Comparison between the mechanical behavior of barriers against rock fall vs debris flows

2013 ◽  
pp. 691-696
Author(s):  
A Segalini ◽  
R Brighenti ◽  
A Ferrero ◽  
A Ferrero
Keyword(s):  
Mechanical Behavior ◽  
Debris Flows ◽  
Rock Fall

Anticipating cascading risks at the imminent Hochvogel peak failure

2021 ◽  
Author(s):  
Johannes Leinauer ◽  
Manfred Meindl ◽  
Benjamin Jacobs ◽  
Verena Stammberger ◽  
Michael Krautblatter
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Point Clouds ◽  
Volume Estimation ◽  
Rock Fall ◽  
Recent Case ◽  
Hazard Evaluation ◽  
Event Analysis ◽  
Worst Case ◽  
Cascading Effects

<p>Climatic changes are exacerbating the risk of alpine mass movements for example through more frequent and extreme heavy precipitation events. To cope with this situation, the monitoring, anticipation, and early warning of rock slope failures based on process dynamics is a key strategy for alpine communities. However, only investigating the release area of an imminent event is insufficient, as the primary hazard can trigger or increase secondary hazards like debris flows or the damming of a river. Nevertheless, recent case studies dealing with successive hazards are rarely existent for the Calcareous Alps. In this study, we precisely investigate the cascading effects resulting from an imminent rock fall and perform a pre-event analysis instead of back-modelling of a past event.</p><p>The Hochvogel summit (2592 m a.s.l., Allgäu Alps, Germany/Austria) is divided by several pronounced clefts that separate multiple instable blocks. 3D-UAV point clouds reveal a potentially instable mass of 260,000 m³ in six main subunits. From our near real time monitoring system (Leinauer et al. 2020), we know that some cracks are opening at faster pace and react differently to heavy rainfall, making a successive failure of subunits likely. However, pre-deformations are not yet pronounced enough to decide on the exact expected volume whereas secondary effects are likely as the preparing rock fall mass will be deposited into highly debris-loaded channels. Therefore, we developed different rock fall scenarios from the gathered monitoring information, which we implemented into a RAMMS modelling of secondary debris flows. To obtain best- and worst-case results, each scenario is calculated with different erosion parameters in the runout channel. The models are calibrated with a well-documented debris flow event at Roßbichelgraben (10 km NW and similar lithology) and are supported by field investigations in the runout channel including electrical resistivity tomography profiles (ERT) for determination of the depth of erodible material as well as a drone survey for mapping the area and the generation of an elevation model.</p><p>Here we show a comprehensive scenario-based assessment for anticipating cascading risks at the Hochvogel from initial rock failure volume estimation to debris flow evolution and potential river damming. This recent case study from an alpine calcareous peak is an excellent and rare chance to gain insights into cascading risks modelling and an improved hazard evaluation.</p>

scholarly journals LANDSLIDE RUNOUT DISTANCE PREDICTION BASED ON MECHANISM AND CAUSE OF SOIL OR ROCK MASS MOVEMENT

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Muhammad Qarinur
Keyword(s):  
Rock Mass ◽  
Linear Regression ◽  
Debris Flows ◽  
Empirical Equation ◽  
Mass Movement ◽  
Rock Fall ◽  
Hazard Evaluation ◽  
Linear Regression Method ◽  
Rock Falls ◽  
The Impact

Landslide often occurs in tropical hills area, such as Indonesia. Research on landslide hazard evaluation is necessary to decrease the impact in affected and surrounding areas. Empirical-statistical methods can be used to predict landslide run out distance in an effort to avoid the danger of landslide occurrences. This study aims to determine the correlation between landslide run out distance against high, slope, and volume based on mechanisms and causes of soil or rock mass movement. Data mainly from 106 landslides in Indonesia has been analyzed to search for possible correlations and empirical correlations, there are 34 rotational slides, 54 translational slides, 8 debris flows, and 10 rock falls. Analysis begins by studying the characteristics of the data (explanatory data analysis) and then analyzed by using empirical methods such as geomorphological assessment and geometrical approaches. Then the data is processed by simple linear regression and multiple linear regression method using the R software. The results obtained from the analysis of the general empirical equation form of the correlation between height (H) and run out distance (L) is 1.066H1.093, respectively. This results indicate the higher altitude slopes, the greater distance will happen. The results of the analysis correlation between height and run out distance for the type of mass movements for rotational is L=1.346+1.788 H, translational is L=-3.88+1.578H, debris flow is L=0.682H1.29, and rock fall is L=2.223H0.897. This result shows debris flows landslide run out distance is greater than rotational, translational and rock fall. The results of the analysis correlation between height and run out distance of the trigger due to the rain is L=1.267H1.027, and by an earthquake is L=0.574H1.38. This results show run out distance caused by an earthquake is larger than caused by rain. The correlation between the run out distance and volume (V) yields empirical equation which is V=0.772L2.108. This results indicate that greater run out distance is affected by the growing volume of mass movement. The results of the analysis correlation between height and slope (θ) to run out distance is L=1.448H1.062 tan θ-0,482. This results indicate that slope has a significant impact on the value of landslide run out distance.

