scholarly journals Application of analog and numerical models to investigate the influence of drainage on workability in spring.

1976 ◽  
Vol 24 (3) ◽  
pp. 155-172
Author(s):  
G.P. Wind
Keyword(s):  
Numerical Models ◽  
Pronounced Effect ◽  
Analog Model ◽  
Moisture Flow ◽  
Top Soil ◽  
Moisture Conditions ◽  
Unsaturated Moisture Flow

Models of non-steady unsaturated moisture flow were used to calculate moisture conditions in a top soil from natural rain and evaporation data for 23 years. The calculations were made with 5 drainage depths and 3 drainage intensities using an analog model. The number of days when the soil was workable and the first workable day showed large variations over the years. Drainage depth had a pronounced effect on workability but drainage intensity had hardly any effect. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Boundary integral solutions to the unsaturated moisture flow equation

1993 ◽  
Vol 29 (5) ◽  
pp. 1425-1434 ◽  
Author(s):  
Reza M. Khanbilvardi ◽  
Shabbir Ahmed ◽  
Ali M. Sadegh
Keyword(s):  
Flow Equation ◽  
Boundary Integral ◽  
Moisture Flow ◽  
Integral Solutions ◽  
Unsaturated Moisture Flow

scholarly journals Dealing with deep uncertainties in landslide modelling for disaster risk reduction under climate change

2016 ◽  
Author(s):  
Susana Almeida ◽  
Elizabeth Holcombe ◽  
Francesca Pianosi ◽  
Thorsten Wagener
Keyword(s):  
Slope Stability ◽  
Slope Failure ◽  
Numerical Models ◽  
Landslide Risk ◽  
Residual Soils ◽  
Soil Thickness ◽  
Economic Changes ◽  
Critical Thresholds ◽  
Top Soil ◽  
Steep Slopes

Abstract. Landslides have large negative economic and societal impacts, including loss of life and damage to infrastructure. Slope stability assessment is a vital tool for landslide risk management, but high levels of uncertainty often challenge its usefulness. Uncertainties are associated with the numerical model used to assess slope stability and its parameters, with the data characterising the geometric, geotechnic and hydrologic properties of the slope, and with hazard triggers (e.g., rainfall). Uncertainties associated with many of these factors are also likely to be exacerbated further by future climatic and socio-economic changes, such as increased urbanisation and resultant land use change. In this study, we illustrate how numerical models can be used to explore the uncertain factors that influence potential future landslide hazard using a bottom-up strategy. Specifically, we link the Combined Hydrology And Stability Model (CHASM) with sensitivity analysis and Classification And Regression Trees (CART) to identify critical thresholds in slope properties and climatic (rainfall) drivers that lead to slope failure. We apply our approach to a slope in the Caribbean, an area that is naturally susceptible to landslides due to a combination of high rainfall rates, steep slopes, and highly weathered residual soils. For this particular slope, we find that uncertainties regarding some slope properties (namely thickness and effective cohesion of top soil) are as important as the uncertainties related to future rainfall conditions. Furthermore, we show that 89 % of the expected behaviour of the studied slope can be characterised based on only two variables – the ratio of top soil thickness to cohesion and the ratio of rainfall intensity to duration.

Modelling moisture conditions behind brick veneer cladding: Verification of common approaches by field measurements

2020 ◽  
Vol 44 (2) ◽  
pp. 95-120 ◽  
Author(s):  
Michiel Vanpachtenbeke ◽  
Jelle Langmans ◽  
Jan Van den Bulcke ◽  
Joris Van Acker ◽  
Staf Roels
Keyword(s):  
Numerical Models ◽  
Field Measurements ◽  
Field Studies ◽  
Ventilation Rate ◽  
Two Dimensional ◽  
Building Enclosure ◽  
Air Change Rate ◽  
Brick Veneer ◽  
Moisture Conditions

Cavity walls consisting of an outer leaf, a cavity and an inner leaf are a widespread building enclosure configuration because of their good performance regarding rain tightness. To increase the drying potential, open head joints are typically provided in the brick outer leaf, creating cavity ventilation. Even though this cavity ventilation has a limited effect on the drying out of the brick veneer, it can significantly reduce the moisture levels inside the cavity. This might be crucial when the brick veneer is combined with, for example, a wooden load-bearing wall. A reliable prediction of the cavity moisture levels is hence essential. However, previous studies showed that the ventilation rate in the cavity is highly fluctuating in both magnitude and direction. That is why most numerical models simplify cavity ventilation by neglecting it, replacing it by an equivalent resistance, assuming a constant air change rate and so on. This article verifies common assumptions in numerical models to incorporate cavity ventilation behind a brick veneer cladding, by confronting the simulations with detailed field studies. The results showed that for walls exposed to driving rain and solar radiation, most simplified one-dimensional simulations do not suffice to predict the moisture content in the cavity in a reliable way. Only with two-dimensional simulations, incorporating the airflow in the cavity, a good agreement with the in situ measurements was obtained. Furthermore, the two-dimensional models showed to be able to capture the moisture gradient along with the height of the wall rather precisely.

scholarly journals 3D Stress Analysis of Multilayered Functionally Graded Plates and Shells under Moisture Conditions

2022 ◽  
Vol 12 (1) ◽  
pp. 512
Author(s):  
Salvatore Brischetto ◽  
Roberto Torre
Keyword(s):  
Steady State ◽  
Diffusion Equation ◽  
Stress Analysis ◽  
Numerical Models ◽  
Functionally Graded ◽  
Analytical Models ◽  
Direct Result ◽  
Equilibrium Equations ◽  
Plates And Shells ◽  
Moisture Conditions

This paper presents the steady-state stress analysis of single-layered and multilayered plates and shells embedding Functionally Graded Material (FGM) layers under moisture conditions. This solution relies on an exact layer-wise approach; the formulation is unique despite the geometry. It studies spherical and cylindrical shells, cylinders, and plates in an orthogonal mixed curvilinear coordinate system (α, β, z). The moisture conditions are defined at the external surfaces and evaluated in the thickness direction under steady-state conditions following three procedures. This solution handles the 3D Fick diffusion equation, the 1D Fick diffusion equation, and the a priori assumed linear profile. The paper discusses their assumptions and the different results they deliver. Once defined, the moisture content acts as an external load; this leads to a system of three non-homogeneous second-order differential equilibrium equations. The 3D problem is reduced to a system of partial differential equations in the thickness coordinate, solved via the exponential matrix method. It returns the displacements and their z-derivatives as a direct result. The paper validates the model by comparing the results with 3D analytical models proposed in the literature and numerical models. Then, new results are presented for one-layered and multilayered FGM plates, cylinders, and cylindrical and spherical shells, considering different moisture contents, thickness ratios, and material laws.

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