Interslice force functions for computing active and passive earth force

1999 ◽  
Vol 36 (6) ◽  
pp. 1015-1029 ◽  
Author(s):  
Noshin Zakerzadeh ◽  
D G Fredlund ◽  
D E Pufahl
Keyword(s):  
Slip Surface ◽  
Limit Equilibrium ◽  
Retaining Wall ◽  
Vertical Wall ◽  
Force Function ◽  
Classical Solutions ◽  
End Point ◽  
Starting Point ◽  
General Limit ◽  
Selection Of

Recent methods to calculate the lateral earth force on a retaining wall have involved the method of slices and limit equilibrium concepts. An important issue in formulating the solution is the selection of an appropriate interslice force function (i.e., the ratio of the shear force to the normal force of vertical slices along the slip surface). This paper proposes interslice force functions that can be used to compute the active and passive earth forces in conjunction with the limit equilibrium method. An example problem involving a vertical wall with a horizontal backslope is analyzed using the general limit equilibrium (GLE) method and the proposed interslice force functions. The procedure recommended to compute the lateral earth force and the point of application of the force is outlined. The computed lateral earth forces, and the point of application, are compared with those from the classical solutions. For the active case, reasonable results were obtained when using an interslice force function that varies linearly from the starting point of the slip surface (at some distance from the wall) to the end point of the slip surface (adjacent to the wall). For the passive case, reasonable results were obtained when using an interslice force function that remains at zero from the starting point of the slip surface (at some distance from the wall) to the midpoint of the slip surface and then varies linearly from the midpoint of the slip surface to the end point of the slip surface (adjacent to the wall).

General limit equilibrium method for lateral earth force

1984 ◽  
Vol 21 (1) ◽  
pp. 166-175 ◽  
Author(s):  
Harianto Rahardjo ◽  
Delwyn G. Fredlund
Keyword(s):  
Shear Strength ◽  
Slip Surface ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Vertical Wall ◽  
Limit Equilibrium Method ◽  
External Loading ◽  
Equilibrium Method ◽  
General Limit

The calculation of the lateral earth force using the limit equilibrium method of slices is an indeterminate problem. An assumption regarding the direction or the magnitude of certain forces, or the position of the line of thrust can be used to render the problem determinate.A general formulation for the lateral earth force is derived in accordance with the assumptions involved in the general limit equilibrium (GLE) method. An assumption concerning a direction of the interslice forces is utilized to solve the problem of indeterminancy. Horizontal force equilibrium conditions within a sliding mass are used to compute the magnitude of the active and passive forces. The point of application of the lateral earth force is obtained by considering moment equilibrium for each slice.The coefficient of lateral earth force obtained from the GLE method agrees closely with the results obtained from most other theories. Comparisons are made to the Coulomb theory (i.e., using a planar slip surface) and other theories using a curved or a composite slip surface.Data are presented for the case of a horizontal cohesionless backfill against a vertical wall. The lateral earth force can be contoured on the grid of centers of rotation. These contours have a bell-shaped characteristic and can be used to locate the critical center of rotation.The main advantage of this method lies in its capability to analyze arbitrarily stratified soil deposits with complex geometries. Different conditions of pore-water pressure, shear strength, and external loading can be accommodated in the analysis. Factors of safety greater than 1.0 can be applied to the shear strength of the soil for design purposes. Keywords: lateral earth force, active force, passive force, general limit equilibrium, interslice forces, and coefficient of lateral earth force.

scholarly journals Calculation of Active Earth Pressure for Narrow Backfill with a Curved Slip Surface

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Zhihui Wang ◽  
Aixiang Wu ◽  
Yiming Wang
Keyword(s):  
Equilibrium Equation ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Failure Surface ◽  
Friction Angle ◽  
Force Balance ◽  
Vertical Force ◽  
The Earth

