scholarly journals The contribution of chestnut coppice forests on slope stability in abandoned territory: a case study

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Chiara Bassanelli ◽  
Gian Battista Bischetti ◽  
Enrico Antonio Chiaradia ◽  
Lorenzo Rossi ◽  
Chiara Vergani
Keyword(s):  
Slope Stability ◽  
Root Diameter ◽  
Slope Instability ◽  
Economic Changes ◽  
Sweet Chestnut ◽  
Forestry Practices ◽  
Short Rotation ◽  
Root Cohesion ◽  
Chestnut Coppice ◽  
High Level

Sweet chestnut has been for many centuries fundamental for the Italian mountainous economies, where this kind of forest was traditionally managed in short rotation to rapidly produce wood biomass. Due to the social and economic changes, which made such management scheme unprofitable especially on the steep and remote slopes, such practice has been mainly abandoned and most of chestnut forests became over-aged and very dense, causing an increase of localized slope instability. In this work the effect of over-aged chestnut coppice forests on shallow landslides was analysed by evaluating and comparing mechanical contribution to soil shear strength provided by root systems in differently managed chestnut stands. The study area is located in Valcuvia (Lombardy Prealps) where three different stands, one managed and the others abandoned (over 40 year aged), established on cohesionless slopes (quaternary moraine deposits) were chosen having care to select homogeneous conditions in terms of substrate, aspect and elevation. As slope steepness strongly affects forestry practices and steeper stands are more frequently abandoned, the considered stands have different terrain inclination, 30-35° in abandoned stands and 13° in the managed one. Slope stability of the three sites was evaluated by applying the infinite slope approach accounting for additional root cohesion and tree surcharge. Additional root cohesion was estimated through the Fiber Boundle Model approach by collecting roots in the field and measuring their resistance in laboratory, and by measuring root diameter and density distribution with depth by the wall technique method. The results, as expected, showed that over-aging does not affect root mechanical properties, whereas it significantly affects root distribution within the soil. In terms of slope stability, when steepness exceeds 35°, instability phenomena can be triggered by high level of soil saturation in the case of over-aged forests, whereas for less extreme cases chestnut forests, although over-aged, are able and fundamental to guarantee safe conditions.

scholarly journals Probability Assessment of Slope Instability in Seasonally Cold Regions under Climate Change

2021 ◽  
Author(s):  
Yulong Zhu ◽  
Tatsuya Ishikawa ◽  
Tomohito J. Yamada ◽  
Srikrishnan Siva Subramanian
Keyword(s):  
Climate Change ◽  
Slope Stability ◽  
Water Content ◽  
Air Temperature ◽  
Climate Changes ◽  
Slope Instability ◽  
Climate Factors ◽  
Cold Regions ◽  
The Past ◽  
Assessment Approach

Abstract This paper proposes an effective approach for evaluating the influences of climate change on slope stability in seasonally cold regions. Firstly, to semi-quantitatively assess the effects of climate changes on the uncertainty of climate factors, this study analyzes the trend of the two main climate factors (precipitation and air temperature) by the regression analysis using the meteorological monitoring data of the past 120 years in different scales (e.g., world, country (Japan), and city (Sapporo)), and the meteorological simulation data obtained by downscaling the outputs of three different regional atmospheric models (RAMs) with lateral boundary conditions from three different general circulation models (GCMs). Next, to discuss the effects of different climate factors (air temperature, precipitation, etc.) and to determine the key climate factors on the slope instability, an assessment approach for evaluating the effects of climate changes on slope instability is proposed through the water content simulation and slope stability analysis using a 2-dimensional (2D) finite element method (FEM) homogeneous conceptual slope model with considering freeze-thaw action. Finally, to check the effectiveness of the above assessment approach, assessment of instability of an actual highway embankment slope with the local layer geometry is done by applying the past and predicted future climate data. The results indicate that affected by global warming, the air temperature rise in some cold cities is more serious. The predicted future weather will affect the shape of the normal density curve (NDC) of the distribution of slope failures in one year. The climate changes (especially the increase in precipitation) in the future will increase the infiltration during the Spring season. It will lengthen the time that the highway slope is in an unstable state due to high volumetric water content, thereby enhancing the instability of the slopes and threatening more slopes in the future.

Seismic Coefficients for Simplified Deepwater Slope Stability Assessment Under Earthquake Loading

2021 ◽  
Author(s):  
Aurelian C. Trandafir
Keyword(s):  
Finite Element ◽  
Slope Stability ◽  
Shear Strain ◽  
Limit Equilibrium ◽  
Slope Instability ◽  
Earthquake Loading ◽  
Complex Deformation ◽  
Correlation Relationship ◽  
Stability Analyses ◽  
Seismic Coefficient

