scholarly journals Direct observations of a three million cubic meter rock-slope collapse with almost immediate initiation of ensuing debris flows

Geomorphology ◽  
2020 ◽  
Vol 351 ◽  
pp. 106933 ◽  
Author(s):  
Fabian Walter ◽  
Florian Amann ◽  
Andrew Kos ◽  
Robert Kenner ◽  
Marcia Phillips ◽  
...  
Keyword(s):  
Debris Flows ◽  
Rock Slope ◽  
Direct Observations ◽  
Slope Collapse ◽  
Million Cubic Meter

Experimental Study on the Dynamic Destruction of Rock Slope with the White DSCM Method

2011 ◽  
Vol 243-249 ◽  
pp. 3873-3876
Author(s):  
Lai Gui Wang ◽  
Hong Zhu Zhang ◽  
Mei Sheng Feng
Keyword(s):  
Rock Slope ◽  
Crack Formation ◽  
Space Form ◽  
Dynamic Failure ◽  
Weak Layer ◽  
Speckle Correlation ◽  
Slope Collapse ◽  
The Stability ◽  
Stability Of Rock Slope ◽  
Digital Speckle Correlation

To study the stability of rock slope under dynamic load,the digital speckle correlation measurement (DSCM) is used for dynamic failure of rock slope containing two weak layers.It observes the displacement field, deformation field, and stress field during the process of crack formation, crack through the slope and slope collapse. Experimental results show that the initial deformation cracking on the surface around the structure of the weak layer, and then extended to top and the foot of the slope, and finally through the loose structure.The slope stability is controlled by the weak layer’s angle, the space form of the weak layer and the slope Mechanical Properties.It gives the failue model of the different positon in the slope.

scholarly journals Change Detection and Feature Extraction of Debris-Flow Initiation by Rock-Slope Failure Using Point Cloud Processing

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xiaoying He ◽  
Zeqing Yu ◽  
John M. Kemeny ◽  
Ann Youberg ◽  
Yunkun Wang
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Point Cloud ◽  
Slope Failure ◽  
Rock Slope ◽  
Point Cloud Data ◽  
Cloud Data ◽  
Cloud Processing ◽  
Point Cloud Processing ◽  
Debris Flow Initiation

Our understanding of debris-flow initiation by slope failure is restricted by the challenge of acquiring accurate geomorphic features of debris flows and the structural setting of the rock mass in the remote mountainous terrain. Point cloud data of debris flows in Sabino Canyon, Tucson, Arizona, July 2006, with initiation by joint-controlled rock slope were obtained using multitemporal LiDAR scanning. Topographic changes were detected by comparing historical LiDAR scanning data of this area since 2005 by adopting open-source CloudCompare software. The results showed persistent scour and erosion in the debris flows after 2006. Point cloud data of joint-controlled rock in the initiation zone were generated by the means of photogrammetry using Pix4D software. The joint planes, the dip direction and the dip value of the joint plane, the joint spacing, and the joint roughness were therefore acquired by point cloud processing. Our study contributes a foundation for analyzing the relationship between the rock features, the generation of slope failure, and the initiation of debris flows.

scholarly journals Defining and characterizing wood-laden flows in rivers using home videos

2018 ◽  
Vol 40 ◽  
pp. 02014 ◽  
Author(s):  
V. Ruiz-Villanueva ◽  
L. Bürkli ◽  
B. Mazzorana ◽  
L. Mao ◽  
D. Ravazzolo ◽  
...  
Keyword(s):  
Organic Material ◽  
Debris Flows ◽  
Management Strategies ◽  
Clear Water ◽  
Home Videos ◽  
Direct Observations ◽  
Wood Debris ◽  
Flow Phenomena ◽  
First Time

Organic material (i.e., trees, branches, wood in general) is commonly neglected among the classical criteria to distinguish flow types, mostly due to the lack of direct observations of flows in which this load is significant. However, in forested basins, large amounts of wood can be transported. Here we define and characterize, for the first time, wood-laden flows and show that these flows may occur repeatedly in a river basin, carrying substantial amount of organic material, with probable impacts on the ecosystem and potential hazards. We propose a novel classification of flows from clear water to hypercongested wood debris flows, according to the composition of sediment, wood and water. Our results will contribute to a better understanding of flow phenomena in forested river basins, which may facilitate the design of better management strategies.

