The Trial Research of Soil-Water Characteristic Curves of Unsaturated Soil and its Engineering Application

2012 ◽  
Vol 170-173 ◽  
pp. 3050-3053
Author(s):  
Cui Ran Liu ◽  
Jin Jun Guo
Keyword(s):  
Soil Water ◽  
Unsaturated Soil ◽  
Permeability Coefficient ◽  
Characteristic Curve ◽  
Engineering Application ◽  
Engineering Properties ◽  
Confining Pressures ◽  
Soil Water Characteristic Curves ◽  
Matrix Suction ◽  
Water Contents

With the improved triaxial equipment, the tests of research of the relationships between matrix suction and water content are performed And based on the test data, the curves between matrix suction and water contents under different confining pressures are drawn and the change rule between them are analyzed. And then the function between them is simulated out. Through the soil-water characteristic curve, the permeability coefficient of unsaturated soil can be calculated and the shear strength of unsaturated soil can be predicted. These results are important to research the engineering properties of unsaturated soil.

The Study of Correction Method for Soil-Water Characteristic Curve of Swelling-Shrinking Soil

2013 ◽  
Vol 712-715 ◽  
pp. 873-876
Author(s):  
Peng Du ◽  
Xiao Ling Liu ◽  
Xiao Ying Li
Keyword(s):  
Soil Water ◽  
Volume Fraction ◽  
Characteristic Curve ◽  
Correction Method ◽  
Matric Suction ◽  
Engineering Properties ◽  
Water Volume ◽  
Volume Deformation ◽  
Water Volume Fraction ◽  
The Relationship

The swelling-shrinking soil embodies the features of expanding when absorbing water and shrinking when drying out; its engineering properties are sensitive to water fluctuation. Mainstream test instruments of SWCC cannot accurately get its relationship between matric suction and water volume fraction. So a correction method based on the results of shrinkage test is carried out. The method is accomplished by using the volume deformation which is obtained in shrinkage test to calculate its real water volume fraction and then combining the results of SWCC test and finally constructing the relationship between matric suction and water volume fraction. Through real application, this method is proved to be feasible and essential.

Nanotechnology in Geotechnical Engineering

2011 ◽  
Vol 261-263 ◽  
pp. 524-528 ◽  
Author(s):  
Marzieh Kadivar ◽  
Kazem Barkhordari ◽  
Mehdi Kadivar
Keyword(s):  
Geotechnical Engineering ◽  
Engineering Properties ◽  
Index Properties ◽  
Recent Advances ◽  
Electron Microscopes ◽  
Geotechnical Studies ◽  
Properties Of Soil

The present paper reviews the application of nanotechnology in geotechnical engineering, in which the concept of nanotechnology as well as the new concept of nanosol is explained. We have also given explanation for nanometer additives used in the introduced soil, different forms of nanoparticles, their specific properties, and effects of these nanoparticles on engineering properties of soil including index properties and strength, and analyzed the reasons through which these effects are caused. Furthermore, influence of recent advances in nanoinstruments and electron microscopes as well as their application in geotechnical studies.

scholarly journals GEOTECHNICAL INFLUENCE OF UNDERLYING SOILS TO PAVEMENT FAILURE IN SOUTHWESTERN PART OF NIGERIA

2018 ◽  
Vol 4 (1) ◽  
pp. 19 ◽  
Author(s):  
Ademila Omowumi
Keyword(s):  
Water Adsorption ◽  
Construction Materials ◽  
High Water ◽  
Engineering Properties ◽  
Swelling Potential ◽  
Failure Characteristics ◽  
The Road ◽  
Subgrade Soils ◽  
Subgrade Soil ◽  
Low Stiffness

Roads in Nigeria are usually constructed without in-depth knowledge of the subsoil that serves as the foundation for the road elements. Road failures are often associated to poor construction materials or inadequate design without cognisance of the underlying soils. Engineering properties of ten bulk soil samples collected from the subgrade of Arigidi/Oke-Agbe highway were investigated to determine their suitability for highway pavement. Results show that all the subgrade soils below the failed locations have higher plasticity indices, which is an indication of their high swelling potential, and they are classified as A-7-6 clayey soils with high-water adsorption capability (16.1 – 22.4%) compared to subgrade soils from the stable locations. Low compacted density (1325 – 1928 Kg/m3), extremely poor CBR values; 8 – 31% (unsoaked) and 3 – 8% (soaked) which indicate percentage reduction in strength of the soils up to 77% on exposure to excessive moisture and the predominance of fines (> 59%) in the soils are responsible for the degree of instability. Furthermore, soft to low stiffness (49 – 131 kN/m2) and poor permeability of the subgrade materials underlying the pavement result to the failure characteristics witnessed. This study shows that the suitability and behaviour of subgrade soil is dependent on its engineering properties.

A New Method for Measuring the Soil-Water Retention Curve of Red Clay

2013 ◽  
Vol 815 ◽  
pp. 796-802
Author(s):  
Pan Chen ◽  
Chang Fu Wei
Keyword(s):  
Soil Water ◽  
Rapid Method ◽  
Water Retention ◽  
New Method ◽  
Engineering Properties ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Red Clay ◽  
Retention Curve

Red clay is normally used in the area of Guangxi for roadbed filling and slope overburden. The engineering properties of red clay are closely related with the hydraulic characteristics. A new rapid method is adopted for measuring the soil-water retention curve of the red clay based on the dynamic multi-step outflow tests. The static soil-water retention curve is obtained through the non-equilibrium changes of soil-water under each step of matric suction. Compared with the traditional measured methods, the new method can save much time for determining the hydraulic characteristic functions, especially for clay soils. Several experiments are done under different suction steps and load time on the same red clay sample for verifying the effectiveness of the new rapid method. The experimental results show that the static soil-water data are largely dependent on the initial several suction steps and load time in the dynamic multi-step outflow tests. If the suitable loading scheme is adopted in the dynamic multi-step outflow method, the time can be saved greatly for obtaining the soil-water characteristic curve and hydraulic conductivity function of red clay. The significance of the rapid method will great for the engineering design and evaluation related with unsaturated red clay.

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.

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