Behavior of a fine-grained soil during the Loma Prieta earthquake

1998 ◽  
Vol 35 (1) ◽  
pp. 146-158 ◽  
Author(s):  
Ross W Boulanger ◽  
Mark W Meyers ◽  
Lelio H Mejia ◽  
Izzat M Idriss

Results of an investigation into the behavior of a fine-grained clayey soil at Moss Landing during the 1989 Loma Prieta earthquake are presented. A deposit of this soil underlies portions of the Moss Landing Marine Laboratory that experienced up to 1.3 m of lateral spreading deformations during this magnitude 7 earthquake. Silty clay from the deposit erupted to the surface in a "soil boil" characteristic of liquefaction, during and immediately after the earthquake. A sample from the silty clay boil had a liquid limit of 38, a plasticity index of 17, and a <5 µm fraction of 24%, and thus would be considered nonliquefiable according to commonly used criteria. Analysis of cyclic triaxial test data suggests that portions of the silty clay deposit likely developed high residual excess pore pressures (ru,r approx 80-90%) and significant shear strains during the earthquake and thus likely contributed to the observed lateral deformations. The field and laboratory data show that commonly used criteria for identifying "liquefiable" clayey soils should be applied with caution and should not be indiscriminately viewed as a substitute for detailed laboratory and in situ testing of low plasticity fine-grained soils.Key words: liquefaction, cyclic loading, silt, clay, earthquake, case history.

1999 ◽  
Vol 36 (3) ◽  
pp. 584 ◽  
Author(s):  
Ross W Boulanger ◽  
Lelio H Mejia ◽  
Mark W Myers ◽  
Izzat M Idriss

2018 ◽  
Vol 162 ◽  
pp. 01017
Author(s):  
Kawther Al-Soudany

This paper evaluates the use of silica fumes as modification of fine-grained soil in order to alter undesirable properties of the native soil and create new useful soils. Silica fume as well as clay material, are used in changing the engineering properties to be compatible and satisfying this is due to their pozzolanic reactivity. The study aims to investigate the uses of these materials in geotechnical engineering and to improve the properties of soils. Four percentages of silica fumes were used in the present study, which is 0, 3, 5 and 7%. Classification, specific gravity, compaction characteristics, swell and swell pressure, CBR and compressive strength tests had been conducted on the prepared and modified soils. Results clarified that the silica fume increasing leads to decrease the plasticity index and liquid limit. Increasing in silica fume causes an increasing in plastic limit and optimum water contents while the maximum dry unit weight values decrease. The compressive shear strength, California Bearing Ratio (CBR), swell and swell pressure is improved by using silica fume so that silica fume can be considered as a successful material in improving the soil properties.


2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Junhui Zhang ◽  
Yongsheng Yao ◽  
Jianlong Zheng ◽  
Xiangqun Huang ◽  
Tian Lan

To determine the degree of compaction of subgrades filled with fine-grained soil, the compaction test and light dynamic penetrometer (LDP) test were carried out for low liquid-limit clay samples with different water contents in laboratory. Then, a prediction equation of the penetration ratio (PR) defined as the depth per drop of the hammer of LDP, degree of compaction (K), and water content (ω) was built. After that, the existing fine-grained soil subgrades on LDP-based field tests were excavated. The on-site PR values, water contents, and degrees of compaction of slopes were obtained. The estimated degrees of compaction using the prediction equation were compared with measured values of the degree of compaction in field. The results show that there is good consistency between them, and an error within 3.5% was obtained. In addition, the water content should be determined firstly while using the prediction equation which is proposed in this study. Therefore, a numerical method of the water content of a subgrade was developed, and the predicted and measured water contents were compared, which shows a relatively high relativity. Then, the degree of compaction of fine-grained soil subgrades can be calculated according to the predicting equation, which involves the penetration ratio (PR) and the numerically calculated water content as input instead of the measured value in the field.


2020 ◽  
Vol 17 (12) ◽  
pp. 1367-1378
Author(s):  
Prinya CHINDAPRASIRT ◽  
Apichit KAMPALA ◽  
Anukun ARNGBUNTA ◽  
Suksun HORPIBULSUK

Soil stratum in Khon Kaen province, located in Northeast of Thailand, is well-known as a wind-deposited fine-grained soil (i.e. silty sand and silty clay). It is normally called “Loess or Khon Kaen Loess”.  This soil in disturbed stage is usually extracted from the borrow pit and subsequently compacted for infrastructure applications. The compaction resulted in silty sand or silty clay aggregation with unpredictable properties. Although required for infrastructure design, studies on Khon Kaen Loess are limited. Thus, this research examines the compaction behavior and predicts soil parameters at various clay contents under a series of compaction energy on Khon Kaen Loess. The results showed that the maximum dry unit weights of samples could be related to the dry unit weight at plastic limit (PL), while the optimum water content (OWC) was correlated linearly with the PL. The samples with higher PL presented the higher OWC. In addition, the maximum dry unit weight and OWC of samples could be estimated using the developed equations validated with the other research results.


