scholarly journals Estimating soil-water characteristic curve based on soil type and best-fitting regressions derived from a simplified method using Aburra Valley dataset

2021 ◽  
Vol 337 ◽  
pp. 02002
Author(s):  
Johnatan Ramos-Rivera ◽  
Daniel Parra-Holguín ◽  
Yamile Valencia-González ◽  
Oscar Echeverri-Ramírez
Keyword(s):  
Machine Learning ◽  
Soil Water ◽  
Soil Mechanics ◽  
Characteristic Curve ◽  
Computer Code ◽  
Data Set ◽  
Soil Water Characteristic Curve ◽  
Fine Grained ◽  
Simplified Method ◽  
Unsaturated Soil Mechanics

In unsaturated soil mechanics, many attempts have been made to estimate the SWCC based on soil texture and grain-size distribution. This paper proposes a simplified method to estimate the soil-water characteristic curve (SWCC) for both coarse and fine-grained soils using SWCC data and machine learning computer code in the Aburra Valley. Fredlund and Xing parameters has been used to estimate the SWCC correlations. Soil samples collected from field survey were subjected to laboratory testing, SWCCs were estimated using filter paper method. Each SWCC data set from Aburra Valley was fitted with Fredlund and Xing curve using multiple regression analysis, correlations were derived for those four parameters based on predictors derived from machine learning. The proposed method gives a good estimation and low residual errors of the SWCC.

A simplified method to estimate the soil-water characteristic curve

2010 ◽  
Vol 47 (12) ◽  
pp. 1382-1400 ◽  
Author(s):  
Kheng-Boon Chin ◽  
Eng-Choon Leong ◽  
Harianto Rahardjo
Keyword(s):  
Sensitivity Analysis ◽  
Soil Water ◽  
Characteristic Curve ◽  
Estimation Methods ◽  
Index Properties ◽  
Soil Water Characteristic Curve ◽  
Fine Grained ◽  
Simplified Method ◽  
Basic Index ◽  
The One

This paper proposes a simplified method to estimate the soil-water characteristic curve (SWCC) for both coarse- and fine-grained soils using one-point SWCC measurement and basic index properties. Parameters of the Fredlund and Xing SWCC equation were correlated with the basic properties of 60 soils: 30 soils each of coarse- and fine-grained types. Sensitivity analysis revealed that the location of the one-point measurement at matric suctions of 10 and 500 kPa gave the most reliable SWCC using the proposed method for coarse- and fine-grained soils, respectively. The validity of the proposed method was evaluated using a total of 62 soils collated from published literature with 31 soils each of the coarse- and fine-grained types. The proposed method gives a good estimation of the SWCC and uses fewer parameters when compared with existing one-point SWCC estimation methods.

Influences of Deviatoric Stress on the Soil-Water Characteristic Curve

2011 ◽  
Vol 243-249 ◽  
pp. 2456-2459
Author(s):  
Xiang Wei Fang ◽  
Shu Ping Jiang ◽  
Chun Ni Shen ◽  
Yun Xie ◽  
Gang Li
Keyword(s):  
Soil Water ◽  
Unsaturated Soil ◽  
Soil Mechanics ◽  
Characteristic Curve ◽  
Deviatoric Stress ◽  
Mean Stress ◽  
Research Subjects ◽  
Shear Tests ◽  
Soil Water Characteristic Curve ◽  
Unsaturated Soil Mechanics

The soil-water characteristic curve (SWCC) is one of the major research subjects in unsaturated soil mechanics. To study the influence of deviatoric stress on the SWCC of an unsaturated soil, a series of triaxial drained shear tests by controlling constant net mean stress and suction were conducted. It was found that the SWCC was dependent on deviatoric stress. A unified SWCC equation was proposed including not only water content and suction, but also net mean stress and deviatoric stress.

scholarly journals State of practice for use of the soil-water characteristic curve (SWCC) in geotechnical engineering

2019 ◽  
Vol 56 (8) ◽  
pp. 1059-1069 ◽  
Author(s):  
Delwyn G. Fredlund
Keyword(s):  
Soil Water ◽  
Unsaturated Soil ◽  
Soil Mechanics ◽  
Geotechnical Engineering ◽  
Characteristic Curve ◽  
Laboratory Measurement ◽  
Engineering Practice ◽  
Soil Water Characteristic Curve ◽  
Unsaturated Soil Mechanics ◽  
State Of Practice

Routine geotechnical engineering practice has witnessed a significant increase in the usage of unsaturated soil mechanics principles. Laboratory measurement of the soil-water characteristic curve (SWCC) for a soil has been labelled as a primary reason for the improved understanding of unsaturated soil behaviour. Laboratory measurement of the “shrinkage curve” has yielded further insight into the estimation of unsaturated soil property functions (USPFs). The USPFs provide the necessary information for the simultaneous numerical modeling of the saturated and unsaturated portions of the soil profile. This paper presents a state-of-practice summary of the engineering protocols that have emerged amidst the numerous research studies reported over the past couple of decades. It also introduces issues related to hysteresis associated with the SWCC and suggests a pathway forward.

