scholarly journals Back Analysis of Self-Compacting Concrete Rheological Parameters Based on H-B Model

2015 ◽  
Author(s):  
Shuai Zeng ◽  
Jianjun Shi ◽  
Wenqiang Guo
Keyword(s):  
Back Analysis ◽  
Rheological Parameters ◽  
Self Compacting Concrete

Back analysis of a rock landslide to infer rheological parameters

2012 ◽  
Vol 131-132 ◽  
pp. 45-56 ◽  
Author(s):  
F. Bozzano ◽  
S. Martino ◽  
A. Montagna ◽  
A. Prestininzi
Keyword(s):  
Back Analysis ◽  
Rheological Parameters ◽  
Rock Landslide

Back Analysis Methods in Geotechnical Engineering

2014 ◽  
Vol 1020 ◽  
pp. 423-428 ◽  
Author(s):  
Eva Hrubesova ◽  
Marek Mohyla
Keyword(s):  
Rock Mass ◽  
Geotechnical Engineering ◽  
Back Analysis ◽  
Rheological Parameters ◽  
Analysis Method ◽  
Direct Optimization ◽  
Initial Stress State ◽  
Analytical Functions ◽  
Is Evaluation

The paper deals with the back analysis method in geotechnical engineering, that goal is evaluation the more objective and reliable parameters of the rock mass on the basis of in-situ measurements. Stress, deformational, strength and rheological parameters of the rock mass are usually determined by some inaccuracies and errors arising from the complexity and variability of the rock mass. This higher or lower degree of imprecision is reflected in the reliability of the mathematical modelling results. The paper presents the utilization of direct optimization back analysis method, based on the theory of analytical functions of complex variable and Kolosov-Muschelischvili relations, to the evaluation of initial stress state inside the rock massif.

Workability tests and rheological parameters in self-compacting concrete

2008 ◽  
Vol 42 (7) ◽  
pp. 947-960 ◽  
Author(s):  
R. Zerbino ◽  
B. Barragán ◽  
T. Garcia ◽  
L. Agulló ◽  
R. Gettu
Keyword(s):  
Rheological Parameters ◽  
Self Compacting Concrete

scholarly journals Debris flow run-out simulation and analysis using a dynamic model

2018 ◽  
Vol 18 (2) ◽  
pp. 555-570 ◽  
Author(s):  
Raquel Melo ◽  
Theo van Asch ◽  
José L. Zêzere
Keyword(s):  
Debris Flow ◽  
Dynamic Model ◽  
Debris Flows ◽  
Back Analysis ◽  
Rheological Parameters ◽  
Economic Damage ◽  
Case Scenario ◽  
Worst Case ◽  
Basin Scale ◽  
Central Portugal

Abstract. Only two months after a huge forest fire occurred in the upper part of a valley located in central Portugal, several debris flows were triggered by intense rainfall. The event caused infrastructural and economic damage, although no lives were lost. The present research aims to simulate the run-out of two debris flows that occurred during the event as well as to calculate via back-analysis the rheological parameters and the excess rain involved. Thus, a dynamic model was used, which integrates surface runoff, concentrated erosion along the channels, propagation and deposition of flow material. Afterwards, the model was validated using 32 debris flows triggered during the same event that were not considered for calibration. The rheological and entrainment parameters obtained for the most accurate simulation were then used to perform three scenarios of debris flow run-out on the basin scale. The results were confronted with the existing buildings exposed in the study area and the worst-case scenario showed a potential inundation that may affect 345 buildings. In addition, six streams where debris flow occurred in the past and caused material damage and loss of lives were identified.

scholarly journals On the use of the calibration-based approach for debris-flow forward-analyses

2010 ◽  
Vol 10 (5) ◽  
pp. 1009-1019 ◽  
Author(s):  
M. Pirulli
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Single Phase ◽  
Back Analysis ◽  
Numerical Approach ◽  
Rheological Parameters ◽  
Trial And Error ◽  
Back Calculation ◽  
Selection Of ◽  
Volume Size

Abstract. In the present paper the problem of modeling the propagation of potential debris flows is tackled resorting to a numerical approach. In particular, numerical analyses are carried out with the RASH3D code, based on a single-phase depth-averaged continuum mechanics approach. Since each numerical analysis requires the selection of a rheology and the setting of the rheological input parameters, a calibration-based approach, where the rheological parameters are constrained by systematic adjustment during trial-and-error back-analysis of full-scale events, has been assumed. The back-analysis of a 1000 m3 debris flow, located at Tate's Cairn, Hong Kong, and the forward-analysis of a 10 000 m3 potential debris flow, located in the same basin have been used to investigate the transferability of back-calculated rheological parameters from one case to another. Three different rheologies have been tested: Frictional, Voellmy and Quadratic. From obtained results it emerges that 1) the back-calculation of a past event with different rheologies can help in selecting the rheology that better reproduces the runout of the analysed event and, on the basis of that selection, can give some indication about the dynamics of the investigated flow, 2) the use of back-calculated parameters for forward purposes requires that past and potential events have similar characteristics, some of which are a function of the assumed rheology. Among tested rheologies, it is observed that the Quadratic rheology is more influenced by volume size than Frictional and Voellmy rheologies and consequently its application requires that events are also similar in volume.