Geosciences ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 247
Author(s):  
Amin Soltani ◽  
Brendan C. O’Kelly

Given its apparent limitations, various attempts have been made to develop alternative testing approaches to the standardized rolling-thread plastic limit (PLRT) method (for fine-grained soils), targeting higher degrees of repeatability and reproducibility. Among these, device-rolling techniques, including the method described in ASTM D4318/AASHTO T90 standards, based on original work by Bobrowski and Griekspoor (BG) and which follows the same basic principles as the standard thread-rolling (by hand) test, have been highly underrated by some researchers. To better understand the true potentials and/or limitations of the BG method for soil plasticity determination (i.e., PLBG), this paper presents a critical reappraisal of the PLRT–PLBG relationship using a comprehensive statistical analysis performed on a large and diverse database of 60 PLRT–PLBG test pairs. It is demonstrated that for a given fine-grained soil, the BG and RT methods produce essentially similar PL values. The 95% lower and upper (water content) statistical agreement limits between PLBG and PLRT were, respectively, obtained as −5.03% and +4.51%, and both deemed “statistically insignificant” when compared to the inductively-defined reference limit of ±8% (i.e., the highest possible difference in PLRT based on its repeatability, as reported in the literature). Furthermore, the likelihoods of PLBG underestimating and overestimating PLRT were 50% and 40%, respectively; debunking the notion presented by some researchers that the BG method generally tends to greatly underestimate PLRT. It is also shown that the degree of underestimation/overestimation does not systematically change with changes in basic soil properties; suggesting that the differences between PLBG and PLRT are most likely random in nature. Compared to PLRT, the likelihood of achieving consistent soil classifications employing PLBG (along with the liquid limit) was shown to be 98%, with the identified discrepancies being cases that plot relatively close to the A-Line. As such, PLBG can be used with confidence for soil classification purposes.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Fatih Isik ◽  
R. Kagan Akbulut ◽  
A. Sahin Zaimoglu

AbstractThe use of waste materials in civil engineering applications has gained importance nowadays. Consuming limited natural resources and increasing waste disposal costs have led researchers to evaluate waste materials for different geotechnical applications. In this respect, some waste materials are used as reinforcement in soils to improve their engineering properties. The main objective of this paper was to investigate the usability of waste polypropylene fiber as a reinforcement material in high plasticity fine-grained soils. For this purpose, waste toothbrush bristle (WTB) was used as a polypropylene fiber reinforcement material and added to fine-grained soil at ratios of 0.2%, 0.4%, 0.6% and 0.8% by dry total weight. The effect of WTB on freezing–thawing behavior and unconfined compression strength of unreinforced and reinforced clayey soil was evaluated. The results indicated that addition of WTB to high plasticity clay improved its behavior against freezing–thawing. Also, undrained shear strength increases with respect to increment in WTB ratio.


1973 ◽  
Vol 10 (4) ◽  
pp. 617-631 ◽  
Author(s):  
John F. Nixon

In order to assess the stability and deformation qualities of thawing arctic soils, a theory of thaw–consolidation must be established to predict the dissipation of excess pore fluids. The predictive power of current mathematical models is considerably enhanced by consideration of some common departures from homogeneity. In the first instance a permafrost profile of two different soil types is analyzed numerically, each layer having different thermal and geotechnical properties. The presence of a surficial layer, although minor in extent, may influence for a considerable time the behavior of the underlying layer. Secondly, the excess pore pressures in a fine-grained soil overlying an ice layer are treated theoretically, and the results suggest that foundation conditions over a thawing ice layer may not be as critical as sometimes is supposed.


2020 ◽  
Vol 57 (6) ◽  
pp. 933-938
Author(s):  
Nilo Cesar Consoli ◽  
Eduardo José Bittar Marin ◽  
Rubén Alejandro Quiñónez Samaniego ◽  
Hugo Carlos Scheuermann Filho ◽  
Nuno Miguel Cordeiro Cristelo

Fine-grained soils, due to their high plasticity, possess great shrinkage potential and high compressibility and are responsible for very substantial maintenance costs during the service life of the associated infrastructures. Stabilization of such soils with lime is one of the most effective procedures to mitigate these undesirable characteristics and, at the same time, to enhance their mechanical properties. Current research seeks, through field and laboratory tests, to quantify the influence of calcitic hydrated lime on the strength and deflection characteristics clayey soil from the Paraguayan region of Chaco. The influence of different dry unit weights, lime amounts, and curing periods on the strength and deflection of a Paraguayan clay stabilized with lime was assessed. The present work shows, for the first time ever, that the porosity/lime index is the proper parameter to be used in the field when dealing with the strength of clay–lime bases of pavements. Hence, the results presented herein are a contribution to understanding the conditions in which these soils can be stabilized to be used in infrastructural applications.


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