scholarly journals Studies on Cyclic and Dynamic Loading on Cohesive Soil in Road Engineering

2016 ◽  
Author(s):  
Wojciech Sas ◽  
Andrzej Głuchowski ◽  
Katarzyna Gabryś ◽  
Emil Soból ◽  
Alojzy Szymański
Keyword(s):  
Dynamic Loading ◽  
Resilient Modulus ◽  
Poisson Ratio ◽  
Cohesive Soil ◽  
Repeated Loading ◽  
Cohesive Soils ◽  
Laboratory Equipment ◽  
Road Design ◽  
Triaxial Apparatus ◽  
Soil Behaviour

Soil investigations concerning cyclic and dynamic loading differ from static analysis. The Problem with the abovementioned loads becomes more important, when cohesive soils are taken into consideration. There are plenty of scientific reports containing the analyses of non-cohesive soil behaviour, yet there is still a lack of similar studies on cohesive soils. Repeated loading and dynamic excitations differ between themselves and parameters which are used to describe those phenomena are not congruent. Road constructors seek new approaches to design methods, which would take into account more types dynamic and cyclic excitations. For a successful utilisation of these occurrences in designing codes, mechanical parameters, such as resilient modulus Mr, shear modulus G and Poisson ratio υ or dumping ratio D, need to be determined. The laboratory tests were conducted on sandy clays, which are a common soil in Poland, using specialized laboratory equipment, such as a resonant column and cyclic triaxial apparatus. The aim of the work presented in this paper was to measureand analyse the abovementioned mechanical characteristics. The paper ends with conclusions regarding the application of cyclic and dynamic loading characteristics in road design.

Correlation between Resilient Modulus and Plastic Deformation for Cohesive Subgrade Soil under Repeated Loading

2008 ◽  
Vol 2053 (1) ◽  
pp. 72-79 ◽  
Author(s):  
Shu-Rong Yang ◽  
Wei-Hsing Huang ◽  
Chi-Chou Liao
Keyword(s):  
Plastic Deformation ◽  
Plastic Strain ◽  
Strain Hardening ◽  
Resilient Modulus ◽  
Cohesive Soil ◽  
Repeated Loading ◽  
Hardening Behavior ◽  
Subgrade Soil ◽  
Stress Levels ◽  
Strain Hardening Behavior

Pavement performance is related to resilient modulus and plastic deformation of pavement materials, which in turn are affected by environmental conditions and traffic loading. A series of triaxial tests was conducted on a residual lateritic soil for 10,000 load repetitions, with some specimens subjected to 100,000 load repetitions, to characterize the behavior of cohesive subgrades under repeated loading, including resilient modulus and plastic deformation. The shakedown concept was used to describe the accumulated plastic deformation and the strain-hardening and softening behavior. Experimental results show that the resilient modulus of cohesive subgrades exhibits strain-hardening behavior under low stress levels. In the meantime, the rate of plastic strain accumulation becomes diminutive. Soil under this condition is in a stable state. Conversely, under high stress levels, cohesive soil tends to soften after a specific number of load applications and accumulates excessive plastic strain and leads to an unstable state. To predict the plastic strain of subgrade soil under repetitive loading, regression models incorporating the strain-hardening behavior for a cohesive soil were used.

Model for Resilient Modulus and Permanent Strain of Subgrade Soils

1998 ◽  
Vol 1619 (1) ◽  
pp. 85-93 ◽  
Author(s):  
A.S. Muhanna ◽  
M.S. Rahman ◽  
P.C. Lambe
Keyword(s):  
Simple Model ◽  
Plastic Strain ◽  
Confidence Intervals ◽  
Empirical Model ◽  
Resilient Modulus ◽  
Cohesive Soil ◽  
Repeated Loading ◽  
Subgrade Soils ◽  
Permanent Strain ◽  
Proposed Model

The resilient modulus and cumulative permanent strain of subgrade soils under anticipated repeated loading are important considerations for the design of a pavement against fatigue and rutting failures. A simple model was developed to evaluate the resilient modulus and accumulated permanent strain of cohesive subgrade soils under repeated loads. The empirical model was derived from the observed behavior of an A-6 cohesive soil. The model was tested against an A-5 soil. The proposed model was found to predict adequately the resilient modulus and the accumulated plastic strain for all A-6 and A-5 specimens with 90 percent confidence intervals of 0.61 and 1.4, and 0.66 and 1.39, respectively.

scholarly journals Studies on resilient modulus value from cyclic loading tests for cohesive soil

