A Reconciliation of the Effects of Non-Plastic Fines on the Liquefaction Resistance of Sands Reported in the Literature

2003 ◽  
Vol 19 (3) ◽  
pp. 635-651 ◽  
Author(s):  
Carmine P. Polito ◽  
James R. Martin

The literature presents several seemingly contradictory reports concerning the effects of non-plastic (i.e., silty) fines content on the liquefaction resistance of sands. These seemingly contradictory trends were reconciled in light of the results of a recent study by the authors that linked cyclic resistance and relative density. It was shown that the trend of decreasing cyclic resistance with increasing silt content reported in the literature could be explained by considering the soil's relative density. The same argument was made for the trend of decreasing and then increasing cyclic resistance with increasing silt content. The concept that cyclic resistance is controlled by the sand skeleton void ratio of the soil was also reconciled with the results of the authors’ previous study. The trend of increasing cyclic resistance (without a corresponding initial decrease) with increasing silt content that has been reported in the literature does not appear to occur in non-plastic silts.

2019 ◽  
Vol 281 ◽  
pp. 02001 ◽  
Author(s):  
Layal Jradi ◽  
Bassel Seif El Dine ◽  
Jean-Claude Dupla ◽  
Jean Canou

This paper presents an experimental study that investigates the influence of the non-plastic fines on the initiation of instability of sands under cyclic loading. The materials used for this study and the experimental device are first presented, then the results of typical liquefaction tests for both loose and medium dense specimens are presented with emphasis on the exhibited behaviour. The results of a series of cyclic undrained tests that were done with the aid of a triaxial apparatus for different percentages of fines are also presented and analysed. The results reveal that the increase in the non-plastic fines content lead to an increase in the liquefaction resistance of sands.


2020 ◽  
Vol 57 (3) ◽  
pp. 462-465 ◽  
Author(s):  
Carmine P. Polito ◽  
Erin L.D. Sibley

The threshold fines content of a sand with nonplastic fines represents the silt content where the soil transitions from being a sand matrix, with silt particles entirely contained in the voids between the sands, to being a silt matrix that contains isolated sand grains. A laboratory testing program was performed on a series of mixtures of sand and silt, with silt contents ranging from 0% to 45%, to determine if the friction angle, cyclic resistance, and normalized dissipated energy per unit volume required to initiate liquefaction changed based upon the silt content of the soil relative to the threshold fines content. These data were evaluated with respect to whether the silt content of the specimens was below the lower-bound threshold fines content or above the upper-bound threshold fines content. It was determined that soils above the upper-bound threshold fines content had lower friction angles, lower cyclic resistances, and required less normalized dissipated energy per unit volume to initiate liquefaction than soils below the lower-bound threshold fines content. It was also shown that under the larger strains experienced during monotonic testing, the friction angle did not reach a constant value until it was well above the upper-bound limiting silt content.


2002 ◽  
Vol 39 (1) ◽  
pp. 254-265 ◽  
Author(s):  
Lien-Kwei Chien ◽  
Yan-Nam Oh ◽  
Chih-Hsin Chang

In this study, the reclaimed soils in the Yunlin area of west Taiwan are adopted as test samples. The specimens were prepared by moist tamping at different relative densities and fines contents. Triaxial liquefaction tests were performed to evaluate the liquefaction strength and liquefaction-induced settlement. The test results show that the liquefaction strength of reclaimed soil increases as the relative density increases. In addition, under constant relative density, the liquefaction strength decreases as the fines content increases. Based on the test results and one-dimensional consolidation theory, the volumetric strain and settlement can be evaluated by dry density and fines content of the reclaimed soil. The results show that the settlement ratio decreases as the relative density increases. The figures and results can be references for the evaluation of liquefaction strength and liquefaction-induced settlement. The results are useful for liquefaction strength and settlement analysis for planning, design, and related research on land reclamation engineering.Key words: reclaimed soil, liquefaction resistance, fines content, settlement.


Liquefaction is a phenomenon mainly occurred in saturated fine grained soils under major earthquakes causes tremendous loss to infrastructure. From the literature it has been observed that liquefaction not only occurs in fine sands but also occurs in sands containing some amount of fines particles, which are of less than 75µ in size. Unfortunately there is no clear conclusions given as how effect the fines content on liquefaction resistance of sandy soils. In order to solve above mentioned problem this study was undertaken through stress-controlled cyclic triaxial tests to know the effect of fines content on liquefaction resistance of sandy soils. In this study the program of experimentation was done on base sand and sand mixed with four different combinations of fines like 10%, 20%, 30%, and 40% of fines with base sand by weight.. The main parameters changed in this work were percentage fines and shear stress ratio (CSR ), where the observed parameter was amount of pore water pressure and cycle of loading.. The result showed that, rate of pore water pressure generation during cyclic loading was largely affected by limiting silt content and density index. The trend observed as amount of pore water pressure is increased more than base sand with adding of fines content up to 20%, later the trend observed as reverse. And also noticed that more CSR value increases the pore water pressure generation and decreases the cyclic resistance


