scholarly journals Experimental Study on the Evolution Mechanism of Landslide with Retaining Wall Locked Segment

Geofluids ◽  
2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Han-Dong Liu ◽  
Jia-Xing Chen ◽  
Zhi-Fei Guo ◽  
Dong-Dong Li ◽  
Ya-Feng Zhang
Keyword(s):  
Shear Fracture ◽  
Retaining Wall ◽  
Stress Test ◽  
Pressure Sensors ◽  
Inertial Force ◽  
Slope Instability ◽  
Evolution Mechanism ◽  
Seismic Force ◽  
Mechanism Of Landslide ◽  
External Loads

The failure of locked segment-type slopes is often affected by rainfall, earthquake, and other external loads. Rainfall scours the slope and weakens the mechanical properties of rock-soil mass. At the same time, rainfall infiltrates into cracks of slope rock mass. Under the action of in situ stress, hydraulic fracturing leads to the development and expansion of rock cracks, which increases the risk of slope instability. Under seismic force, the slope will be subjected to large horizontal inertial force, resulting in slope instability. In this paper, a self-developed loading device was used to simulate the external loads such as rainfall and earthquake, and the model tests are carried out to study the evolution mechanism of landslide with retaining wall locked segment. Three-dimensional laser scanner, microearth pressure sensors, and high-definition camera are applied for the high-precision monitoring of slope shape, deformation, and stress. Test results show that the retaining wall locked segment has an important control effect on landslide stability. The characteristics of deformation evolution and stress response of landslide with retaining wall locked segment are analyzed and studied by changing the slope shape, earth pressure, and the displacement cloud map. The evolutionary process of landslide with retaining wall locked segment is summarized. Experimental results reveal that as the landslide with retaining wall locked segment is at failure, the upper part of the landslide thrusts and slides and the retaining wall produces a locking effect; the middle part extrudes and uplifts, which is accompanied with shallow sliding; and compression-shear fracture of the locked segment leads to the landslide failure.

Calculating Method of Active Earth Pressure behind Rigid Retaining Wall Based on Pseudo-Dynamic Theory

2011 ◽  
Vol 368-373 ◽  
pp. 2932-2938
Author(s):  
Kui Hua Wang ◽  
Deng Hui Wu ◽  
Shao Jun Ma ◽  
Wen Bing Wu
Keyword(s):  
Numerical Analysis ◽  
Dynamic Theory ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Active Earth Pressure ◽  
Active Force ◽  
Calculating Method ◽  
Seismic Active Earth Pressure ◽  
Action Point ◽  
Seismic Force

By means of pseudo-dynamic theory, a new calculating method is presented to calculate the pseudo-dynamic seismic active earth pressure behind rigid retaining wall. Considering time and phase difference within the backfills, the horizontal slices is used to analyze the distribution of seismic active force behind retaining wall in more realistic manner. Under the assumption that the soil backfills are rigid body, the equations derived in this paper can be degenerated to Mononobe-Okabe equations. Through numerical analysis, it is shown that the values of seismic active force obtained from present study are smaller than those obtained from Mononobe-Okabe theory and the distribution of seismic force along the depth of the wall is nonlinear. It is also found that the action point of the total seismic active earth pressure is higher than one third of the wall height, which is corresponding to previous experimental results.

scholarly journals Study on Evolution Mechanism of Structure-Type Rockburst: Insights from Discrete Element Modeling

2021 ◽  
Vol 13 (14) ◽  
pp. 8036
Author(s):  
Chenxi Zhang ◽  
Diyuan Li ◽  
Shunchuan Wu ◽  
Long Chen ◽  
Jun Peng
Keyword(s):  
Shear Fracture ◽  
Pressure Coefficient ◽  
Structural Type ◽  
Structure Type ◽  
Particle Flow Code ◽  
Tensile Fracture ◽  
Discrete Element Modeling ◽  
Structural Plane ◽  
Evolution Mechanism ◽  
Radiated Energy

Taking the “11.28” rockburst occurred in the Jinping II Hydropower Station as the engineering background, the evolution mechanism of structure-type rockburst was studied in detail based on the particle flow code. The results indicate that the failure mechanism of structure-type rockburst includes a tensile fracture induced by tangential compressive stress and a shear fracture caused by shear stress due to overburdened loadings and shear slip on the structural plane. In addition, it is found that the differences between structure-type rockburst and strainburst mainly include (a) the distribution of the local concentrated stress zone after excavation, (b) the evolution mechanism, and (c) the failure locations. Finally, the influence of four factors on the structure-type rockburst are explored. The results show that (1) when the friction coefficient is greater than 0.5, the effect of structural plane is weakened, and the rock near excavation tends to be intact, the structural-type rockburst intensity decreases; (2) the dissipated and radiated energy in structural-type rockburst reduces with rockmass heterogeneity m; (3) the lateral pressure coefficient has a significant effect on the intensity of deep rock failure, specifically in the form of the rapid growth in dissipative energy; (4) and the structural-type rockburst is more pronounced at a structural plane length near 90 mm.