2017 ◽  
Vol 49 (2) ◽  
pp. 117-127 ◽  
Author(s):  
Wojciech Sas ◽  
Andrzej Głuchowski ◽  
Maciej Miturski
Keyword(s):  
Cyclic Loading ◽  
Triaxial Test ◽  
Resilient Modulus ◽  
Cohesive Soil ◽  
Cyclic Test ◽  
Repeated Loading ◽  
Silty Clay ◽  
Cbr Test ◽  
Loading Tests ◽  
Cyclic Loading Tests

Abstract In this article the cyclic CBR test as a reference method in determination of resilient modulus (Mr) is confronted with results of cyclic triaxial and unconfined uniaxial cyclic test. The main idea of conducted experiments is establish relationship between cyclic loading tests in testing of natural subsoil and road materials. The article shows results of investigation on cohesive soil, namely sandy silty clay, commonly problematic soil in Poland. The results of repeated loading triaxial test resilient modulus were displayed in order to compare them with cyclic CBR test results by using the Mr–Ө model. Some empirical correlation between factors obtained from triaxial test or uniaxial unconfined cyclic test and cyclic CBR test was introduced here. The behavior of resilient modulus was also examined in this paper.

Resilient modulus of cohesive soils and the effect of freeze–thaw

1995 ◽  
Vol 32 (4) ◽  
pp. 559-568 ◽  
Author(s):  
Woojin Lee ◽  
N.C. Bohra ◽  
A.G. Altschaeffl ◽  
T.D. White
Keyword(s):  
Resilient Modulus ◽  
Empirical Relationship ◽  
Cohesive Soil ◽  
Cohesive Soils ◽  
Unconfined Compression ◽  
Unconfined Compression Test ◽  
Freeze Thaw ◽  
Deviator Stress ◽  
A Value ◽  
Lens Formation

Resilient modulus tests were performed on five cohesive soils sampled from the subgrades of in-service pavements. The stress at 1% strain in the unconfined compression test (Su1.0%) was found to be a good indicator of the resilient modulus (MR), and an empirical relationship between MR and Su1.0% was obtained. The proposed relationship itself is not affected by the changes in subgrade after construction and, therefore, is applicable to as-compacted and in-service subgrade conditions. Closed-system freeze–thaw tests were also performed and the effect of freeze–thaw on the resilient modulus was studied. There is a negligible effect of freeze–thaw, without ice lens formation, for soils having values of Su1.0% less than 8 psi (55 kPa), while the effect of freeze–thaw increases as the value of Su1.0% increases. For example, a soil with a value of Su1.0% greater than 15 psi (103 kPa) would exhibit more than 50% reduction in resilient modulus due to the effect of freeze–thaw. The resilient modulus of frozen cohesive soil is independent of the repeated deviator stress. Key words : resilient modulus, subgrade, pavement, freeze–thaw.

Experimental Study on Critical Shear Stress of Cohesive Soils and Soil Mixtures

2021 ◽  
Vol 64 (2) ◽  
pp. 587-600
Author(s):  
Xiaojing Gao ◽  
Qiusheng Wang ◽  
Chongbang Xu ◽  
Ruilin Su
Keyword(s):  
Experimental Data ◽  
Shear Stress ◽  
Critical Shear Stress ◽  
Cohesive Soil ◽  
Future Research ◽  
Cohesive Soils ◽  
List Type ◽  
Soil Mixture ◽  
Linear Relationships ◽  
Soil Mixtures

HighlightsErosion tests were performed to study the critical shear stress of cohesive soils and soil mixtures.Linear relationships were observed between critical shear stress and cohesion of cohesive soils.Mixture critical shear stress relates to noncohesive particle size and cohesive soil erodibility.A formula for calculating the critical shear stress of soil mixtures is proposed and verified.Abstract. The incipient motion of soil is an important engineering property that impacts reservoir sedimentation, stable channel design, river bed degradation, and dam breach. Due to numerous factors influencing the erodibility parameters, the study of critical shear stress (tc) of cohesive soils and soil mixtures is still far from mature. In this study, erosion experiments were conducted to investigate the influence of soil properties on the tc of remolded cohesive soils and cohesive and noncohesive soil mixtures with mud contents varying from 0% to 100% using an erosion function apparatus (EFA). For cohesive soils, direct linear relationships were observed between tc and cohesion (c). The critical shear stress for soil mixture (tcm) erosion increased monotonically with an increase in mud content (pm). The median diameter of noncohesive soil (Ds), the void ratio (e), and the organic content of cohesive soil also influenced tcm. A formula for calculating tcm considering the effect of pm and the tc of noncohesive soil and pure mud was developed. The proposed formula was validated using experimental data from the present and previous research, and it can reproduce the variation of tcm for reconstituted soil mixtures. To use the proposed formula to predict the tcm for artificial engineering problems, experimental erosion tests should be performed. Future research should further test the proposed formula based on additional experimental data. Keywords: Cohesive and noncohesive soil mixture, Critical shear stress, Erodibility, Mud content, Soil property.