2017 ◽  
Vol 54 (10) ◽  
pp. 1460-1471 ◽  
Author(s):  
Katherine A. Kwa ◽  
David W. Airey

This study uses a critical state soil mechanics perspective to understand the mechanics behind the liquefaction of metallic ores during transport by ship. These metallic ores are transported at relatively low densities and have variable gradings containing a wide range of particle sizes and fines contents. The effect of the fines content on the location of the critical state line (CSL) and the cyclic liquefaction behaviour of well-graded materials was investigated by performing saturated, standard drained and undrained monotonic and compression-only cyclic triaxial tests. Samples were prepared at four different gradings containing particle sizes from 9.5 mm to 2 μm with fines (<75 μm) contents of 18%, 28%, 40%, and 60%. In the e versus log[Formula: see text] plane, where e is void ratio and [Formula: see text] is mean effective stress, the CSLs shifted upwards approximately parallel to one another as the fines content was increased. Transitional soil behaviour was observed in samples containing 28%, 40%, and 60% fines. A sample’s cyclic resistance to liquefaction depended on a combination of its density and state parameter, which were both related to the fines content. Samples with the same densities were more resistant to cyclic failure if they contained higher fines contents. The state parameter provided a useful prediction for general behavioural trends of all fines contents studied.


Geosciences ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 330
Author(s):  
Zhixiong Chen ◽  
Hongrui Li ◽  
Anthony Teck Chee Goh ◽  
Chongzhi Wu ◽  
Wengang Zhang

Soil liquefaction is one of the most complicated phenomena to assess in geotechnical earthquake engineering. The conventional procedures developed to determine the liquefaction potential of sandy soil deposits can be categorized into three main groups: Stress-based, strain-based, and energy-based procedures. The main advantage of the energy-based approach over the remaining two methods is the fact that it considers the effects of strain and stress concurrently unlike the stress or strain-based methods. Several liquefaction evaluation procedures and approaches have been developed relating the capacity energy to the initial soil parameters, such as the relative density, initial effective confining pressure, fine contents, and soil textural properties. In this study, based on the capacity energy database by Baziar et al. (2011), analyses have been carried out on a total of 405 previously published tests using soft computing approaches, including Ridge, Lasso & LassoCV, Random Forest, eXtreme Gradient Boost (XGBoost), and Multivariate Adaptive Regression Splines (MARS) approaches, to assess the capacity energy required to trigger liquefaction in sand and silty sands. The results clearly prove the capability of the proposed models and the capacity energy concept to assess liquefaction resistance of soils. It is also proposed that these approaches should be used as cross-validation against each other. The result shows that the capacity energy is most sensitive to the relative density.


2019 ◽  
Vol 92 ◽  
pp. 08009
Author(s):  
Vienti Hadsari ◽  
Adrian R. Russell

An important issue surrounding the identification of liquefaction susceptibility using laboratory testing is how well the soil sample being tested represents the soil in the field. Undisturbed samples are difficult and costly to obtain, while reconstituted soil samples must have a structure and fabric that represents in situ conditions as closely as possible. Recent laboratory tests on sand samples revealed that liquefaction resistance is strongly affected by the sample preparation technique, as different techniques result in different fabrics and structures. The same may be true for silty sand samples, although they have not been given the same research attention. Thus, this paper presents cyclic triaxial test results on non-plastic silty sand samples (a decomposed granite) and determines the number of cycles required to cause liquefaction, considering different failure criterion as well as different confining pressures, cyclic strength ratios and sample preparation techniques. The techniques include dry and slurry deposition. The experimental results show that the preparation technique does not have a significant influence on cyclic resistance.


2001 ◽  
Vol 38 (3) ◽  
pp. 580-591 ◽  
Author(s):  
Y P Vaid ◽  
J D Stedman ◽  
S Sivathayalan

Liquefaction resistance of a sand under cyclic loading is assessed and the effects of the levels of confining pressure and static shear on resistance to liquefaction are investigated. Site-specific values of the resistance under specified levels of confining and static shear stresses are measured in the laboratory. The measured values are compared with those which would be predicted by the application of empirical multiplying factors Kσ and Kα to the reference resistance at 100 kPa effective confining stress with no static shear. It is shown that Kσ and Kα are not independent, as assumed in current practice. The combined factor Kσ × Kα resulting from the empirical method is shown to underestimate the cyclic resistance ratio regardless of the initial density and confining and static shear levels. The degree of conservatism is most dramatic at looser density states.Key words: sand, liquefaction, static, cyclic, static shear, confining stress.


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