Influence of strain-rate on hydromechanical behavior of highly compacted GMZ01 bentonite

Qin, Pengju; Ye, Weimin; Chen, Yong-Gui; Bao, Changchun; Cui, Yu-Jun

doi:10.1016/j.enggeo.2015.05.028

Cited by 17 publications

(24 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many experiments were conducted to understand the loading rate influence on unsaturated soil specimens. For example, the strain rate can affect the yield stress value and the compression behavior of the specimen (Qin et al 2015), and at high suction levels, the loading rate will change the soil stiffness (Rojas & Mancuso 2009). Wu et al (2020) showed that increasing the strain rate will lead to decrease the degree of saturation and the volumetric strain of the unsaturated specimen at the critical state.…”

Section: Methodsmentioning

confidence: 99%

Compression Response of Sedimented Unsaturated Soils

Behbehani

McCartney

2022

J. Geotech. Geoenviron. Eng.

View full text Add to dashboard Cite

This paper presents an experimental study on the hydro-mechanical behavior of unsaturated sedimented soil to understand the impacts of suction on the apparent yield stress and gain insight into the differences in behavior from compacted soils. A large-strain oedometer was developed for use in a triaxial cell that permits initial sedimentation of soils from a slurry under backpressure, suction control using the axis translation technique, and mechanical loading to characterize the compression curve. A flow pump was used to control the pore water pressure at the base of the soil specimen and to track water flow during suction application and mechanical loading. After initial consolidation of saturated soil specimens from a slurry, the specimens were unloaded, different suction values were applied, then the axial stress was increased to 11 MPa at a constant strain rate. An increase in apparent yield stress with suction was observed, and the compression curves for higher suctions diverged without reaching pressurized saturation in the applied stress range. When compared with compression curves for the same soil compacted dry of optimum presented in previous studies, the sedimented soil had a greater yield stress at saturated conditions but a similar increase in yield stress with suction. Sedimented soils also experienced smaller changes in void ratio with applied net stress and a higher air entry suction value compared to compacted soils, reflecting a more compact soil structure. Suction was found to have a greater impact on yield stress than suction stress for both sedimented and compacted soils.

show abstract

Section: Methodsmentioning

confidence: 99%

Compression Response of Sedimented Unsaturated Soils

Behbehani

McCartney

2022

J. Geotech. Geoenviron. Eng.

View full text Add to dashboard Cite

show abstract

“…on the time-dependent behavior of unsaturated geomaterials. 6,9 Based on the experimental results for saturated soils, numerous empirical relations and rheological models were proposed to predict the time-dependent behavior of soils, including creep, stress relaxation and rate effects. 2,10,11 Some more advanced relationships between stress, strain and time (or strain rate) were constructed within the elasto-viscoplastic (EVP) frame, for instance, the over-stress theory 12 and the non-stationary flow surface (NSFS) theory.…”

Section: Introductionmentioning

confidence: 99%

“…Besides, a gradual hardening law is incorporated into this model, allowing the description of smooth stress-strain curves and creep phenomenon at a very low stress. Finally, the proposed model is validated based on the experimental results from CRS tests, 9 triaxial shear tests, 6 and triaxial creep tests. [23][24][25]…”

Section: Introductionmentioning

confidence: 99%

A viscoplastic constitutive model for unsaturated soils based on nonstationary flow surface theory

Wang,

Cui

2023

Num Anal Meth Geomechanics

View full text Add to dashboard Cite

A viscoplastic constitutive model is developed to describe the viscoplastic behavior of unsaturated soils. The proposed model accounts for the stain‐rate and suction effects on yield by adopting an unsaturated isotach concept. The nonstationary flow surface theory (NSFS) is applied for modeling the viscoplastic behavior, with the yield surface which can evolve with the viscoplastic strain, viscoplastic strain rate and suction. Meanwhile, the progressively hardening concept is adopted for reproducing the viscoplastic behavior of soil at an over‐consolidated state. For the validation, a series of loading conditions are considered based on the data from the literature. Results show that the proposed model is able to reproduce the main viscoplastic behaviors of unsaturated highly compacted Gaomiaozi (GMZ) bentonite, Glenroy silt and Qianjiangping landslide (QL) soil, including CRS compression tests, rate‐dependent triaxial shear tests, and triaxial creep tests.

