scholarly journals Soil parameters’ numerical back analysis for comparison of driven pile’s capacity assessment methods

2020 ◽  
Vol 869 ◽  
pp. 052068
Author(s):  
Piotr Prokopowicz
Keyword(s):  
Back Analysis ◽  
Assessment Methods ◽  
Capacity Assessment ◽  
Soil Parameters

Finite Element Modeling of a Mechanically Stabilized Earth Trial Wall

2021 ◽  
pp. 036119812110164
Author(s):  
Andrew Lees ◽  
Michael Dobie
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Retaining Wall ◽  
Back Analysis ◽  
Soil Parameters ◽  
Failure Behavior ◽  
Valuable Insight ◽  
Deformation And Failure ◽  
First Case ◽  
Soil Shear Strength

Polymer geogrid reinforced soil retaining walls have become commonplace, with routine design generally carried out by limiting equilibrium methods. Finite element analysis (FEA) is becoming more widely used to assess the likely deformation behavior of these structures, although in many cases such analyses over-predict deformation compared with monitored structures. Back-analysis of unit tests and instrumented walls improves the techniques and models used in FEA to represent the soil fill, reinforcement and composite behavior caused by the stabilization effect of the geogrid apertures on the soil particles. This composite behavior is most representatively modeled as enhanced soil shear strength. The back-analysis of two test cases provides valuable insight into the benefits of this approach. In the first case, a unit cell was set up such that one side could yield thereby reaching the active earth pressure state. Using FEA a test without geogrid was modeled to help establish appropriate soil parameters. These parameters were then used to back-analyze a test with geogrid present. Simply using the tensile properties of the geogrid over-predicted the yield pressure but using an enhanced soil shear strength gave a satisfactory comparison with the measured result. In the second case a trial retaining wall was back-analyzed to investigate both deformation and failure, the failure induced by cutting the geogrid after construction using heated wires. The closest fit to the actual deformation and failure behavior was provided by using enhanced fill shear strength.

Evolutional trends of retail risk assessment

10.12737/4105 ◽  
2014 ◽  
Vol 8 (3) ◽  
pp. 132-142
Author(s):  
Людмила Черникова ◽  
Lyudmila Chernikova ◽  
Николай Новичков ◽  
Nikolay Novichkov ◽  
Гузель Фаизова ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Information Technologies ◽  
Historical Perspective ◽  
Retail Banking ◽  
Assessment Methods ◽  
Capacity Assessment ◽  
Evolutionary Trends ◽  
Private Entity ◽  
Banking Development

The article deals with the evolutionary trends of retail risk assessment. The authors present an analysis of the historical perspective on retail banking development and assessment methods. The methods of private entity borrowing capacity assessment are evolving on an ongoing basis due to changes in legislation, the development of information technologies and growing active-bank-operations-related risks. The analysis as conducted by the authors has revealed an evolution of the methods ensuring the enhancement and maintenance of the quality of retail assets. The authors claim that scoring is to be considers with due regard to the significance of the technological component, and dwell on their vision of this definition.

Back-Analysis of Indoor Test Parameters for Rock-Fill of Shui Bu Ya CFRD

2011 ◽  
Vol 243-249 ◽  
pp. 4581-4586
Author(s):  
Lei Ming He ◽  
Li Hui Du ◽  
Jian Yang
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Back Analysis ◽  
Soil Parameters ◽  
Model Parameters ◽  
Analysis Method ◽  
Filling Process ◽  
Rock Fill ◽  
Test Parameters ◽  
Displacement Back Analysis

In the numerical calculation of geotechnical project, it’s difficult to confirm the parameters because of the complexity and the uncertainty of them as the time is changing. However, the back-analysis provides us an effective way. Based on the result of the triaxial test on rock-fill of Shui Bu Ya CFRD, the thesis adopts the direct back-analysis method which combines the BP Neural Network and Genetic Algorithm to calculate the Tsinghua non-linear K-G model parameters of the rock-fill. The back-analysis parameters are used to simulate the filling process of Shui Bu Ya CFRD and predict the displacement of the dam. The thesis provides a technical reference for displacement back-analysis of soil parameters for CFRD.

