Long-term investigation of a deep-seated creeping landslide in crystalline rock. Part I. Geological and hydromechanical factors controlling the Campo Vallemaggia landslide

2007 ◽  
Vol 44 (10) ◽  
pp. 1157-1180 ◽  
Author(s):  
L. Bonzanigo ◽  
E. Eberhardt ◽  
S. Loew
Keyword(s):  
Complex Structure ◽  
Companion Paper ◽  
Crystalline Rock ◽  
Fault Zones ◽  
Swiss Alps ◽  
Mitigation Measures ◽  
Metamorphic Rocks ◽  
Artesian Water ◽  
Creep Deformations

Slope movements of the deep-seated Campo Vallemaggia landslide in the southern Swiss Alps have been reported for over 200 years. Surface and borehole investigations of the unstable mass reveal an up to 300 m deep complex structure incorporating 800 million cubic metres of disturbed metamorphic rocks divided into blocks along primary fault zones. An average slide velocity of approximately 5 cm/year can be calculated from various monitoring data recorded between 1892 and 1995. Block movements primarily involve mechanisms relating to multiple shear surfaces, but in cases where slide blocks are constrained by other blocks, creep deformations are observed. Borehole investigations revealed the presence of artesian water pressures, which when integrated with inclinometer and surface geodetic data, helped to provide key insights into the underlying instability mechanisms. This paper reports the findings of an extensive mapping, geophysical, and monitoring investigation carried out over a 20 year period. Results from the analysis are presented with respect to the hydromechanical factors controlling the unstable mass, the significance of which were instrumental in resolving conflicts with regards to the slope mitigation measures required to stabilize the slope. In Part II (see companion paper, this issue), the stabilization works performed at Campo Vallemaggia and their effectiveness are presented.

Long-term investigation of a deep-seated creeping landslide in crystalline rock. Part II. Mitigation measures and numerical modelling of deep drainage at Campo Vallemaggia

2007 ◽  
Vol 44 (10) ◽  
pp. 1181-1199 ◽  
Author(s):  
E. Eberhardt ◽  
L. Bonzanigo ◽  
S. Loew
Keyword(s):  
Numerical Modelling ◽  
Distinct Element ◽  
Companion Paper ◽  
Crystalline Rock ◽  
Swiss Alps ◽  
Mitigation Measures ◽  
Extensive Investigation ◽  
Deep Drainage ◽  
Measured Response

For more than 200 years, the villages of Campo Vallemaggia and Cimalmotto have been slowly moving on top of a deep-seated landslide in the southern Swiss Alps. Numerous mitigation measures have been carried out during this time to stabilize the landslide but with limited to no success. Those attempts largely focussed on minimizing erosion at the toe of the landslide. More recently, the need to stabilize the slope began to intensify, as with each passing year the two villages were being pushed closer to the edge of a 100 m high erosion front at the foot of the landslide. This led to an extensive investigation and monitoring campaign to better understand the factors controlling the landslide movements, which as reported in Part I (see companion paper, this issue), pointed to high artesian pore pressures as being the primary destabilizing mechanism. Here in Part II, the arguments supporting the need for a deep drainage solution are reported, as is the history, implementation, and measured response of the Campo Vallemaggia landslide to the various mitigative measures taken. Numerical modelling results are also presented, based on hydromechanically coupled distinct-element models, to help demonstrate why deep drainage succeeded where other mitigation measures failed.

Masonry: the brittle or plastic material?

2019 ◽  
pp. 22-28
Keyword(s):  
Plastic Material ◽  
Experimental Studies ◽  
Point Of View ◽  
Plastic Properties ◽  
Plastic Deformations ◽  
Base Materials ◽  
Stress States ◽  
Creep Deformations ◽  
Structural Point

The results of experimental studies of masonry on the action of dynamic and static (short-term and long-term) loads are presented. The possibility of plastic deformations in the masonry is analyzed for different types of force effects. The falsity of the proposed approach to the estimation of the coefficient of plasticity of masonry, taking into account the ratio of elastic and total deformations of the masonry is noted. The study of the works of Soviet scientists revealed that the masonry under the action of seismic loads refers to brittle materials in the complete absence of plastic properties in it in the process of instantaneous application of forces. For the cases of uniaxial and plane stress states of the masonry, data on the coefficient of plasticity obtained from the experiment are presented. On the basis of experimental studies the influence of the strength of the so-called base materials (brick, mortar) on the bearing capacity of the masonry, regardless of the nature of the application of forces and the type of its stress state, is noted. The analysis of works of prof. S. V. Polyakov makes it possible to draw a conclusion that at the long application of the load, characteristic for the masonry are not plastic deformations, but creep deformations. It is shown that the proposals of some authors on the need to reduce the level of adhesion of the mortar to the brick for the masonry erected in earthquake-prone regions in order to improve its plastic properties are erroneous both from the structural point of view and from the point of view of ensuring the seismic resistance of structures. It is noted that the proposal to assess the plasticity of the masonry of ceramic brick walls and large-format ceramic stone with a voidness of more than 20% is incorrect, and does not meet the work of the masonry of hollow material. On the basis of the analysis of a large number of research works it is concluded about the fragile work of masonry.