show abstract

“…Moreover, CRS tests can obtain continuous data—rather than discrete data based on load increment size—which can improve the accuracy of consolidation mechanical parameters [ 6 ]. CRS tests are used to investigate compressibility of unsaturated soils in the recent decades [ 7 , 8 , 9 , 10 , 11 , 12 ]. In [ 9 ], a static compaction apparatus was developed to study the post-compaction suction change of a kaolin clay by applying a loading rate of five kilopascals per minute under a constant water content condition.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, a rate of two micrometers per minute was adopted for studying the compression properties of unsaturated silt soil [ 14 ]. Qin et al [ 12 ] studied influence of strain-rate on hydromechanical behavior of highly compacted bentonite by single-stage and stepwise CRS tests at ambient temperature and verified the applicability of the isotache concept on the compacted bentonite.…”

Section: Introductionmentioning

confidence: 99%

An Electrical Resistivity Method of Characterizing Hydromechanical and Structural Properties of Compacted Loess During Constant Rate of Strain Compression

Qin

Liu

Song

et al. 2020

Sensors

View full text Add to dashboard Cite

Hydromechanical and structural properties of compacted loess have a significant impact on the stability and reliability of subbase and subgrade, which needs to be quickly determined in the field and laboratory. Hence, an electrical resistivity method was used to characterize the hydromechanical and structural properties of compacted loess during constant rate of strain compression. In the present work, compacted loess samples with a dry density of 1.7 g/cm3, a diameter of 64 mm, a height of 10 mm and different water content ranging from 5–25% were prepared. The constant rate of strain (CRS) tests were conducted by a developed oedometer cell equipped with a pair of horizontal circular electrodes (diameter of 20 mm) and vertical rectangular electrodes (width of 3.5 mm) to determine the electrical resistivity of compacted loess. The results showed that as average water content increases, plastic compression indices increase from 0.220 to 0.350 and the elastic compression indices increase from 0.0152 to 0.030, but they decrease to 0.167 and 0.010 and yield stress decreases from 381.28 kPa to 72.35 kPa. Moreover, as vertical strain increases, the variation trend of average formation factor and average shape factor for the lower water content decreases but increases for the maximum water content, and the anisotropy index first decrease and then tend to increase slightly, which indicates that the structural properties of unsaturated and saturated samples during compression exhibits different trend and the anisotropy of samples tend to be stable as vertical strain increases. As the water content increases, the average formation factor and average shape factor decrease, but the anisotropy index first decreases then increases, suggesting that water content has a significant impact on these electrical indices. More important, The coefficients of average formation factor decrease from 33.830 to −1.698 and the coefficients of average shape factor decrease from 8.339 to −0.398 as water content increases, whereas there is less variation for the coefficient of anisotropic index with a value of 2.190. An equation correlating average formation factor and water content and vertical strain is regressed to characterize the hydromechanical properties of compacted loess by measuring its impedance, which can be used to evaluate the stability of compacted loessic ground and subgrade.

show abstract

Influence of strain-rate on hydromechanical behavior of highly compacted GMZ01 bentonite

Cited by 17 publications

References 47 publications

Compression Response of Sedimented Unsaturated Soils

Compression Response of Sedimented Unsaturated Soils

A viscoplastic constitutive model for unsaturated soils based on nonstationary flow surface theory

An Electrical Resistivity Method of Characterizing Hydromechanical and Structural Properties of Compacted Loess During Constant Rate of Strain Compression

Contact Info

Product

Resources

About