantitative analysis of the two cases studies, taking into account the role of fire in the slope stability assessment. The results indicate how the post-fire circumstances strongly modify the ability of the terrain to absorb rainfall water. This effect results in a persistently drier terrain until a corner point is reached, after which the stability of the slope could be undermined by a rainfall event of negligible intensity.


2013 ◽  
Vol 438-439 ◽  
pp. 1376-1379
Author(s):  
Jian Ping He ◽  
Ya Li Wang

Rock nature is mainly controlled by joint-fissur, the stability of rock slope is mainly controlled by the joint surface, the destruction of the slope caused wedge instability formed by joint plane cutting. Stereographic projection can analyze simply and intuitively spatial association relations of straight line and plane in geological body, judge high-cutting slope stability and decisive factor of judge stability of high-cutting slope by means of direction and tendency relationship of rock slope and structural plane. This paper uses stereographic projection to analyze and judge high-cutting slope stability formed by artificial mechanical excavation in Qingxi, and decisive factor of stability according to deformation and fracture and the trends in the high-cutting slope regional, puts forward the high-cutting slope control measures and methods to ensure slope stability and security.


Horticulturae ◽  
2021 ◽  
Vol 7 (9) ◽  
pp. 310
Author(s):  
Alessandra Francini ◽  
Stefania Toscano ◽  
Daniela Romano ◽  
Francesco Ferrini ◽  
Antonio Ferrante

Plants can reduce erosion during heavy raining periods and improve slope stability through their root morphology, development, biomass, and architecture. Heavy rains can increase erosion, becoming a danger for traffic and people who live around slopes. The control of slope stability is often required in urban and peri-urban environments, and for this reason ornamental species can be appropriately selected for a dual use, namely improving the aesthetical value of green areas along the urban and suburban roads and mitigating the erosion effects. The species used must have good tolerance to abiotic stresses, such as high and low temperature, drought, pollution and nutrient deficiency. Otherwise, their limited growth can reduce their beneficial effects. Ornamental plants that can be used for reducing the erosion of slopes must be in full growth during periods with a higher incidence of rains and must also be compatible with the temperature ranges in different seasons. These species can be also selected for their ability to avoid erosion and enhance the stability of slopes. In this review, the biological contribution of plants for improving slope stability has been reported and discussed with a special focus attention on the Mediterranean environment. Particular emphasis has been placed on root biomass changes and root growth parameters, considering their role as potential markers for selecting suitable plants to be used for enhancing slope stability. A brief description of planting on slopes and root growth has been also considered and discussed.


Sign in / Sign up

Export Citation Format

Share Document