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.

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.

scholarly journals Correlation Between Cone Resistance Values and Cohesion Values in Cohesive Soils (Case Study in Gunung Anyar District)

2021 ◽  
Vol 328 ◽  
pp. 01005
Author(s):  
Fithri Estikhamah ◽  
Dian Purnamawati Solin
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Secondary Data ◽  
Cohesive Soil ◽  
Soil Types ◽  
Primary Data ◽  
Cohesive Soils ◽  
Cone Resistance ◽  
A Value ◽  
Resistance Value

The physical and mechanical properties of the soil can be determined based on laboratory tests by testing soil samples obtained from field drilling. At one point it can be done simultaneously between SPT testing and drilling. Therefore, it can be known simultaneously the value of N-SPT with the physical and mechanical properties of the soil. The purpose of this study was to obtain a relationship between the cone resistance value (qc) obtained in the field and the cohesion value for cohesive soil types. This study uses primary data, and secondary data. The results of the correlation between the cone resistance value (qc) obtained in the field and the cohesion value for cohesive soil types show a strong correlation. This is indicated by the regression value which reaches a value of 0.75, which is 0.7809. The regression equation obtained is y = 0.0138x – 0.0063. The coefficient of the cone resistance value is 0.0138, indicating that every 1 constant increase in the cone resistance value variable will increase the cohesive value in the cohesive soil by 0.0138. The positive regression coefficient indicates that the higher the cone resistance value (qc), the higher the value of cohesion (c) for cohesive soils.

Evaluation of Resilient Modulus for Lime- and Cement-Stabilized Synthetic Cohesive Soils

1997 ◽  
Vol 1589 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Francis Achampong ◽  
Mumtaz Usmen ◽  
Takaaki Kagawa
Keyword(s):  
Resilient Modulus ◽  
Mineralogical Composition ◽  
Cohesive Soils ◽  
High Plasticity ◽  
Regression Equations ◽  
Predictive Regression ◽  
Deviator Stress ◽  
Curing Period ◽  
Student’S T ◽  
Stabilizer Type

The effects of deviator stress, molding moisture content, stabilizer type and content, curing period, and soil type on the resilient modulus (Mr) of lime- and cement-stabilized cohesive soils were investigated by using Hydrite R (kaolinite) and sodium bentonite (montmorillonite) blends. It was found that Mr increases with decreasing deviator stress, increasing lime and cement content, and extended curing period. Moisture variations around optimum had little effect on Mr with higher lime contents. Multiple regression analyses and Student's t-tests indicated that all the factors investigated were significant and could be related to Mr by predictive regression equations. For a given stabilizer type and content, the low-plasticity clay (CL) soil produced the best results. The cement-stabilized CL soil normal cured for 28 days produced the highest Mr value. However, cement stabilization was not found to be very effective for the high-plasticity clay (CH) soil. Mineralogical composition has a marked effect on the Mr of lime and cement-stabilized cohesive soils. Kaolinitic CL soils work better than montmorillonitic CH soils with both lime and cement.

scholarly journals Anisotropic and age-dependent elastic material behavior of the human costal cartilage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matthias Weber ◽  
Markus Alexander Rothschild ◽  
Anja Niehoff
Keyword(s):  
Costal Cartilage ◽  
Indentation Test ◽  
Biomechanical Properties ◽  
Material Behavior ◽  
Cartilage Tissue ◽  
Elastic Behavior ◽  
Unconfined Compression ◽  
Unconfined Compression Test ◽  
Young’S Moduli ◽  
Age Related

AbstractCompared to articular cartilage, the biomechanical properties of costal cartilage have not yet been extensively explored. The research presented addresses this problem by studying for the first time the anisotropic elastic behavior of human costal cartilage. Samples were taken from 12 male and female cadavers and unconfined compression and indentation tests were performed in mediolateral and dorsoventral direction to determine Young’s Moduli EC for compression and Ei5%, Ei10% and Eimax at 5%, 10% and maximum strain for indentation. Furthermore, the crack direction of the unconfined compression samples was determined and histological samples of the cartilage tissue were examined with the picrosirius-polarization staining method. The tests revealed mean Young’s Moduli of EC = 32.9 ± 17.9 MPa (N = 10), Ei5% = 11.1 ± 5.6 MPa (N = 12), Ei10% = 13.3 ± 6.3 MPa (N = 12) and Eimax = 14.6 ± 6.6 MPa (N = 12). We found that the Young’s Moduli in the indentation test are clearly anisotropic with significant higher results in the mediolateral direction (all P = 0.002). In addition, a dependence of the crack direction of the compressed specimens on the load orientation was observed. Those findings were supported by the orientation of the structure of the collagen fibers determined in the histological examination. Also, a significant age-related elastic behavior of human costal cartilage could be shown with the unconfined compression test (P = 0.009) and the indentation test (P = 0.004), but no sex effect could be detected. Those results are helpful in the field of autologous grafts for rhinoplastic surgery and for the refinement of material parameters in Finite Element models e.g., for accident analyses with traumatic impact on the thorax.

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
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