scholarly journals Assessment of slope stability at landslide area in B’LaoWard, Bao Loc city, Lam Dong province and solutions to prevent landslide

2016 ◽  
Vol 19 (1) ◽  
pp. 76-85 ◽  
Author(s):  
Vinh Trong Bui ◽  
Ha Sanh Nguyen ◽  
Thong Huynh Nguyen
Keyword(s):  
Slope Stability ◽  
Rainy Season ◽  
Factor Of Safety ◽  
Present Model ◽  
Mountainous Terrain ◽  
Landslide Area ◽  
Soil Extraction ◽  
Two Cities ◽  
The Relationship ◽  
Moisture Increase

Bao Loc is one of two cities of Lam Dong province. Located on Di Linh – Bao Loc plateau about 800 – 1000m elevation, Bao Lọc has the complex mountainous terrain. The authors have surveyed and collected information and samples in the landslide area. This area occurred the cracks, damaged several buildings within 1.2 ha. The authors have also identified causes of landslide such as geomorphotogy, stratigraphic slope, slope materials, hydrogeology, climate, etc. However, the main cause was soil extraction activities at toe of slope which lost the counterweight berm, associated with the moisture increase of soil due to heavy rainfall in rainy season. It reduced the shear strength of slope materials. Based on data analysis of surveyed location, the authors applied GeoStudio software by SLOPE/W module so as to calculate the slope stability under the sections. Analyzed results showed that the slope was stable in dry season with the minimum factor of safety (FS) around 1.474, in rainy season the slope was unstable with minimum the factor of safety around 0.896 commensurate with groundwater present model. The minimum factors of safety in the model with the appearance of groundwater table are represented by the distance among the slope sections following the relationship function with correlation coefficient (R2) is 0.9915. According to the interpolated result from the relationship function showed that the width of unstable area or the width of sliding mass is 35.1m. As the obtained results, the authors proposed realizable solutions to stabilize the slope in order to minimize the effect of landslide at the study area.

scholarly journals Perencanaan Perkuatan Lereng Menggunakan Geoframe di Jalan Raya Dampit-Lumajang

2022 ◽  
Vol 10 (1) ◽  
pp. 59-68
Author(s):  
Lafridha Alyazahari ◽  
Luthfi Amri Wicaksono ◽  
Dwi Nurtanto
Keyword(s):  
Slope Stability ◽  
Safety Factor ◽  
Rainy Season ◽  
Factor Of Safety ◽  
Soil Mass ◽  
Soil Stability ◽  
Safe Condition ◽  
Manual Calculation

A Landslide is the movement of soil mass or rock constituents down the slope due to disturbance of soil stability. One of the factors that affect soil stability is the rainy season as happened in Sumberwuluh Village, Candipuro District, Lumajang Regency. The alternative used to stabilize the slope is by changing the slope geometry, then adding geoframe reinforcement. This study aims to determine the value of the factor of safety (SF) of unreinforced slopes, after changing the slope geometry, and after being given geoframe reinforcement. The method used in analyzing slope stability is the Ordinary/Fellenius method. The results of the calculation of slope stability without reinforcement using the Rocscience Slide software obtained a SF of 0.719, while the manual calculation obtained a SF of 0.7191. The two values ​​of the safety factor are less than 1.25, which means that landslides often occur. The results of the calculation of slope stability after changing the geometry of the slopes obtained a SF of 0.828 where the value is less than 1.25 which means that landslides often occur. The slopes that have been changed geometry are added with geoframe reinforcement. The results of the calculation of slope stability using geoframe reinforcement obtained a SF of 1.315 where the value is more than 1.25 which means that landslides are rare or slope in a safe condition.

scholarly journals Analysis of Slope Stability for Kaande Landslide of Phewa Watershed, Pokhara, Nepal

2020 ◽  
Vol 2 (1) ◽  
pp. 11-21
Author(s):  
Keshav Basnet ◽  
Dhruba Wagle ◽  
Sagar Bhattarai ◽  
Biwas Babu Sadadev
Keyword(s):  
Soil Erosion ◽  
Slope Stability ◽  
Factor Of Safety ◽  
Source Zone ◽  
Coarse Grained ◽  
Mitigation Measures ◽  
Sieve Analysis ◽  
Landslide Area ◽  
Slope Stabilization ◽  
Bio Engineering