scholarly journals Physical Modeling Test on Deformation and Failure of Rock Slope with New Support System

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Zhigang Tao ◽  
Tongxing Zhang ◽  
Daoyong Zhu ◽  
Weili Gong ◽  
Manchao He
Keyword(s):  
Large Deformation ◽  
Poisson’S Ratio ◽  
Rock Slope ◽  
Surrounding Rock ◽  
Poisson's Ratio ◽  
Negative Poisson’S Ratio ◽  
Deformation And Failure ◽  
Entire Process ◽  
Negative Poisson's Ratio ◽  
Slope Collapse

In order to explore the monitoring and control method of rock slope, indoor physical model testing of collapse control and monitoring were carried out with the example of a rock slope collapse area project in Jietai Temple in Beijing, China, as the prototype. Based on the similarity theory, in this study, a new structural support with Negative Poisson’s Ratio bolt and flexible anchored net was utilized to reinforce the rock slope. Following a graded loading sequence, the collapse failure characteristics and the overall control effect of energy absorption reinforcement measures were explored. The experimental results demonstrated that the entire process of slope collapse presented four distinct stages of failure: fracture generation, fracture propagation, partial collapse, and overall collapse. The full-field displacement nephogram and the displacement monitoring point of the collapse area indicated that the large deformation and failure of the collapsed surrounding rock were effectively controlled, while the Negative Poisson’s Ratio bolt and the flexible anchored net had good reinforcement effects. The experimental stress record presented that the change of pressure curve was an apparent regularity in the entire process of slope collapse, which reflects the change state of internal force of surrounding rock; it includes the function of monitoring of slope collapse. It was indicated that the Negative Poisson’s Ratio bolt along with the large-deformation flexible anchored net had good reinforcement monitoring effect on the rock slope collapse disaster.

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

Metallurgical Effects of Grain Boundary Ledges

1977 ◽  
Vol 35 ◽  
pp. 126-129
Author(s):  
L.E. Murr
Keyword(s):  
Grain Boundary ◽  
Quantitative Data ◽  
Mechanical Treatment ◽  
Unit Length ◽  
Physical And Mechanical Properties ◽  
Direct Observations ◽  
Transmission Electron ◽  
Properties Of Materials ◽  
Thermo Mechanical Treatment ◽  
Ledge Density

Ledges in grain boundaries can be identified by their characteristic contrast features (straight, black-white lines) distinct from those of lattice dislocations, for example1,2 [see Fig. 1(a) and (b)]. Simple contrast rules as pointed out by Murr and Venkatesh2, can be established so that ledges may be recognized with come confidence, and the number of ledges per unit length of grain boundary (referred to as the ledge density, m) measured by direct observations in the transmission electron microscope. Such measurements can then give rise to quantitative data which can be used to provide evidence for the influence of ledges on the physical and mechanical properties of materials.It has been shown that ledge density can be systematically altered in some metals by thermo-mechanical treatment3,4.

Direct Observations of the Epitaxial Growth of Sputtered Ag on Si

1973 ◽  
Vol 31 ◽  
pp. 122-123
Author(s):  
J. S. Maa ◽  
Thos. E. Hutchinson
Keyword(s):  
Epitaxial Growth ◽  
Film Growth ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Microscopy Technique ◽  
Direct Observations ◽  
In Situ Electron Microscopy ◽  
Beam Sputtering ◽  
The Subject

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.

Void-Lattice Formation in Natural Fluorite by Electron Irradiation

1976 ◽  
Vol 34 ◽  
pp. 614-615 ◽  
Author(s):  
L.E. Murr
Keyword(s):  
Electron Microscope ◽  
Electron Irradiation ◽  
Heavy Ion ◽  
High Energy ◽  
Stoichiometric Ratio ◽  
Direct Observations ◽  
Transmission Electron ◽  
Anion Vacancies ◽  
Cation And Anion Vacancies ◽  
Lattice Formation