scholarly journals Numerical Modelling of Self-Compacting Concrete Flow

2019 ◽  
Vol 8 (6) ◽  
pp. 5192-5199
Keyword(s):  
Initial Step ◽  
Material Model ◽  
Rheological Parameters ◽  
Homogeneous Material ◽  
Nonspherical Particles ◽  
Self Compacting Concrete ◽  
Test Volume ◽  
Molecule Model ◽  
Concrete Flow ◽  
The Ideal

With the appearance of Self-Compacting Concrete (SCC) that streams uninhibitedly, under the sole impact of gravity, the desire for issue free and unsurprising castings even in complex cases, spurged the recreation of solid stream as a way to demonstrate and anticipate solid functionality. To accomplish total and dependable structure loading up with smooth surfaces of the solid, the fortified formwork geometry must be perfect with the rheology of the new SCC. Anticipating stream conduct in the formwork and connecting the required rheological parameters to stream tests performed on the site will guarantee an improvement of the throwing procedure. In this theory, numerical reproduction of solid stream is explored, utilizing both discrete just as constant approaches. The discrete molecule model here fills in as a way to mimic subtleties and marvels concerning totals demonstrated as individual items. The here gave cases are reenacted round particles. Be that as it may, it is conceivable to utilize nonspherical particles too. Total surface harshness, size and viewpoint proportion might be modeles by molecule erosion, size and bunching a few circles into framing the ideal molecule shape. The consistent methodology has been utilized to mimic huge volumes of cement. The solid is displayed as a homogeneous material, specific impacts of totals, for example, blocking or isolation are not represented. Great correspondence was accomplished with a Bingham material model used to reenact solid research center tests (for example droop stream, L-box) and structure filling. Stream of cement in an especially clogged segment of a twofold tee chunk just as two lifts of a multi-layered full scale divider throwing were reenactedsucessfully. A huge scale quantitative investigation is performed rather easily with the constant methodology. Littler scale subtleties and marvels are better caught subjectively with the discrete molecule approach. As PC speed and limit always develops, recreation detail and test volume will be permitted to increment. A future converging of the homogeneous liquid model with the molecule way to deal with structure particles in the liquid will highlight the progression of concrete as the physical suspension that it speaks to. One single ellipsoidal molecule falling in a Newtonian liquid was considered as an initial step.

scholarly journals Assessing potential debris flow runout: a comparison of two simulation models

2008 ◽  
Vol 8 (4) ◽  
pp. 961-971 ◽  
Author(s):  
M. Pirulli ◽  
G. Sorbino
Keyword(s):  
Debris Flow ◽  
Back Analysis ◽  
Simulation Models ◽  
Numerical Code ◽  
Rheological Parameters ◽  
Rheological Parameter ◽  
Safe Side ◽  
Study Sites ◽  
Comparison Of The Results ◽  
Parameter Values

Abstract. In the present paper some of the problems related to the application of the continuum mechanics modelling to debris flow runout simulation are discussed. Particularly, a procedure is proposed to face the uncertainties in the choice of a numerical code and in the setting of rheological parameter values that arise when the prediction of a debris flow propagation is required. In this frame, the two codes RASH3D and FLO2D are used to numerically analyse the propagation of potential debris flows affecting two study sites in Southern Italy. For these two study sites, a lack in information prevents that the rheological parameters can be obtained from the back analysis of similar well documented debris flow events in the area. As a prediction of the possible runout area is however required by decision makers, an alternative approach based on the analysis of the alluvial fans existing at the toe of the two studied basins is proposed to calibrate rheological parameters on the safe side. From the comparison of the results obtained with RASH3D (where a Voellmy and a Quadratic rheologies are implemented) and FLO2D (where a Quadratic rheology is implemented) it emerges that, for the two examined cases, numerical analyses carried out with RASH3D assuming a Voellmy rheology can be considered on the safe side respect to those carried out with a Quadratic rheology.

scholarly journals Debris flow run-out simulation and analysis using a dynamic model

2017 ◽  
Author(s):  
Raquel Melo ◽  
Theo van Asch ◽  
José L. Zêzere
Keyword(s):  
Debris Flow ◽  
Dynamic Model ◽  
Debris Flows ◽  
Back Analysis ◽  
Quantitative Information ◽  
Rheological Parameters ◽  
Case Scenario ◽  
Worst Case ◽  
Basin Scale ◽  
Central Portugal

Abstract. Only two months after a huge wildfire occurred in the upper part of a valley located in Central Portugal, several debris flows were triggered by intense rainfall. The event caused infrastructural and economical damage, although no life was lost. The present research aims to simulate the run-out of two debris flows occurred during the event as well as to calculate by back-analysis the rheological parameters and the excess rain involved. Thus, a dynamic model was used, which integrates surface runoff, concentrated erosion along the channels, propagation and deposition of flow material. The rheological and entrainment parameters obtained for the most accurate simulation were then used to perform three scenarios of debris flows run-out at the basin scale. Due to the lack of quantitative information to validate these models, the results were compared with historical references of debris flow events in the study area. Six streams were identified, where debris flows occurred in the past and caused material damage and loss of lives. The worst-case scenario carried out at the basin scale shows a potential inundation that may affect 345 buildings at the present day.

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