 Phewa watershed of Kaski, Nepal is constantly facing landslides and soil erosion problems. Andheri Khola sub-basin of Phewa watershed accounts the maximum amount of sediment inflow into Phewa Lake. Therefore Kaande Landslide of Andheri Khola sub-basin, located between Deurali and Paundur villages at the source zone of Andheri Khola is chosen for the slope stabilization to control the sediment flow. The main objective of the study was to analyze the slope stability condition of the landslide area for which the whole landslide area was divided into eight zones starting from the crown to the toe based on the major parameters like soil/rock type, slope inclination, spring source and surface water on the basis of field observation. The factor of safety of each zone was calculated based on stability analysis of an infinite slope of cohesive soils. Sieve analysis result shows the landslide area has coarse grained structure (gravel and sand) dominant. The factor of safety of the landslide was found to be from 0.281 to 0.710. The field assessment and factor of safety reveals the Kaande landslide to be unstable and further possibilities of landslides and soil erosion in the future. For mitigating the hazard, eco-friendly soil bio-engineering measures such as direct seeding of grasses/shrubs, grasses/shrubs/trees plantation, brush layering, and gabion wire bolster cylinders are recommended for slope stabilization based on the optimal techniques guidelines of Mercy Corps Nepal, 2014. It is recommended to apply the proposed mitigation measures as early as possible to prevent the further landslide hazard.

scholarly journals Comparison of factor of safety using different method of analysis for slope stability

2021 ◽  
Vol 1 (1) ◽  
pp. 52-58
Author(s):  
Norfarah Nadia Ismail ◽  
Ahmad Bukhari Ramli ◽  
Siti Noorliyana Mohd Pami
Keyword(s):  
Slope Stability ◽  
Shear Force ◽  
Factor Of Safety ◽  
Simplified Method ◽  
Critical Slope ◽  
The Stability ◽  
The Relationship ◽  
Manual Calculation ◽  
Ideal Method ◽  
The Ideal

Currently, the construction of slope is increasing, thus, the risk of slope to fail also increase. The series of landslide happen to the man-made slope has been recorded since in the early of 1993 until now. Many efforts such as treating the critical slope, redesigned the failed slope, and analyze the stability of the slope have been done. However, the landslide is still happening in Malaysia. The factor of safety (FOS) from the stability analysis that has been used might not be adequate to determine the safety of the slope in Malaysia. Therefore, in this study, the optimum factor of safety is obtained by using three methods of slice, Bishop’s Simplified method, Spencer method, and Morgenstern-Price method which have been used in many projects. A study place is selected in Ladang Balau, Semenyih, in Selangor and from the CIU test, the important soil parameter for slope is extracted for analysis of slope stability using SLOPE/W and manual calculation. The lambda for Spencer method and Morgenstern-Price method was generated for further discussion on the relationship between lambda and factor of safety. The data generated from both calculation method, from manual and software, were discussed and next the ideal method to achieve the optimum factor of safety determined. The factor of safety for every method basically are influenced by the interslice shear force presence but not Bishop’s Simplified method as moment equilibrium is insensitive towards interslice force function. For lambda, the factor that influenced the value is the function used; constant and half-sine function, however, for Bishop’s Simplified method, the lambda is equal to zero as the method ignored the interslice shear force. The Morgenstern-Price method has been chosen to be the best method to generate a good factor of safety.

Optimization Fuzzy Inference System based Particle Swarm Optimization for Onset Prediction of the Rainy Season

2020 ◽  
pp. 61-70
Author(s):  
Noviandi Noviandi ◽  
Ahmad Ilham
Keyword(s):  
Particle Swarm Optimization ◽  
Fuzzy Inference System ◽  
Rainy Season ◽  
Fuzzy Inference ◽  
Sea Surface ◽  
Good Work ◽  
Swarm Optimization ◽  
Inference System ◽  
Coefficient Corrélation ◽  
The Relationship

Rainfall which is occurred in an area explain the Onset Rainy Season (ORS). ORS is a characteristic of the rainy season which is important to know, but the characteristics of the rain itself is very difficult to predict. We use the method of Fuzzy Inference System (FIS) to predict ORS. Unfortunately, FIS is weak to determine parameters so that influences the working FIS method. In this study, we use PSO to optimize parameter of the FIS method to increase perform of the FIS method for onset prediction of the rainy season with the predictor Sea Surface Temperature Nino 3.4 and Index Ocean Dipole. We used coefficient correlation to determine the relationship between two variables as predictors and RMSE as evaluate to all methods. The experiment result has shown that the work of FIS-PSO after optimizing produced the good work with the coefficient correlation = 0.57 and RMSE = 2.96 that is the smallest value that is better performance if compared with other methods. It can be concluded that the method proposed can increase the onset prediction of the rainy season.

scholarly journals The Mediating Effect of Marital Intimacy on the Relationship between Spouse-Related Stress and Prenatal Depression in Pregnant Couples: An Actor–Partner Interdependent Model Test