Progress in Developing Constitutive Equations for Inelastic Design Analysis

1983 ◽  
Vol 105 (3) ◽  
pp. 273-276 ◽  
Author(s):  
C. E. Pugh
Keyword(s):  
Constitutive Equations ◽  
Inelastic Strain ◽  
Short Term ◽  
Inelastic Material ◽  
Fast Breeder Reactors ◽  
Breeder Reactors ◽  
Term Creep ◽  
Inelastic Design ◽  
Creep Deformations

A summary is given of the constitutive equations that have been developed for use in design assessments of elevated temperature components of liquid metal fast breeder reactors. The discussion addresses representations of short-term (plastic) and long-term (creep) inelastic material responses. Attention is given to improved representations of the interactions between plastic and creep deformations. Most of the discussion is in terms of constitutive equations that make use of the concept of separating the total strain into elastic, plastic, and creep portions. Additionally, some discussion is given of progress being made toward establishing design equations based on unified measures of inelastic strain that do not distinguish different strain portions.

Mathematical modeling of fluid movement inside the eyeball during intravitreal injection

2021 ◽  
pp. 106-109
Author(s):  
D.V. Lipatov ◽  
◽  
S.A. Skladchikov ◽  
N.P. Savenkova ◽  
V.V. Novoderezkin ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Residence Time ◽  
Complex Structure ◽  
Posterior Vitreous Detachment ◽  
Vitreous Body ◽  
Complete Removal ◽  
Intravitreal Injections ◽  
The World

Background. The avalanche-like growth of intravitreal injections in the world has significantly increased interest in the hemodynamics of the processes that occur in the eye when a drug is injected into the vitreous cavity. Every year, the number of intravitreally used drugs and promising areas in which they can be used is growing. This also applies to the creation of new combined medicines and the development of drugs with a long-term therapeutic effect. Aims. Create mathematical model of eyeball to evaluate the movement of the drug substance in it; to estimate the time of the drug's presence in the eye cavity before its complete removal, to characterize the ways of its removal from the eye cavity; to assess the significance of posterior vitreous detachment during the time when the drug is present in the eye cavity; to evaluate the effect on the hydrodynamics of the depth of drug administration. Results. When the drug is administered closer to the center of the eyeball, its residence time increases in comparison with the parietal administration. With a complete posterior detachment of the vitreous body, the time of finding the drug in the eye is prolonged compared to its absence. The obtained results of mathematical modeling of the movement of the drug administered intravitreally cannot be mechanically transferred to the human eye, due to the more complex structure of the latter. Key words: intravitreal injections, vitreous body, mathematic computing.

Projecting conflict risk following the Shared Socioeconomic pathways: what role for water stress and climate?

2021 ◽  
Author(s):  
Sophie de Bruin ◽  
Jannis Hoch ◽  
Nina von Uexkull ◽  
Halvard Buhaug ◽  
Nico Wanders
Keyword(s):  
Climate Change ◽  
At Risk ◽  
Machine Learning Techniques ◽  
Mitigation Measures ◽  
Related Factors ◽  
Socioeconomic Impacts ◽  
Learning Techniques ◽  
The Future ◽  
Conflict Risk