The production of void lattices in metals as a result of displacement damage associated with high energy and heavy ion bombardment is now well documented. More recently, Murr has shown that a void lattice can be developed in natural (colored) fluorites observed in the transmission electron microscope. These were the first observations of a void lattice in an irradiated nonmetal, and the first, direct observations of color-center aggregates. Clinard, et al. have also recently observed a void lattice (described as a high density of aligned "pores") in neutron irradiated Al2O3 and Y2O3. In this latter work, itwas pointed out that in order that a cavity be formed,a near-stoichiometric ratio of cation and anion vacancies must aggregate. It was reasoned that two other alternatives to explain the pores were cation metal colloids and highpressure anion gas bubbles.Evans has proposed that void lattices result from the presence of a pre-existing impurity lattice, and predicted that the formation of a void lattice should restrict swelling in irradiated materials because it represents a state of saturation.

Direct observation of Fe-Al-Zn ternary intermetallic compound and its transformation during the early stage of hot-dip galvanizing

1993 ◽  
Vol 51 ◽  
pp. 1116-1117
Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii
Keyword(s):  
Intermetallic Compound ◽  
Reaction Rate ◽  
Diffusion Rate ◽  
Early Stage ◽  
Zinc Bath ◽  
Steel Sheets ◽  
Direct Observations ◽  
Solid Iron ◽  
Iron And Zinc ◽  
Ternary Intermetallic Compound

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.

Pengaruh Modal Sosial Terhadap Perkembangan Pariwisata di Kepulauan Riau

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Nurul Nadjmi
Keyword(s):  
Social Capital ◽  
Qualitative Research ◽  
System Approach ◽  
Research Method ◽  
Analytic Approach ◽  
Community Groups ◽  
Study Strategy ◽  
Direct Observations ◽  
Descriptive Qualitative

Kepulauan Riau merupakan provinsi yang terdiri dari beberapa pulau diantaranya Pulau Batam, Pulau Bintan dan Pulau Karimun. Modal sosial merupakan serangkaian nilai dan norma informal yang dimiliki oleh kelompok masyarat dalam membagun kerjasamanya. Lingkup penelitian pada pembahasan ini adalah terfokus pada pengaruh modal sosial terhadap perkembangan pariwisata di Kepulauan Riau dalam hal ini Pulau Batam, Pulau Bintan, dan Pulau Karimun. Metode penelitian yang digunakan dalam penelitian ini adalah penelitian deskriptif kualitatif. Penelitian ini dikondisikan sebagai penelitian kualitatif melalui strategi studi kasus. Sistem pendekatan yang digunakan juga merupakan pendekatan deskriptif analitik. Melakukan pengamatan langsung, mengumpulkan data-data kemudian menghubungkannya dengan kajian teori yang digunakan. Lokus penelitian ini terdapat di Kepulauan Riau dengan melihat pengaruh modal sosial pada perkembangan pariwisata di ketiga pulau yaitu Pulau Batam, Pulau Bintan dan Pulau Karimun. Berdasarkan hasil survey yang saya lakukan di Kepulauan Riau, terutama pada ketiga pulau yaitu Pulau Batam, Pulau Bintan, dan Pulau Karimun, dari ketiga pulau tersebut ternyata pada Pulau Karimun perkembangan pariwisatanya tidak terlalu berkembang karena masyarakat yang tidak menerima adanya wisatawan terutama wisatawan mancanegara. Riau Islands is a province consisting of several islands including Batam Island, Bintan Island and Karimun Island. Social capital is a set of informal values ​​and norms that are owned by community groups in building cooperation. The scope of research in this discussion is focused on the influence of social capital on the development of tourism in the Riau Islands, in this case Batam Island, Bintan Island, and Karimun Island. The research method used in this research is descriptive qualitative research. This research is conditioned as qualitative research through a case study strategy. The system approach used is also a descriptive analytic approach. Make direct observations, collect data and then relate it to the study of the theories used. The locus of this research is in the Riau Islands by looking at the influence of social capital on the development of tourism in the three islands, namely Batam Island, Bintan Island and Karimun Island. Based on the results of a survey I conducted in the Riau Islands, especially on the three islands, namely Batam Island, Bintan Island, and Karimun Island, of the three islands, it turns out that on Karimun Island the development of tourism is not very developed because people do not accept tourists, especially foreign tourists.

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