scholarly journals Numerical simulation of debris flows triggered from the Strug rock fall source area, W Slovenia

2006 ◽  
Vol 6 (2) ◽  
pp. 261-270 ◽  
Author(s):  
M. Mikoš ◽  
R. Fazarinc ◽  
B. Majes ◽  
R. Rajar ◽  
D. Žagar ◽  
...  
Keyword(s):  
Debris Flow ◽  
Mathematical Models ◽  
Debris Flows ◽  
Model Calibration ◽  
Source Area ◽  
Rock Fall ◽  
One Dimensional ◽  
Engineering Measures ◽  
The Village ◽  
Extreme Scenario

Abstract. The Strug landslide was triggered in December 2001 as a rockslide, followed by a rock fall. In 2002, about 20 debris flows were registered in the Kosec village; they were initiated in the Strug rock fall source area. They all flowed through the aligned Brusnik channel, which had been finished just before the first debris flow reached the village in April 2002. Debris flow events were rainfall-induced but also governed by the availability of rock fall debris in its zone of accumulation. After 2002 there was not enough material available for further debris flows to reach the village. Nevertheless, a decision was reached to use mathematical modeling to prepare a hazard map for the village for possible new debris flows. Using the hydrological data of the Brusnik watershed and the rheological characteristics of the debris material, 5 different scenarios were defined with the debris flow volumes from 1000 m3 to a maximum of 25 000 m3. Two mathematical models were used, a one-dimensional model DEBRIF-1D, and a two-dimensional commercially available model FLO-2D. Due to the lack of other field data, data extracted from available professional films of debris flows in 2002 in the Kosec village were used for model calibration. The computational reach was put together from an 800-m long upstream reach and 380-m long regulated reach of the Brusnik channel through the village of Kosec. Both mathematical models have proved that the aligned Brusnik channel can convey debris flows of the volume up to 15 000 m3. Under the most extreme scenario a debris flow with 25 000 m3 would locally spill over the existing levees along the regulated Brusnik channel. For this reason, additional river engineering measures have been proposed, such as the raising of the levees and the construction of a right-hand side sedimentation area for debris flows at the downstream end of the regulated reach.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

The influence of the addition of ground olive stone on the thermo-mechanical behavior of compressed earth blocks

2020 ◽  
Vol 108 (2) ◽  
pp. 203
Author(s):  
Samia Djadouf ◽  
Nasser Chelouah ◽  
Abdelkader Tahakourt
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Mechanical Behavior ◽  
Agricultural Waste ◽  
Hydraulic Press ◽  
Dry Density ◽  
Olive Stone ◽  
Compressed Earth Blocks ◽  
Clay Matrix ◽  
Earth Blocks

Sustainable development and environmental challenges incite to valorize local materials such as agricultural waste. In this context, a new ecological compressed earth blocks (CEBS) with addition of ground olive stone (GOS) was proposed. The GOS is added as partial clay replacement in different proportions. The main objective of this paper is to study the effect of GOS levels on the thermal properties and mechanical behavior of CEB. We proceeded to determining the optimal water content and equivalent wet density by compaction using a hydraulic press, at a pressure of 10 MPa. The maximum compressive strength is reached at 15% of the GOS. This percentage increases the mechanical properties by 19.66%, and decreases the thermal conductivity by 37.63%. These results are due to the optimal water responsible for the consolidation and compactness of the clay matrix. The substitution up to 30% of GOS shows a decrease of compressive strength and thermal conductivity by about 38.38% and 50.64% respectively. The decrease in dry density and thermal conductivity is related to the content of GOS, which is composed of organic and porous fibers. The GOS seems promising for improving the thermo-mechanical characteristics of CEB and which can also be used as reinforcement in CEBS.

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