<p>The socioeconomic impacts of changes in climate-related and hydrology-related factors are increasingly acknowledged to affect the on-set of violent conflict. Full consensus upon the general mechanisms linking these factors with conflict is, however, still limited. The absence of full understanding of the non-linearities between all components and the lack of sufficient data make it therefore hard to address violent conflict risk on the long-term. </p><p>Although it is neither desirable nor feasible to make exact predictions, projections are a viable means to provide insights into potential future conflict risks and uncertainties thereof. Hence, making different projections is a legitimate way to deal with and understand these uncertainties, since the construction of diverse scenarios delivers insights into possible realizations of the future.  </p><p>Through machine learning techniques, we (re)assess the major drivers of conflict for the current situation in Africa, which are then applied to project the regions-at-risk following different scenarios. The model shows to accurately reproduce observed historic patterns leading to a high ROC score of 0.91. We show that socio-economic factors are most dominant when projecting conflicts over the African continent. The projections show that there is an overall reduction in conflict risk as a result of increased economic welfare that offsets the adverse impacts of climate change and hydrologic variables. It must be noted, however, that these projections are based on current relations. In case the relations of drivers and conflict change in the future, the resulting regions-at-risk may change too.   By identifying the most prominent drivers, conflict risk mitigation measures can be tuned more accurately to reduce the direct and indirect consequences of climate change on the population in Africa. As new and improved data becomes available, the model can be updated for more robust projections of conflict risk in Africa under climate change.</p>

scholarly journals On the effect of short-term climate variability on mountain glaciers: insights from a case study

2013 ◽  
Vol 59 (217) ◽  
pp. 992-1006 ◽  
Author(s):  
Daniel Farinotti
Keyword(s):  
Climatic Variability ◽  
Swiss Alps ◽  
Ice Dynamics ◽  
Mountain Glaciers ◽  
Temperature And Precipitation ◽  
Glacier Ice ◽  
Long Term Trends ◽  
Model Set ◽  
Set Up

AbstractStudies addressing the response of glaciers to climate change have so far analyzed the effect of long-term trends in a particular set of meteorological variables only, implicitly assuming an unaltered climatic variability. Here a framework for distinguishing between year-to-year, month-to-month and day-to-day variability is proposed. Synthetically generated temperature and precipitation time series following the same long-term trend but with altered variability are then used to force an ice-dynamics model set up for Rhonegletscher, Swiss Alps. In the case of temperature, variations in the day-to-day variability are shown to have a larger effect than changes at the yearly scale, while in the case of precipitation, variability changes are assessed as having negligible impact. A first set of scenarios is used to show that compared to reference, doubling the temperature variability can reduce glacier ice volume by up to 64% within half a decade. A second set derived from the results of the European ENSEMBLES project, however, shows that such changes are expected to remain below 8% even for extreme scenarios. Although the latter results relativize the importance of the effect in the near future, the analyses indicate that at least caution is required when assuming ‘unchanged variability’.

scholarly journals Addressing fish-passage issues at hydropower and irrigation infrastructure projects in Indonesia

2018 ◽  
Vol 69 (12) ◽  
pp. 1805 ◽  
Author(s):  
Lee J. Baumgartner ◽  
Arif Wibowo
Keyword(s):  
Life History ◽  
Fish Passage ◽  
Mitigation Measures ◽  
Migratory Fish ◽  
Tropical Island ◽  
Life History Stages ◽  
Barrier Effects ◽  
Sumatra Island ◽  
Irrigation Infrastructure

Development activities threaten the long-term sustainability of tropical floodplain systems. The construction of dams, weirs, irrigation infrastructure and regulators affect connectivity among habitats and can facilitate rapid declines in riverine biota, especially fish. Indonesia is a tropical island country with an abundance of monsoonal rivers. Massive expansions in hydropower and irrigation infrastructure are planned over the next two decades and mitigation measures will be needed to protect migratory fish. Most Indonesian freshwater fish need to migrate among habitats to complete essential life-history stages. So, strategies are urgently needed to mitigate the barrier effects of river infrastructure to ensure the long-term sustainability of river fishes. A common tool used worldwide is the construction of upstream and downstream fish passes. Only two fish passes exist in Indonesia. One at Perjaya Irrigation Dam on the Komering River (Sumatra island) and another on Poso Dam on the Poso River (Sulawesi island). Neither of these structures has been assessed and many other projects are proceeding without considering potential impacts on fisheries. The proposed infrastructure upgrades over the next two decades provide a once-in-a-generation opportunity to ensure that migratory fish are adequately protected into the future.

scholarly journals Marmara Island earthquakes, of 1265 and 1935; Turkey

2006 ◽  
Vol 6 (6) ◽  
pp. 999-1006 ◽  
Author(s):  
Y. Altınok ◽  
B. Alpar
Keyword(s):  
Fault Zones ◽  
Marmara Sea ◽  
Sea Waves ◽  
Rock Falls ◽  
The West ◽  
Moderate Size ◽  
Northwestern Turkey ◽  
Earthquake Ruptures ◽  
Fundamental Understanding

Abstract. The long-term seismicity of the Marmara Sea region in northwestern Turkey is relatively well-recorded. Some large and some of the smaller events are clearly associated with fault zones known to be seismically active, which have distinct morphological expressions and have generated damaging earthquakes before and later. Some less common and moderate size earthquakes have occurred in the vicinity of the Marmara Islands in the west Marmara Sea. This paper presents an extended summary of the most important earthquakes that have occurred in 1265 and 1935 and have since been known as the Marmara Island earthquakes. The informative data and the approaches used have therefore the potential of documenting earthquake ruptures of fault segments and may extend the records kept on earthquakes far before known history, rock falls and abnormal sea waves observed during these events, thus improving hazard evaluations and the fundamental understanding of the process of an earthquake.