Prediction of Resilient Modulus of Compacted Cohesive Soils in South China

2019 ◽  
Vol 19 (7) ◽  
pp. 04019068 ◽  
Author(s):  
Junhui Zhang ◽  
Junhui Peng ◽  
Jianlong Zheng ◽  
Liangliang Dai ◽  
Yongsheng Yao
Keyword(s):  
South China ◽  
Resilient Modulus ◽  
Cohesive Soils

Laboratory Testing: Assessing BS 5930

1986 ◽  
Vol 2 (1) ◽  
pp. 43-52 ◽  
Author(s):  
D. W. Hight
Keyword(s):  
Effective Stress ◽  
Site Investigation ◽  
Triaxial Tests ◽  
Cohesive Soils ◽  
Deformation Parameters ◽  
Strength And Deformation ◽  
Soil Behaviour ◽  
Measured Strength ◽  
Linear Nature

AbstractEstablished patterns of soil behaviour are used to illustrate: the divergence between parameters from laboratory and in situ tests; the changes in effective stress caused by sampling; and the influence of initial effective stress, p′0 on the measured strength and deformation parameters for cohesive soils.Current practice in onshore site investigation continues to make use of the unconsolidated undrained triaxial test in which p′0 is not controlled. Variations in p′0 after sampling and subsequent handling are shown to contribute to the scatter in undrained compression strength data.A plea is made for BS 5930 to encourage the measurement of effective stress in all undrained triaxial tests; to recognise the non-linear nature of soils; and to urge integration of laboratory and in situ tests.

scholarly journals Estimation of physical and mechanical properties of cohesive soil stabilized by hydratized lime addition

2013 ◽  
Vol 45 (2) ◽  
Author(s):  
Wojciech Sas ◽  
Andrzej Głuchowski ◽  
Jarosław Margielski
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Cohesive Soil ◽  
Hydrated Lime ◽  
Chemical Stabilization ◽  
Cohesive Soils ◽  
Silty Clay ◽  
Cbr Test ◽  
The Impact ◽  
Lime Addition

AbstractEstimation of physical and mechanical properties of cohesive soil stabilized by hydratized lime addition. Process of chemical stabilization of cohesive soils influences its mechanical properties, also in the case of soil cohesion. Road constructions consist of few layers which have various mechanical properties and this creates the need for better understanding the impact of chemical stabilization on soil as a layer of road. For the purposes of this article, tests were carried out in order to establish physical and mechanical properties, especially the penetrating resistance CBR test. The main aim of this paper was to estimate the cohesion of the soil, which was sandy-silty clay stabilized with hydrated lime

scholarly journals RESULTS OF COMPRESSION TESTING ON PSEUDO-COHESIVE SOIL

Vestnik MGSU ◽  
2015 ◽  
pp. 61-72
Author(s):  
Vadim Grigor’evich Ofrikhter ◽  
Yan Vadimovich Ofrikhter
Keyword(s):  
Void Ratio ◽  
Retaining Wall ◽  
Time Moment ◽  
Cohesive Soil ◽  
Cohesive Soils ◽  
Test Results ◽  
Creep Tests ◽  
Compression Process ◽  
Secondary Compression ◽  
Deformation Equation

Natural non-treated sand reinforced with randomly oriented short polypropylene fibers of 12 mm in length was tested to determine creep characteristics. This study is a part of the research aimed at encouraging fibrosand (FRS) application in subsoils, embankments and retaining wall constructions. Fiber content was accounted for 0.93 %. Twin specimens were put to creep tests (1-D compression) using the two curve method. The test results were analyzed and checked with the use of ageing, hardening and hereditary creep theories. On the basis of approximation of the test results the creep deformation equation at constant stress for tested fibrosand was obtained. The assessment of fibrosand secondary compression was carried out by the FORE method. As a result, the value of the void ratio by the end of the secondary compression had been eu=0.7041. For determination of the beginning of the secondary compression the rate equation was superimposed on the empirical curve. The point of the graph divergence is the beginning of the secondary compression process. The secondary compression had begun by the time moment being equal to 9360 min. The void ratio by the beginning of the secondary compression had amounted to 0.70574. Fibrosand is a specific type of improved soil relating to so-called pseudo-cohesive soil. This type of soil is characterized by cohesion like cohesive soils, but, at the same time, by the filtration coefficient of about 1 m per day like non-cohesive soils. Pseudo-cohesive soil testing helps to understand the distinctive features of the stress-strain state of this kind of materials. Municipal solid waste also relates to them.

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