2021 ◽  
Vol 18 (2) ◽  
pp. 487
Author(s):  
Miyoung Lee ◽  
Yeon-Suk Kim ◽  
Mi-Kyoung Lee
Keyword(s):  
Mediating Effect ◽  
Prenatal Depression ◽  
Mediating Effects ◽  
Factors Affecting ◽  
Marital Intimacy ◽  
Paternal Factors ◽  
Two Cities ◽  
Related Stress ◽  
The Relationship ◽  
Structured Questionnaire

Prenatal depression is an important factor in predicting postpartum depression. Most studies have assessed factors affecting prenatal depression by focusing on pregnant wives. However, the emotional and psychological aspects of both expectant parents need to be considered. Therefore, the purpose of this study was to examine the effect of spouse-related stress in expectant couples on prenatal depression and investigate the mediating effects of marital intimacy on this relationship. A total of 120 expectant couples from two cities in Korea at more than 15 weeks of completed pregnancy participated in the study. Using a structured questionnaire, we assessed the general characteristics of the participants, spouse-related stress, prenatal depression, and marital intimacy. The results revealed that four actor effects and one partner effect were significant. Marital intimacy and prenatal depression among expectant parents were affected by spouse-related stress. Moreover, spouse-related stress in the husbands completely mediated marital intimacy in pregnant wives, demonstrating partner effects on prenatal depression in pregnant wives. Therefore, it was observed that paternal factors affect prenatal depression in pregnant wives. This warrants the inclusion of husbands in marital interventions and strategies to improve marital intimacy in pregnant wives.

A realistic model for transverse shear stiffness prediction of composite corrugated-core sandwich structure with bonding effect

2021 ◽  
pp. 109963622199386
Author(s):  
Tianshu Wang ◽  
Licheng Guo
Keyword(s):  
Present Model ◽  
Shear Stiffness ◽  
Realistic Model ◽  
Torsional Stiffness ◽  
Fem Model ◽  
The Core ◽  
Bonding Effect ◽  
Stiffness Model ◽  
Bonding Area ◽  
The Relationship

In this paper, a shear stiffness model for corrugated-core sandwich structures is proposed. The bonding area is discussed independently. The core is thought to be hinged on the skins with torsional stiffness. The analytical model was verified by FEM solution. Compared with the previous studies, the new model can predict the valley point of the shear stiffness at which the relationship between the shear stiffness and the angle of the core changes from negative correlation to positive correlation. The valley point increases when the core becomes stronger. For the structure with a angle of the core smaller than counterpart for the valley point, the existing analytical formulations may significantly underestimate the shear stiffness of the structure with strong skins. The results obtained by some previous models may be only 10 persent of that of the present model, which is supported by the FEM model.

scholarly journals Description of the larva of Bromeliagrion rehni (Odonata: Coenagrionidae) with bionomic notes concerning its phytotelmic habitat in central Amazonas, Brazil

2008 ◽  
Vol 25 (3) ◽  
pp. 479-486 ◽  
Author(s):  
Sharlene R. da S. Torreias ◽  
Ulisses G. Neiss ◽  
Neusa Hamada ◽  
Ruth L. Ferreira-Keppler ◽  
Frederico A.A. Lencioni
Keyword(s):  
Rainy Season ◽  
Environmental Parameters ◽  
Dry Season ◽  
Stage Larva ◽  
Water Volume ◽  
Apical Region ◽  
Last Stage ◽  
First Time ◽  
The Relationship

The last-stage larva of Bromeliagrion rehni Garrison in De Marmels & Garrison, 2005 is described and illustrated and bionomics and habitat information on this species are provided. The study was conducted in the Reserva Florestal Adolpho Ducke, located near Manaus, state of Amazonas, Brazil.Twelve samplings were done between April, 2003 and April, 2005: six in the rainy season and six in the dry season. In each sampling month, 12 bromeliads (Guzmania brasiliensis Ule, 1907, Bromeliaceae) were collected, six of which were terrestrial and six epiphytic, yielding144 samples. A total of 75 specimens of B. rehni were collected. The relationship between larval B. rehni abundance and the measured environmental parameters (volume (ml), pH, season and stratum) was significant (ANCOVA, F = 5.296, d.f. = 130, p < 0.001). Larvae were most abundant in the rainy season (p < 0.01) and water volume was positively related to the abundance of B. rehni. Larvae of B. rehni can be distinguished from those of B. fernandezianum (the only species in the genus with described larvae) by the number of setae in the prementum and by the color of the apical region of the femur. The association of this species with phytotelmata of G. brasiliensis is reported here for the first time.