A method was proposed to calculate the earth pressure from a cohesionless backfill with a high aspect ratio (ratio of height to width of retaining wall). An exponential equation of slip surface was proposed first. The proposed nonlinear slip surface equation can be obtained once the width and height of the backfill as well as the internal friction angle of the backfill were given. The failure surface from the proposed formula agreed well with the experimental slip surface. Then, the earth pressure was calculated using a simplified equilibrium equation based on the proposed slip surface. It is assumed that the minor principal stress of the backfill near the wall and at its corresponding slip surface where the depth is the same is the same. Thus, based on the vertical force balance of the horizontal backfill strip, assuming the wall-soil interface and the slip surface is in the limit equilibrium state, defined by the Mohr–Coulomb criterion, the differential equilibrium equation was obtained and numerically solved. The calculated results agreed well with the test data from the published literature.

Effect of the axis of moment equilibrium in slope stability analysis

1992 ◽  
Vol 29 (3) ◽  
pp. 456-465 ◽  
Author(s):  
D. G. Fredlund ◽  
Z. M. Zhang ◽  
L. Lam
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Stability Limit ◽  
Slip Surfaces ◽  
Moment Equilibrium ◽  
Simplified Method ◽  
General Limit ◽  
The Moment

Some of the methods of slices satisfying moment equilibrium derived for circular slip surfaces have been extended to accommodate noncircular (or composite) type slip surfaces. A question arises regarding the point about which moment equilibrium should be taken and whether varying the center for moment equilibrium has a significant effect upon the computed factor of safety. This paper addresses the question of the effect of the center for moment equilibrium as it pertains to noncircular (or composite) slip surfaces. In particular, extensions of the Ordinary, Bishop's simplified, and the General Limit Equilibrium (GLE) methods are examined. The results show that considerable variations in the factor of safety can occur when using the extended Ordinary method. The extended Bishop's simplified method shows varying factors of safety as the moment axis moves vertically. Variations in the computed factor of safety can generally be expected to be less than 12%. The GLE, Morgerstern–Price, and Spencer methods are independent of the axis for moment equilibrium. Key words : slope stability, limit equilibrium, moment equilibrium, factor of safety, noncircular slip surface.

ANALISIS PENANGGULANGAN KELONGSORAN TANAH PADA RUAS JALAN GUNUNG TUGEL PATIKRAJA BANYUMAS

2017 ◽  
Vol 14 (1) ◽  
pp. 53
Author(s):  
Arwan Apriyono ◽  
Sumiyanto Sumiyanto ◽  
Nanang Gunawan Wariyatno
Keyword(s):  
Limit Equilibrium ◽  
Retaining Wall ◽  
Limit Equilibrium Method ◽  
Pile Foundations ◽  
Soil Parameters ◽  
The Road ◽  
Realistic Option ◽  
Stable Conditions ◽  
Using Data ◽  
Wall Slope