scholarly journals Comparison of two colorimetric antioxidant capacity assessment methods in bovine semen fractions

2016 ◽  
Vol 05 (Special issue 1) ◽  
pp. 47-49
Author(s):  
Eva Tvrdá ◽  
Monika Schneidgenová ◽  
Tomáš Jambor ◽  
Dušan Paál ◽  
Csaba Szabó ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Assessment Methods ◽  
Capacity Assessment ◽  
Bovine Semen

Pressuremeter Investigation for Mass Rapid Transit in Bangkok, Thailand

2005 ◽  
Vol 1928 (1) ◽  
pp. 206-217 ◽  
Author(s):  
Richard E. Prust ◽  
John Davies ◽  
Shuang Hu
Keyword(s):  
Back Analysis ◽  
Site Investigation ◽  
Design Parameters ◽  
Soil Parameters ◽  
Rapid Transit ◽  
Underground Structures ◽  
Ground Conditions ◽  
Strength And Stiffness ◽  
Slurry Walls ◽  
Mass Rapid Transit

The 20-km (12.5-mi) mass rapid transit underground railway system in central Bangkok, Thailand, recently opened for passengers. During construction, the project was divided into two separate civil design–build contracts: the northern section, comprising approximately 10 km (6.2 mi) of twin bored tunnels, and nine stations constructed within slurry walls by adopting top-down techniques. A crucial part of the design of the underground structures was the selection of appropriate design parameters for the slurry walls. The contractor was responsible for ground-related issues and carried out a detailed site investigation to confirm the ground conditions and define soil parameters for the design of the underground structures. The site investigation comprised 40 conventional wash-bored borings and six self-boring pressuremeter tests. This paper describes the site investigation that was carried out for the project and the ground conditions that were encountered, with particular focus on the use of the self-boring pressuremeter to estimate the soil strength, stiffness, and in situ pressure for use in design of the slurry walls. The paper discusses the various methods used to interpret the data and compares the parameters derived from the pressuremeter to those derived from other methods and from back-analysis of the behavior of the wall during construction. It is concluded that in the conditions in Bangkok, the pressuremeter testing provided higher strength and stiffness values than determined from other methods and that these parameters were subsequently borne out by the behavior of the underground structures.

Finite element modelling of pullout testing on a soil nail in a pullout box under different overburden and grouting pressures

2011 ◽  
Vol 48 (4) ◽  
pp. 557-567 ◽  
Author(s):  
Wan-Huan Zhou ◽  
Jian-Hua Yin ◽  
Cheng-Yu Hong
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Back Analysis ◽  
Soil Mass ◽  
Friction Model ◽  
Soil Parameters ◽  
Fe Model ◽  
Fe Modelling ◽  
Soil Nail ◽  
Pullout Behaviour

In this paper, a three-dimensional (3D) finite element (FE) model is developed to simulate the pullout behaviour of a soil nail in a soil-nail pullout box under different overburden and grouting pressures. The FE model simulates all the procedures of a pullout test on a grouted soil nail in a compacted and saturated completely decomposed granite (CDG) soil. The stress–strain behaviour of the CDG soil is described by a modified Drucker–Prager/Cap model, while that of the soil–nail interface is represented by the Coulomb friction model. Triaxial experiment data are used to calibrate the soil parameters in the soil constitutive model. The interface parameters are determined from back-analysis with the laboratory soil-nail pullout data. The soil stress variations surrounding the soil nail during drilling, grouting, saturation, and pullout are all well simulated by the FE modelling and compared with available test data. The comparisons between the modelling and experimental data have shown that the established FE can well simulate the pullout behaviour of a soil nail in a soil mass. Based on this, the verified FE model has the potential to simulate the performance of a soil nail in a field soil slope.