Abstract Pseudostatic limit-equilibrium based slope stability analyses are carried out on a routine basis to evaluate stability of submarine slopes under earthquake loading. For slopes in deepwater settings, a major challenge in performing pseudostatic slope stability analyses is selection of an appropriate seismic coefficient. Most published displacement-based methodologies for seismic coefficient selection were developed using simplified sliding block models for seismic slope performance evaluation that are unable to capture the complex deformation mechanism of deepwater slopes during earthquakes. To address this challenge, this study employs two-dimensional dynamic finite-element based deformation analysis to investigate the earthquake response of submarine clay slopes characterized by morphology, stratigraphic architecture and geotechnical properties representative for the deepwater environment. Finite-element computed seismic slope performance indicators, including horizontal peak ground acceleration at the seafloor and earthquake-induced maximum shear strain within the slope, along with horizontal seismic coefficients required to trigger slope instability in limit-equilibrium based pseudostatic stability analyses are used to develop a rational shear strain-based correlation relationship for deepwater slope seismic coefficient selection.

scholarly journals Characteristics of ground motion and threshold values for colluvium slope displacement induced by heavy rainfall: a case study in northern Taiwan

2016 ◽  
Vol 16 (6) ◽  
pp. 1309-1321 ◽  
Author(s):  
Ching-Jiang Jeng ◽  
Dar-Zen Sue
Keyword(s):  
Slope Stability ◽  
Heavy Rainfall ◽  
Slope Failure ◽  
Drainage System ◽  
Threshold Value ◽  
Slope Instability ◽  
Disaster Prevention ◽  
Strain Gages ◽  
Slope Displacement ◽  
Northern Taiwan

Abstract. The Huafan University campus is located in the Ta-lun Shan area in northern Taiwan, which is characterized by a dip slope covered by colluvium soil of various depths. For slope disaster prevention, a monitoring system was constructed that consisted of inclinometers, tiltmeters, crack gages, groundwater level observation wells, settlement and displacement observation marks, rebar strain gages, concrete strain gages, and rain gages. The monitoring data derived from hundreds of settlement and displacement observation marks were analyzed and compared with the displacement recorded by inclinometers. The analysis results revealed that the maximum settlement and displacement were concentrated on the areas around the Hui-Tsui, Zhi-An, and Wu-Ming buildings and coincided with periods of heavy rainfall. The computer program STABL was applied for slope stability analysis and modeling of slope failure. For prevention of slope instability, a drainage system and tieback anchors with additional stability measures were proposed to discharge excess groundwater following rainfall. Finally, threshold value curves of rainfall based on slope displacement were proposed. The curves can be applied for predicting slope stability when typhoons are expected to bring heavy rainfall and should be significant in slope disaster prevention.

Software Agents in Today's Digital Economy

2001 ◽  
pp. 88-100 ◽  
Author(s):  
Mahesh S. Raisinghani
Keyword(s):  
Intelligent Agents ◽  
New Technology ◽  
Software Agents ◽  
Information Filtering ◽  
Intelligent Agent ◽  
Social Dimension ◽  
Economic Changes ◽  
Software Products ◽  
Intelligent Software Agents ◽  
High Level

One of the most discussed topics in the information systems literature today is software agent/intelligent agent technology. Software agents are high-level software abstractions with inherent capabilities for communication, decision making, control, and autonomy. They are programs that perform functions such as information gathering, information filtering, or mediation (running in the background) on behalf of a person or entity. They have several aliases such as agents, bots, chatterbots, databots, intellibots, and intelligent software agents/robots. They provide a powerful mechanism to address complex software engineering problems such as abstraction, encapsulation, modularity, reusability, concurrency, and distributed operations. Much research has been devoted to this topic, and more and more new software products billed as having intelligent agent functionality are being introduced on the market every day. The research that is being done, however, does not wholeheartedly endorse this trend. The current research into intelligent agent software technology can be divided into two main areas: technological and social. The latter area is particularly important since, in the excitement of new and emergent technology, people often forget to examine what impact the new technology will have on people’s lives. In fact, the social dimension of all technology is the driving force and most important consideration of technology itself. This chapter presents a socio-technical perspective on intelligent agents and proposes a framework based on the data lifecycle and knowledge discovery using intelligent agents. One of the key ideas of this chapter is best stated by Peter F. Drucker in Management Challenges for the 21st Century when he suggests that in this period of profound social and economic changes, managers should focus on the meaning of information, not the technology that collects it.

scholarly journals Shaping of personality of Russian youngsters during the pre-perestroika and post-perestroika periods of development of society

2018 ◽  
Vol 51 ◽  
pp. 01005
Author(s):  
Vladimir Uryvaev ◽  
Larisa Subbotina ◽  
Anatoliy Karpov ◽  
Ivan Senin ◽  
Aleksandr Karpov
Keyword(s):  
Self Regulation ◽  
General Medicine ◽  
Personal Characteristics ◽  
Psychological Adaptation ◽  
General Level ◽  
Russian Society ◽  
Economic Changes ◽  
Voluntary Regulation ◽  
Self Actualization ◽  
High Level