Gunung Tugel is an area that located Patikraja Region, Southern Banyumas. Thetopography of the area is mostly mountainous with a slope that varies from flat to steep. Thiscondition makes to many areas of this region potentially landslide. In 2015, a landslideoccurred in Jalan Gunung Tugel. The Landslide occurred along 70 meters on the half of theroad and causing traffic Patikraja-Purwokerto disturbed. To repair the damage of the road andavoid further landslides, necessary to analyze slope stability. This study is to analyze landslidereinforcement that occurred at Gunung Tugel and divides into 3 step. The first step is fieldinvestigation to determine the condition of the location and dimensions of landslides. Thesecond step is to know the soil parameters and analyzes data were obtained from the field. Andthe final step is analyzed of the landslide reinforcement by using data obtained from thepreceding step. In this research, will be applied three variations of reinforcement i.e. retainingwall, pile foundation and combine both of pile foundations and retaining wall. Slope stabilityanalysis was conducted using limit equilibrium method. Based on the analysis conducted onthe three variations reinforcement, combine both of pile foundations and retaining wall morerecommended. Application of and combine both of pile foundations and retaining wall is themost realistic option in consideration of ease of implementation at the field. From thecalculations have been done, in order to achieve stable conditions need retaining wall withdimensions of 2 meters high with 2,5 meters of width. DPT is supported by two piles of eachcross-section with 0.3 meters of diameter along 10 meters with 1-meter in space. Abstrak: Gunung Tugel adalah salah satu daerah yang terletak di Kecamatan PatikrajaKabupaten Banyumas bagian selatan. Kondisi topografi daerah tersebut sebagian besar berupapegunungan dengan kemiringan yang bervariasi dari landai sampai curam. Hal inimenyebabkan banyak daerah di wilayah Gunung Tugel yang berpotensi terjadi bencana tanahlongsor. Pada tahun 2015, peristiwa longsor kembali terjadi di ruas Jalan Gunung Tugel.Kelongsoran yang terjadi sepanjang 70 meter pada separuh badan jalan tersebut menyebabkanarus lalu lintas patikraja-purwokerto menjadi terganggu. Untuk memperbaiki kerusakan jalandan mencegah kelongsoran kembali, diperlukan analisis perkuatan tanah terhadap lerengtersebut. Studi analisis penanggulangan kelongsoran jalan yang terjadi di Gunung Tugel inidilakukan dengan tiga tahapan. Tahapan pertama adalah investigasi lapangan untukmengetahui kondisi lokasi dan dimensi longsor serta mengambil sampel tanah di lapangan.Tahap kedua adalah melakukan pengujian parameter tanah dan analisis data yang diperolehdari lapangan. Tahapan yang terakhir adalah analisis penanggulangan longsor denganmenggunakan data yang diperoleh dari tahapan sebelumnya. Pada penelitan ini, akanditerapkan tiga variasi perkuatan lereng yaitu dinding penahan tanah (DPT), turap dan DPTyang dikombinasikan dengan pondasi tiang. Analisis stabilitas lereng dilakukan dengan metodekeseimbangan batas. Berdasarkan hasil analisis yang dilakukan terhadap ketiga variasiperkuatan, DPT dengan kombinasi tiang pancang lebih direkomendasikan. Penerapan DPTyang dikombinasikan dengan minipile merupakan pilihan yang paling realistis denganpertimbangan tingkat kemudahan pelaksanaan di lapangan. Dari perhitungan yang telahdilakukan, untuk mencapai kondisi stabil diperlukan DPT dengan dimensi tinggi 2 meterdengan lebar bawah 2,5 meter. DPT tersebut ditopang oleh dua tiang tiap penampangmelintang dengan diameter 0,3 meter sepanjang 10 meter dengan jarak antar tiang 1 meter.kata kunci: tanah longsor, perkuatan tanah, metode keseimbangan batas

Tobacco’s Appeal to the Senses and the Early Modern Smoker’s Still Life

2020 ◽  
pp. 123-150
Author(s):  
Julia Saviello
Keyword(s):  
Still Life ◽  
Sense Data ◽  
Complex Image ◽  
Starting Point ◽  
Depth Analysis ◽  
Tobacco Pipes ◽  
Five Senses ◽  
The Senses ◽  
Cut Tobacco ◽  
Selection Of

Smell and taste – of the five senses these are the two most strongly stimulated by smoking tobacco. The article presents an in-depth analysis of the reflection of both these forms of sensory perception in textual and visual sources concerning the early consumption of the herb. In a first step, tobacco’s changing reception, first as medicine and then as stimulant, is traced through the years of its increasing distribution in Europe, starting in the middle of the 16th century. As this overview reveals, at that time the still little known substance gave rise to new forms of sense perception. Following recent studies on smell and gustation, which have stressed the need to take into account the interactions between these senses, the article probes the manifold stimulation of the senses by tobacco with reference to allegorical representations and genre scenes addressing the five senses. The smoking of tobacco was thematized in both of these art forms as a means of visualizing either smell or taste. Yet, these depictions show no indication of any deliberate engagement with the exchange of sense data between mouth and nose. The question posed at the end of this paper is whether this holds true also for early smoker’s still lifes. In the so-called toebakjes or rookertjes, a subgenre of stilllife painting that, like tobacco, was still a novelty at the beginning of the 17th century, various smoking paraphernalia – such as rolled or cut tobacco, pipes and tins – are arrayed with various kinds of foods and drinks. Finally, the article addresses a selection of such smoker’s still lifes, using the toebakje by Pieter Claesz., probably the first of its kind, as a starting point and the work by Georg Flegel as a comparative example. Through their selection of objects, both offer a complex image of how tobacco engages different senses.