Deconstructing the Anterior Cruciate Ligament: What We Know and Do Not Know About Function, Material Properties, and Injury Mechanics

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Scott G. McLean ◽  
Kaitlyn F. Mallett ◽  
Ellen M. Arruda
Keyword(s):  
Anterior Cruciate Ligament ◽  
Knee Joint ◽  
Mechanical Response ◽  
Cruciate Ligament ◽  
Complex Structure ◽  
Acute Injury ◽  
Research Attention ◽  
Increased Risk ◽  
Anterior Cruciate

Anterior cruciate ligament (ACL) injury is a common and potentially catastrophic knee joint injury, afflicting a large number of males and particularly females annually. Apart from the obvious acute injury events, it also presents with significant long-term morbidities, in which osteoarthritis (OA) is a frequent and debilitative outcome. With these facts in mind, a vast amount of research has been undertaken over the past five decades geared toward characterizing the structural and mechanical behaviors of the native ACL tissue under various external load applications. While these efforts have afforded important insights, both in terms of understanding treating and rehabilitating ACL injuries; injury rates, their well-established sex-based disparity, and long-term sequelae have endured. In reviewing the expanse of literature conducted to date in this area, this paper identifies important knowledge gaps that contribute directly to this long-standing clinical dilemma. In particular, the following limitations remain. First, minimal data exist that accurately describe native ACL mechanics under the extreme loading rates synonymous with actual injury. Second, current ACL mechanical data are typically derived from isolated and oversimplified strain estimates that fail to adequately capture the true 3D mechanical response of this anatomically complex structure. Third, graft tissues commonly chosen to reconstruct the ruptured ACL are mechanically suboptimal, being overdesigned for stiffness compared to the native tissue. The net result is an increased risk of rerupture and a modified and potentially hazardous habitual joint contact profile. These major limitations appear to warrant explicit research attention moving forward in order to successfully maintain/restore optimal knee joint function and long-term life quality in a large number of otherwise healthy individuals.

scholarly journals On the Statistical Reflection of Long-Term Growth in Agricultural Production

2020 ◽  
Vol 27 (5) ◽  
pp. 36-47
Author(s):  
D. S. Ternovsky ◽  
V. Ya. Uzun
Keyword(s):  
Theoretical Model ◽  
Agricultural Production ◽  
Crop Production ◽  
Complex Structure ◽  
Livestock Production ◽  
Chain Indices ◽  
Statistical Reflection ◽  
The Relationship ◽  
Constant Prices

The article presents the results of a study aimed at proving the existence of systematic error in traditional calculations of long-term growth rates of agricultural production based on chain indices of agricultural production. According to the authors, the article also introduces a more accurate assessment of its dynamics with the account to the structure of the relationship between prices and the volume of agricultural production. The paper describes a theoretical model that is a methodological basis for the study and explains the discrepancy in assessing the dynamics of agricultural production using chain indices and indexes at constant prices. It allows establishing differences in the ratios of the Laspeyres, Paasche, and Lowe indices for crop and livestock production, due to factors in the formation of demand and the complex structure of the relationship between the price level and the volume of production. The adequacy of the constructed theoretical model is proved based on aggregated data that eliminated the influence of incompleteness of the initial information. As a result, it was established that livestock production is characterized by time-distributed changes in prices and quantity of products, which makes it possible to assess its dynamics using both chain indices and symmetric indices. It is proved that the dynamics of crop production cannot be adequately described using chain indices, since a positive correlation of prices of the previous period and production volumes of the current period causes an overstatement of the index in comparable prices of the previous year. Based on calculations within the proposed aggregated model, it is proved that the use of constant prices as the Lowe index weights, updated every five years, is an acceptable approximation of the Fisher symmetric index. Application of the indicated methodology for calculating the index to the data on Russian agricultural production by main types of products in 1990-2018 allowed to establish an overstatement of dynamics by 11.9%. The main difference falls on crop production (+ 19.6%), while for livestock - the differences are insignificant (-0.7%).

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