Introduction – socio-political and socio-economic changes in society largely define a developing personality. Goal – to conduct a psycho-diagnostic evaluation of the changes in basic personal characteristics of young students in the context of Russian society development. Results: the comparison of two groups of medical student (both groups are identical: the second course, the department of general medicine, Yaroslavl State Medical University). Testing of 1992 (n = 243) and 2016 (n = 197) using the 16-PF Questionnaire and the POI reveals two main tendencies. The first tendency is the increase of the general level of tension (the 16-PF scales: C, I, O, Q4 – all the quantitative indices have increased, p < 0.01, Student's t-test). The second tendency is a significant growth of the efficiency of personal characteristics providing self-regulation and voluntary behaviour (the 16-PF scales: E, G, H, Q3 are analogous to the first tendency; the SAV scale of the POI also reports a growth with high statistical values). Discussion: the respondents from the first group were born in 1972–1973. Prenatal maturation, babyhood, junior school, and early adolescent age took place in the epoch of a high degree of stability and succession in the development of society. The respondents from the second group were born in 1998–1999. The samples are separated by a generation. The second group (2016 testing) reports a high level of neuro-psychic tension during socio-psychological adaptation and, consequently, the growth of efforts in developing voluntary regulation of social behavior. Evidently, there is value of self-actualization in the new reality.

scholarly journals Safety Assessment of Tunnel Portals for Site Selection Based on Spatial Information Geoprocessing

2019 ◽  
Vol 4 (4) ◽  
pp. 70
Author(s):  
Iau-Teh Wang
Keyword(s):  
Information Technology ◽  
Slope Stability ◽  
Site Selection ◽  
Spatial Information ◽  
Slope Instability ◽  
Geographical Information ◽  
Site Evaluation ◽  
The Stability ◽  
Slice Method ◽  
Spatial Information Technology

The evaluation of portal locations for mountain tunnels is among the most crucial considerations during route selection and structural layout planning. The development of spatial information technology has provided a more objective approach for assessing the slope stability of potential portal sites. The simulations in such studies have been performed to evaluate potential hazards and slope stability. However, potential instabilities resulting from excavation are seldom considered in these studies. Therefore, a method based on spatial information technology was developed in this study for considering the potential impact of the direction and depth of excavations on portal stability. An analysis method for an infinite slope was integrated into the geographical information system for evaluating the stability of critical wedges. The proposed method provides a reasonable estimation comparable with that provided by the conventional slice method. The results of applying this method to six mountain tunnel portals where slope instability occurred during construction indicate that the actual outcomes agreed with the predicted outcomes. For potential portal site evaluation, the proposed method facilitates the rapid estimation of safety factors for various slope designations, which is useful for site selection.

Development of a dynamic growth model for sweet chestnut coppice: A case study in Northwest Spain

2019 ◽  
Vol 409 ◽  
pp. 108761
Author(s):  
Marta Prada ◽  
Marta González-García ◽  
Juan Majada ◽  
Celia Martínez-Alonso
Keyword(s):  
Growth Model ◽  
Sweet Chestnut ◽  
Dynamic Growth ◽  
Chestnut Coppice

Study on Slope Instability Disciplinarian on the Condition of Rainfall

2013 ◽  
Vol 353-356 ◽  
pp. 654-658
Author(s):  
Nan Tong Zhang ◽  
Xiao Chun Zhang ◽  
Hua Rong Wang ◽  
Chen Yan
Keyword(s):  
Slope Stability ◽  
Tensile Stress ◽  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Road Construction ◽  
Slope Instability ◽  
Slope Surface ◽  
Large Area ◽  
Break Zone

Slope stability is one of the problems of road construction which should be faced with and solve. Rainfall can reduce the shear strength of slope soil and raise the underground water level which can lead to increase slope soil pore water pressure. The influence of rainfall infiltration on slop is mainly to change the slope seepage field, increase dynamic and hydrostatic water load on the slope soil and decrease of soil shear parameters. More abundant rainfall of typhoon area could make the road slope stability more fragile. Based on Matoushan Mountain along 104 state roads in Taizhou city, Zhejiang province, slope instability disciplinarian on the condition of rainfall is studied using the method of numerical simulation in this paper. As the results, when the rainfall intensity was 0.006 m/h and continuous rain was in 24 hours, the slope surface compressive stress tends to zero which began to appear tensile stress area on the condition of self-weight. And when the rainfall intensity was 0.01 m/h and continuous rain was in 24 hours, the large area of the slope surface was tensile stress area which means to appear break zone in slope surface and likely to landslide at the same time.

The Records of Slope Reinforcement Engineering in a Loess City

2012 ◽  
Vol 226-228 ◽  
pp. 1365-1370
Author(s):  
Qi Xia Liu ◽  
Liang Fan
Keyword(s):  
Slope Stability ◽  
Good Practice ◽  
Stability Study ◽  
Practice Effect ◽  
Slope Instability ◽  
Loess Landslide ◽  
Loess Area ◽  
Loess Slope ◽  
Geological Conditions ◽  
Reinforcement Measures

This article selected a typical loess slope engineering as the research object, and through the characteristics of loess landslide, landslide environmental geological conditions, the formation mechanism of the landslide study of the loess area of urban slope instability factors, loess slope stability of the calculation method and reinforcement measures. This paper adopts the theory of Morgenstern-Price to analyzing the stability of the slope, referencing with Sweden finite slice method, Simplified Bishop method, Simplify Janbu method. The reinforcement adopts the technology of possessed anchor to disposing the loess slope, and has good Practice effect. The loess slope stability study area has a large reference.

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