Design of Inhibitors for Glyceraldehyde-3-phosphate Dehydrogenase (GAPDH) Enzyme of Leishmania mexicana

2020 ◽  
Vol 16 (6) ◽  
pp. 784-795
Author(s):  
Krisnna M.A. Alves ◽  
Fábio José Bonfim Cardoso ◽  
Kathia M. Honorio ◽  
Fábio A. de Molfetta
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Binding Site ◽  
Point Of View ◽  
New Drugs ◽  
Leishmania Mexicana ◽  
Receptor Complexes ◽  
Starting Point ◽  
Dynamics Simulations ◽  
Selection Of

Background:: Leishmaniosis is a neglected tropical disease and glyceraldehyde 3- phosphate dehydrogenase (GAPDH) is a key enzyme in the design of new drugs to fight this disease. Objective:: The present study aimed to evaluate potential inhibitors of GAPDH enzyme found in Leishmania mexicana (L. mexicana). Methods: A search for novel antileishmanial molecules was carried out based on similarities from the pharmacophoric point of view related to the binding site of the crystallographic enzyme using the ZINCPharmer server. The molecules selected in this screening were subjected to molecular docking and molecular dynamics simulations. Results:: Consensual analysis of the docking energy values was performed, resulting in the selection of ten compounds. These ligand-receptor complexes were visually inspected in order to analyze the main interactions and subjected to toxicophoric evaluation, culminating in the selection of three compounds, which were subsequently submitted to molecular dynamics simulations. The docking results showed that the selected compounds interacted with GAPDH from L. mexicana, especially by hydrogen bonds with Cys166, Arg249, His194, Thr167, and Thr226. From the results obtained from molecular dynamics, it was observed that one of the loop regions, corresponding to the residues 195-222, can be related to the fitting of the substrate at the binding site, assisting in the positioning and the molecular recognition via residues responsible for the catalytic activity. Conclusion:: he use of molecular modeling techniques enabled the identification of promising compounds as inhibitors of the GAPDH enzyme from L. mexicana, and the results obtained here can serve as a starting point to design new and more effective compounds than those currently available.

Application of Gabion Slope Protection of Nanyang River Channel Regulation in Tianzhen County

2011 ◽  
Vol 374-377 ◽  
pp. 1938-1941 ◽  
Author(s):  
Lian Qing Zhao ◽  
Liang Gao ◽  
Hua Jin
Keyword(s):  
Retaining Wall ◽  
Vertical Wall ◽  
River Channel ◽  
Wire Mesh ◽  
Comprehensive Management ◽  
Channel Regulation ◽  
Geological Conditions ◽  
Management Project ◽  
Slope Wall ◽  
Tianzhen County

Nanyang River channel regulation is one of the major projects for river comprehensive management project in Tianzhen reach of the Nanyang River. According to the geological conditions of ecological restoration, Gabion retaining wall is designed to protect the bed or banks of a stream against erosion. Gabion is made of double twisted hexagonal wire mesh, the thickness of gabion basket and mattress is 50 cm and 30 cm respectively. The slope protection work consists of two parts, the lower part is vertical wall and the upper part is slope wall. The results show that this work can solve the problem of uneven settlement and river scouring, sustain restoration of biodiversity and achieve the harmonious coexistence of humanity and nature.