scholarly journals Design of a Tri-Axial Force Measurement Transducer for Plantar Force Measurements

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Weizi Li ◽  
Roberto Dugnani
Keyword(s):  
Dynamic Range ◽  
Force Measurement ◽  
Pressure Sensors ◽  
Rehabilitation Medicine ◽  
Measurement Transducer ◽  
Force Measurements ◽  
Normal Loading ◽  
Shear Loads ◽  
Plantar Force ◽  
External Loads

Transducers for spatial plantar force measurements have numerous applications in biomechanics, rehabilitation medicine, and gait analysis. In this work, the design of a novel, tri-axial transducer for plantar force measurements was presented. The proposed design could resolve both the normal and the shear forces applied at the foot's sole. The novelty of the design consisted in using a rotating bump to translate the external loads into axial compressive forces which could be measured effectively by conventional pressure sensors. For the prototype presented, multilayer polydimethylsiloxane (PDMS) thin-film capacitive stacks were manufactured and used as sensing units, although in principle the design could be extended to various types of sensors. A quasi-static analytic solution to describe the behavior of the transducer was also derived and used to optimize the design. To characterize the performance of the transducer, a 3 cm diameter, 1 cm tall prototype was manufactured and tested under various combination of shear and normal loading scenarios. The tests confirmed the ability of the transducer to generate strong capacitive signals and measure both the magnitude and direction of the normal and shear loads in the dynamic range of interest.

scholarly journals Factor Affecting the Magnitude and the Direction of the Pressure Exerted on the Gravity Retaining Wall

2020 ◽  
Vol 9 (5) ◽  
pp. 1340-1343
Keyword(s):  
Water Table ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Soil Pressure ◽  
Gravity Retaining Wall ◽  
The Earth ◽  
Backfill Soil ◽  
Dry Soil ◽  
The Stability ◽  
External Loads

Gravity retaining wall are structures used to retain the soil by its weight .the stability of such type of walls depend on the magnitude and direction of the horizontal forces exerted by soil . it found that there is many factors affect the value and the acting point of acting. Based on this, a study was conducted to investigate the effect of water table, external vertical loads, sloping of the backfill and the type of the backfill soil. It show that, the value of the horizontal soil pressure increase from147KN/m' on dry soil to about 307 KN/m' as the soil become saturated.also,effect of external loads are studied , and show its increase the total horizontal forces of the soil pressure. Sloping the backfill soil behind the retaining wall also great effect on the earth pressure. The type of the backfill soil behind the retaining wall also investigated and found its effect of the earth forces.

scholarly journals Stability Analysis of a Slope considering Two Reinforcement Processes

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Wei Chen ◽  
Dongbai Li ◽  
Ting Ma ◽  
Helin Fu ◽  
Yanpeng Du
Keyword(s):  
Factor Of Safety ◽  
Failure Time ◽  
Slip Surface ◽  
Distinct Element ◽  
Retaining Wall ◽  
Mining Area ◽  
Steel Tube ◽  
Primary Reinforcement ◽  
Slope Instability ◽  
Engineering Practice

The strength reduction method embedded in a distinct element code was used to analyse the stability of a slope in a coal mining area that had been reinforced twice, primarily with pile and retaining wall, followed by porous steel-tube bored grouting. For the primary reinforcement, the factor of safety was calculated, slip surface and failure mechanism were determined, and the damage phenomenon of primary reinforcement was analysed in detail. Failure time of slope without further strengthening was predicted by applying a new quantitative method based on monitoring displacement data. The slope instability at the primary reinforced stage was verified by these analyses. For the second reinforcement, the effect was evaluated by combining the new factor of safety and the final monitoring data, which validates the slope stability. Especially, variations of displacement and factor of safety due to water influence are analysed. Through this procedure, a systemic method for the slope safety evaluation and assurance is presented for engineering practice reference.

scholarly journals Model Tests and FE-Modelling of Dynamic Soil-Structure Interaction

2012 ◽  
Vol 19 (5) ◽  
pp. 1061-1069
Author(s):  
N. Kodama ◽  
K. Komiya
Keyword(s):  
Soil Structure ◽  
Inertial Force ◽  
Earth Pressure ◽  
Elastic Model ◽  
Clear Understanding ◽  
Interface Model ◽  
Force Transmission ◽  
Fe Modelling ◽  
Seismic Force ◽  
Study Laboratory

The forces applied to a structure from the soil ground during an earthquake and the dynamic response of a structure are problems that are not well understood. In recent years, seismic design technology aided by numerical simulation is under active development. Successful improvement of the accuracy and reliability of numerically simulated results relies on a clear understanding of the seismic force transmission mechanism between the soil and a structure associated with mechanical properties of soil.In this study, laboratory shaking tests were conducted using the unique apparatus designed to have a structure move only by its inertial force and the lateral earth pressure that comes from surrounding sandy soils. The earth pressure at the structure surface and the relative displacement between the soil and the structure were measured in the experiments under various conditions. A new Finite Element interface model for sandy soil-structure dynamic interaction is proposed from the experimental results. Estimated seismic responses of a bridge pier calculated by the proposed interface model, conventional linear elastic model and tension cut-off model are compared.