The 1999 R.M. Hardy Lecture: The implementation of unsaturated soil mechanics into geotechnical engineering

2000 ◽  
Vol 37 (5) ◽  
pp. 963-986 ◽  
Author(s):  
Delwyn G Fredlund
Keyword(s):  
Soil Water ◽  
Unsaturated Soil ◽  
Unsaturated Soils ◽  
Soil Property ◽  
Soil Mechanics ◽  
Geotechnical Engineering ◽  
Characteristic Curve ◽  
Engineering Practice ◽  
Soil Water Characteristic Curve ◽  
Unsaturated Soil Mechanics

The implementation of unsaturated soil mechanics into geotechnical engineering practice requires that there be a paradigm shift from classical soil mechanics methodology. The primary drawback to implementation has been the excessive costs required to experimentally measure unsaturated soil properties. The use of the soil-water characteristic curve has been shown to be the key to the implementation of unsaturated soil mechanics. Numerous techniques have been proposed and studied for the assessment of the soil-water characteristic curves. These techniques range from direct laboratory measurement to indirect estimation from grain-size curves and knowledge-based database systems. The soil-water characteristic curve can then be used for the estimation of unsaturated soil property functions. Theoretically based techniques have been proposed for the estimation of soil property functions such as (i) coefficient of permeability, (ii) water storage modulus, and (iii) shear strength. Gradually these estimations are producing acceptable procedures for geotechnical engineering practices for unsaturated soils. The moisture flux ground surface boundary condition is likewise becoming a part of the solution of most problems involving unsaturated soils. The implementation process for unsaturated soils will still require years of collaboration between researchers and practicing geotechnical engineers.Key words: unsaturated soil mechanics, soil suction, unsaturated soil property functions, negative pore-water pressure, matric suction, soil-water characteristic curve.

Model for predicting resilient modulus of unsaturated subgrade soil using soil-water characteristic curve

2015 ◽  
Vol 52 (10) ◽  
pp. 1605-1619 ◽  
Author(s):  
Zhong Han ◽  
Sai K. Vanapalli
Keyword(s):  
Moisture Content ◽  
Soil Water ◽  
Resilient Modulus ◽  
Characteristic Curve ◽  
Optimum Moisture Content ◽  
Model Parameters ◽  
Soil Water Characteristic Curve ◽  
Subgrade Soils ◽  
Fine Grained ◽  
Proposed Model

Soil suction (ψ) is one of the key factors that influence the resilient modulus (MR) of pavement subgrade soils. There are several models available in the literature for predicting the MR–ψ correlations. However, the various model parameters required in the existing models are generally determined by performing regression analysis on extensive experimental data of the MR–ψ relationships, which are cumbersome, expensive, and time-consuming to obtain. In this paper, a model is proposed to predict the variation of the MR with respect to the ψ for compacted fine-grained subgrade soils. The information of (i) the MR values at optimum moisture content condition (MROPT) and saturation condition (MRSAT), which are typically determined for use in pavement design practice; (ii) the ψ values at optimum moisture content condition (ψOPT); and (iii) the soil-water characteristic curve (SWCC) is required for using this model. The proposed model is validated by providing comparisons between the measured and predicted MR–ψ relationships for 11 different compacted fine-grained subgrade soils that were tested following various protocols (a total of 16 sets of data, including 210 testing results). The proposed model was found to be suitable for predicting the variation of the MR with respect to the ψ for all the subgrade soils using a single-valued model parameter ξ, which was found to be equal to 2.0. The proposed model is promising for use in practice, as it only requires conventional soil properties and alleviates the need for experimental determination of the MR–ψ relationships.

Measurement of soil-water characteristic curves for fine-grained soils using a small-scale centrifuge

2002 ◽  
Vol 39 (5) ◽  
pp. 1209-1217 ◽  
Author(s):  
R M Khanzode ◽  
S K Vanapalli ◽  
D G Fredlund
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Characteristic Curve ◽  
Small Scale ◽  
Characteristic Curves ◽  
Pressure Plate ◽  
Soil Water Characteristic Curve ◽  
Fine Grained ◽  
Soil Water Characteristic Curves ◽  
Plate Apparatus

Considerably long periods of time are required to measure soil-water characteristic curves using conventional equipment such as pressure plate apparatus or a Tempe cell. A commercially available, small-scale medical centrifuge with a swinging type rotor assembly was used to measure the soil-water characteristic curves on statically compacted, fine-grained soil specimens. A specimen holder was specially designed to obtain multiple sets of water content versus suction data for measuring the soil-water characteristic curve at a single speed of rotation of the centrifuge. The soil-water characteristic curves were measured for three different types of fine-grained soils. The three soils used in the study were processed silt (liquid limit, wL = 24%; plasticity index, Ip = 0; and clay = 7%), Indian Head till (wL = 35.5%, Ip = 17%, and clay = 30%), and Regina clay (wL = 75.5%, Ip = 21%, and clay = 70%). The soil-water characteristic curves for the above soils were measured in 0.5, 1, and 2 days, respectively, using the centrifuge technique for suction ranges from 0 to 600 kPa. Time periods of 2, 4–6, and 16 weeks were required for measuring the soil-water characteristic curves for the same soils using a conventional pressure plate apparatus. There is reasonably good agreement between the experimental results obtained by the centrifuge and the pressure plate methods. The results of this study are encouraging as soil-water characteristic curves can be measured in a reduced time period when using a small-scale centrifuge.Key words: unsaturated soils, soil-water characteristic curve, centrifuge technique, soil suction, matric suction, water content.

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