Reflections on the theme issue outcomes

2016 ◽  
Vol 8 (4) ◽  
pp. 504-510
Author(s):  
Gunjan M. Sanjeev ◽  
Richard Teare
Keyword(s):  
Customer Service ◽  
Hospitality Industry ◽  
Theme Issue ◽  
Policy Makers ◽  
Content Type ◽  
Starting Point ◽  
Cost Competitiveness ◽  
Hotel Sector ◽  
Practical Implications ◽  
Selection Of

Purpose The paper aims to profile the theme issue of Worldwide Hospitality and Tourism Themes titled “How is the need for innovation being addressed by the Indian hospitality industry?” with reference to the experiences of the theme editor, contributors from the industry and academia and the theme issue outcomes. Design/methodology/approach The paper uses structured questions to enable the theme editor to reflect on the rationale for their theme issue question, the starting-point, the selection of the writing team and material and the editorial process. Findings It highlights recent innovations that have taken place in the Indian hospitality industry especially in the areas of customer service, cost competitiveness, culinary management, revenue management and technology. Practical implications As hotel sector investment in India intensifies, this theme issue will be of interest to hoteliers, policy makers, analysts and others interested in the role that innovation can play in helping to facilitate differentiation between competing hotel products and services. Originality/value There is limited literature available on industry innovations in the Indian context. All the papers in this theme issue were written after several cycles of interaction between academics and practitioners and so they incorporate real–time, relevant and contemporary data.

Slope Stability Analysis of Elastic Limit Equilibrium Method

2013 ◽  
Vol 275-277 ◽  
pp. 1423-1426
Author(s):  
Lin Kuang ◽  
Ai Zhong Lv ◽  
Yu Zhou
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Slope Stability Analysis ◽  
Sliding Surface ◽  
Tangential Stresses ◽  
Equilibrium Method

Based on finite element analysis software ANSYS, slope stability analysis is carried out by Elastic limiting equilibrium method proposed in this paper. A series of sliding surface of the slope can be assumed firstly, and then stress field along the sliding surface is analyzed as the slope is in elastic state. The normal and tangential stresses along each sliding surface can be obtained, respectively. Then the safety factor for each slip surface can be calculated, the slip surface which the safety factor is smallest is the most dangerous sliding surface. This method is different from the previous limit equilibrium method. For the previous limit equilibrium method, the normal and tangential stresses along the sliding surface are calculated based on many assumptions. While, the limit equilibrium method proposed in this paper has fewer assumptions and clear physical meaning.

Convergence aspect of limit equilibrium methods for slopes

1990 ◽  
Vol 27 (1) ◽  
pp. 145-151 ◽  
Author(s):  
R. N. Chowdhury ◽  
S. Zhang
Keyword(s):  
Factor Of Safety ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Solution Process ◽  
Iterative Solution ◽  
Friction Angle ◽  
Equilibrium Analysis ◽  
Negative Slope ◽  
Slip Surfaces ◽  
Geological Discontinuity

This note is concerned with the multiplicity of solutions for the factor of safety that may be obtained on the basis of the method of slices. Discontinuities in the function for the factor of safety are discussed and the reasons for false convergence in any iterative solution process are explored, with particular reference to the well-known Bishop simplified method (circular slip surfaces) and Janbu simplified or generalized method (slip surfaces of arbitrary shape). The note emphasizes that both the solution method and the method of searching for the critical slip surface must be considered in assessing the potential for numerical difficulties and false convergence. Direct search methods for optimization (e.g., the simplex reflection method) appear to be superior to the grid search or repeated trial methods in this respect. To avoid false convergence, the initially assumed value of factor of safety F0 should be greater than β1(=−tan α1 tan [Formula: see text]) where α1 and [Formula: see text] are respectively the base inclination and internal friction angle of the first slice near the toe of a slope, the slice with the largest negative reverse inclination. A value of F0 = 1 + β1, is recommended on the basis of experience. If there is no slice with a negative slope for any of the slip surfaces generated in the automatic, search process, then any positive value of F0 will lead to true convergence for F. It is necessary to emphasize that no slip surface needs to be rejected for computational reasons except for Sarma's methods and similarly no artificial changes need to be made to the value of [Formula: see text] except for Sarma's methods. Key words: slope stability, convergence, limit equilibrium, analysis, optimization, slip surfaces, geological discontinuity, simplex reflection technique.

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