scholarly journals Systematic slope stability assessment through deformation field monitoring

2019 ◽  
Vol 92 ◽  
pp. 18009
Author(s):  
Yukun Wei ◽  
Anders B. Lundberg ◽  
Fredrik Resare
Keyword(s):  
Slope Stability ◽  
Measurement Data ◽  
Back Analysis ◽  
Field Measurements ◽  
Field Monitoring ◽  
Monitoring Data ◽  
Soil Parameters ◽  
Stability Assessment ◽  
Stability Of Slopes ◽  
The Stability

Field monitoring is frequently carried out during excavations and other geotechnical activities and provides additional information during the execution of a construction project. The interpretation of field monitoring data is often obscured by measurement noise and disturbance, and a systematic approach to assess both the quality and implications of the field monitoring data is very helpful in geotechnical practice. The possibility to infer practical conclusions from the field monitoring data depends on the type of field measurements, especially in monitoring of the stability of slopes. Pore pressure measurements can serve as a direct measurement of utilized soil strength for a slope, while deformation measurements are significantly more ambiguous and complicates the interpretation. The assessment of slope stability through field monitoring of deformations requires inverse or back analysis of the soil properties, followed by a forward analysis of the resulting slope stability. Such an inverse or back analysis is frequently influenced by non-uniqueness of the material properties and the stability of the measurement data. Systematic approaches to inverse or back analysis have been demonstrated in the scientific literature, but the practical use of these methods is not entirely straight-forward. The current paper presents a case study of systematic slope stability assessment through field measurements of deformations with a review of the field monitoring programme, numerical simulations of deformations, and a simplified approach to back analysis of the soil parameters. The excavation of a slope in an urban environment including layers of organic clay covered with highly heterogeneous gravel fill is used as an example of geotechnical back analysis. The aim is to elucidate some of the challenges in geotechnical back analysis while providing some practical solutions for practice.

scholarly journals Multi-temporal LiDAR-DTMs as a tool for modelling a complex landslide: a case study in the Rotolon catchment (eastern Italian Alps)

2015 ◽  
Vol 15 (4) ◽  
pp. 715-722 ◽  
Author(s):  
G. Bossi ◽  
M. Cavalli ◽  
S. Crema ◽  
S. Frigerio ◽  
B. Quan Luna ◽  
...  
Keyword(s):  
Debris Flow ◽  
Back Analysis ◽  
Civil Defense ◽  
Airborne Lidar ◽  
Soil Parameters ◽  
Analysis Model ◽  
Italian Alps ◽  
Emergency Plans ◽  
Landslide Event ◽  
Before And After

Abstract. The geomorphological change detection through the comparison of repeated topographic surveys is a recent approach that benefits greatly from the latest developments in topographical data acquisition techniques. Among them, airborne LiDAR makes the monitoring of geomorphological changes a more reliable and accurate approach for natural hazard and risk management. In this study, two LiDAR digital terrain models (DTMs) (2 m resolution) were acquired just before and after a complex 340 000 m3 landslide event (4 November 2010) that generated a debris flow in the channel of the Rotolon catchment (eastern Italian Alps). The analysis of these data was used to set up the initial condition for the application of a dynamic model. The comparison between the pre- and post-event DTMs allowed us to identify erosion and depositional areas and the volume of the landslide. The knowledge of the phenomenon dynamics was the base of a sound back analysis of the event with the 3-D numerical model DAN3D. This particular code was selected for its capability to modify the rheology and the parameters of the moving mass during run-out, as actually observed along the path of the 2010 debris flow. Nowadays some portions of Mt. Rotolon flank are still moving and show signs of detachment. The same soil parameters used in the back-analysis model could be used to simulate the run-out for possible future landslides, allowing us to generate reliable risk scenarios useful for awareness of civil defense and strategy of emergency plans.

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