scholarly journals Structure of pond vegetation of a vereda in the Brazilian Cerrado

Rodriguésia ◽  
2011 ◽  
Vol 62 (4) ◽  
pp. 721-729 ◽  
Author(s):  
Suzana Neves Moreira ◽  
Arnildo Pott ◽  
Vali Joana Pott ◽  
Geraldo Alves Damasceno-Junior
Keyword(s):  
Water Depth ◽  
Rainy Season ◽  
Life Form ◽  
Mato Grosso ◽  
Relative Cover ◽  
Dry Seasons ◽  
The Relationship ◽  
Measured Water ◽  
Mato Grosso Do Sul ◽  
New Occurrences

Abstract This is the first report on aquatic macrophytes in ponds of veredas (palm swamps) in the Cerrado (Brazilian savanna). We studied a pond in a vereda in Terenos, Mato Grosso do Sul state, central-western Brazil, during drought and flood periods to assess plant community structure and the relationship between species distribution and water depth. Sampling was carried out in five permanent transects, along which we placed sampling units of 1 m2 quadrats every 5 m. We estimated visually the relative cover of each species, bare ground, dead matter, and exposed water. We also measured water depth. We recorded 77 species of 49 genera and 31 families. The number of species varied between seasons, and in the rainy season the amphibious life form was predominant. The richest families were Poaceae (15 species), Cyperaceae (11), Asteraceae (4) and Lentibulariaceae (4). The richest genera were Rhynchospora (4), Utricularia (4), Eleocharis (4), Aeschynomene (3), Bacopa (3), Ludwigia (3) and Panicum (3). We found six new occurrences for the cerrado. Eleocharis acutangula had the highest relative cover (rainy and dry seasons), followed by Bacopa reflexa (rainy season), Paspalum lenticulare (rainy and dry seasons), Leersia hexandra (rainy and dry seasons), and Sagittaria rhombifolia (rainy season). Some species were distributed mainly at shallower depths, others occurred in deeper water, whereas some species varied greatly in terms of depth. Heliotropium filiforme and Ludwigia nervosa were found only in the dry season. In the rainy season, as expected, the exclusive species were mostly true aquatics.

Some difficulties associated with the limit equilibrium method of slices

1983 ◽  
Vol 20 (4) ◽  
pp. 661-672 ◽  
Author(s):  
R. K. H. Ching ◽  
D. G. Fredlund
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Stability Limit ◽  
Limit Equilibrium Method ◽  
Soil Conditions ◽  
Side Force ◽  
Limit Equilibrium Methods ◽  
Equilibrium Method ◽  
The Stability

Several commonly encountered problems associated with the limit equilibrium methods of slices are discussed. These problems are primarily related to the assumptions used to render the inherently indeterminate analysis determinate. When these problems occur in the stability computations, unreasonable solutions are often obtained. It appears that problems occur mainly in situations where the assumption to render the analysis determinate seriously departs from realistic soil conditions. These problems should not, in general, discourage the use of the method of slices. Example problems are presented to illustrate these difficulties and suggestions are proposed to resolve these problems. Keywords: slope stability, limit equilibrium, method of slices, factor of safety, side force function.

Stable Isotopes Analysis of Precipitation in Subtropical Plateau of Yunnan

2014 ◽  
Vol 1010-1012 ◽  
pp. 1059-1063
Author(s):  
Wei Guan ◽  
Tao Fan ◽  
Xiu Qin Zhu
Keyword(s):  
Stable Isotopes ◽  
Rainy Season ◽  
Mean Value ◽  
Dry Season ◽  
Precipitation Line ◽  
Stable Isotopic ◽  
Different Seasons ◽  
Geographical Position ◽  
The Mean ◽  
The Relationship

To elucidate the relationship between stable isotopes of precipitation (SIP) and the extreme drought in Kunming area, based on the stable isotopes data of the GNIP in Kunming site from 1986 to 2003, the precipitation line equation is brought forward and the seasonal change rule of stable isotopes are discussed. The stable isotopic compositions of precipitation exhibit great diversities in different seasons during to influences of multiple factors, such as monsoon, rainfall amount moisture source and others. The δ18O values in rainwater exhibit significant seasonal variations, the average of-10.12‰ in rainy season, the dry season is-4.5‰, having lower values in the rainy season and higher one in the dry season. The amount effect of precipitation is very distinct, that concealed the temperature effect. Got the special geographical position,dvalues present unique characteristics, the average ofdvalues is 10.78‰ in rainy season, and is 4.86‰ in dry season, the mean value is generally lower than most parts of the world.

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