Messung der Stimmfrequenz im Paargespräch – Chancen für Diagnostik und Intervention in der Paartherapie

2020 ◽  
Vol 68 (4) ◽  
pp. 217-227 ◽  
Author(s):  
Lisanne J. Bulling ◽  
Isabella C. Bertschi ◽  
Céline C. Stadelmann ◽  
Tina Niederer ◽  
Guy Bodenmann
Keyword(s):  
Social Stress ◽  
Stress Test ◽  
Trier Social Stress Test

Zusammenfassung. Die vorliegende Arbeit stellt die bisherigen empirischen Befunde zur Sprachgrundfrequenz (f0) in Paargesprächen vor und untersucht, wie sich die f0 nach einer experimentellen Stressinduktion im anschließenden spontanen Gespräch zwischen den Partner_innen verändert, wie die f0 mit der verbalen Stressäußerung zusammenhängt und wie sie zwischen den beiden Partner_innen kovariiert. Von 128 heterosexuellen Paaren nahm jeweils eine Person pro Paar am Trier Social Stress Test (TSST) teil. Die dem TSST vorangehende und anschließende naturalistische Interaktion zwischen den Partner_innen wurde gefilmt und nach Gesprächsthema und Art der Stressäußerung kodiert. Wie vorherige Studien zur f0 im Paargespräch zeigte auch die vorliegende Studie, dass die f0 wichtige Informationen über die Partnerschaft enthält. Während eine Erhöhung der f0 in Gesprächen über einen paarinternen Stressor (d.h. bei Konfliktgesprächen) mit negativen Kommunikationsmustern einherging, zeigte die vorliegende Studie, dass die f0 bei Gesprächen über einen paarexternen Stressor (d.h. beim TSST) mit emotionsorientierten Stressäußerungen einherging, also einer für den Stressbewältigungsprozess förderlichen Art der Kommunikation. Die Oszillatorenmodelle zeigen darüber hinaus, dass eine Kopplung der f0 zwischen den Partner_innen besteht, was darauf hindeutet, dass die nicht gestressten Partner_innen auf die paraverbalen Stressäußerungen der gestressten Partner_innen mit ihren eigenen paraverbalen Stressäußerungen reagieren.

Stressinduzierte Herabsetzung der Aufmerksamkeit bei jungen Erwachsenen mit ADHS-ähnlicher Symptomatik

2010 ◽  
Vol 39 (4) ◽  
pp. 213-216 ◽  
Author(s):  
Reinhold G. Laessle ◽  
Edith Hansen-Spinger
Keyword(s):  
Stress Test ◽  
Median Split

Zusammenfassung. Theoretischer Hintergrund: Modelle zur Aufrechterhaltung des ADHS-Syndroms postulieren, dass die allgemeine Aufmerksamkeitsleistung und damit auch die Selbstaufmerksamkeit durch Stress vermindert werden kann. Fragestellung: In der Studie wurde geprüft, ob sich dieser Effekt bereits bei Personen aus der gesunden Bevölkerung zeigt, die einen hohen Ausprägungsgrad an ADHS-ähnlicher Symptomatik aufweisen. Methode: 84 Männer mit einem mittleren Alter von 23 Jahren wurden getestet. Die Stressinduktion erfolgte durch mentale Arithmetik aus dem Trier Sozial Stress-Test. Die Aufmerksamkeitsleistung wurde mit dem Frankfurter Aufmerksamkeitsinventar gemessen. Die Gruppierung der Probanden erfolgte durch Median-Split aufgrund der Selbstbeurteilungsskala aus den Homburger ADHS-Skalen für Erwachsene in solche mit hoher bzw. niedriger ADHS-Tendenz. Ergebnisse: Bezüglich der Aufmerksamkeitsleistung zeigte sich der erwartete Interaktionseffekt (Gruppierung × Bedingung) mit schlechterer Leistung nach Stress nur für Personen mit hoher ADHS-Tendenz (p < .002). Schlussfolgerung: Die Ergebnisse deuten auf den Nutzen der Einbeziehung spezifischer stressbezogener Bausteine in Behandlungsprogramme für ADHS-Patienten hin.

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