scholarly journals Unified Evaluation of Consolidation Parameters for Low to High Plastic Range of Cohesive Soils

2021 ◽  
Vol 40 (1) ◽  
pp. 93-103
Author(s):  
Zia ur Rehman State ◽  
Khalid Farooq ◽  
Hassan Mujtaba ◽  
Usama Khalid
Keyword(s):  
Cohesive Soil ◽  
Soil Samples ◽  
Engineering Properties ◽  
Cohesive Soils ◽  
High Plasticity ◽  
Index Properties ◽  
Undisturbed Soil ◽  
Index Compression ◽  
The Right ◽  
Consolidation Parameters

Knowing the engineering properties of geomaterials is imperative to make the right decision while designing and executing any geotechnical project. For the economical and safe geotechnical design, quick characterization of the compressibility properties of the cohesive soil is often desirable; these properties are indeed tedious to determine through actual tests. Therefore, correlating the consolidation parameters of the soils with its index properties has a great significance in the geotechnical engineering field. Several attempts have been made in the past to develop correlations between the consolidation parameters and index properties of the cohesive soils, within certain limitations. However, there is still a need to develop such correlations based on the extensive database, composing of unified plasticity range of soils, i.e., low to high plasticity. In the current study, 148 undisturbed soil specimens were obtained from different areas of Pakistan. Out of which 120 samples were utilized to develop correlations, and 28 samples were used to check the validity of the developed correlations. In order to enhance the index properties database, 30 more bentonite mixed soil samples were prepared and tested accordingly. Correlations to envisage different consolidation parameters such as compression index, compression ratio and coefficient of volume compressibility were developed using 150 cohesive soil samples of low to high plasticity. In addition, the performance of these developed correlations was verified on a set of 40 soil samples and compared with the performance of different correlations available in the literature. The percentage deviation in the prediction of compressibility characteristics through developed correlations in the present study was found to be very less, which endorsed the excellent reliability of the developed correlations.

scholarly journals Engineering Characterization of Subgrade Soils of Jimma Town, Ethiopia, for Roadway Design

Geosciences ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 94
Author(s):  
Alemineh Sorsa ◽  
Sanjaya Senadheera ◽  
Yoseph Birru
Keyword(s):  
Engineering Properties ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
High Plasticity ◽  
Soil Characterization ◽  
Engineering Structures ◽  
Undisturbed Soil ◽  
Subgrade Soil ◽  
Geotechnical Investigations ◽  
Jimma Town

Soils are naturally occurring materials that carry loads of civil engineering structures including roads and buildings. However, not all natural soils are suitable for such uses due to limited strength and instability under varying environmental conditions. A lack of adequate geotechnical investigations and soil characterization can result in the over-design of foundations, unexpected excavations to remove unsuitable soils, cost overruns, construction delays; and, contract disputes. In this research, an experimental plan was executed to determine the engineering properties of subgrade soil in Jimma Town in southwestern Ethiopia by using both disturbed and undisturbed soil samples. The plan included tests to determine the moisture content, specific gravity, grain-size analysis, Atterberg limits, compaction-density relationship, California Bearing Ratio (CBR), unconfined compression strength, and triaxial shear strength. X-ray diffraction (XRD) analysis was also conducted to determine the chemical composition of the soil. The soil characterization indicated that soft clay is the predominant subgrade soil type and that it has a very low load-bearing capacity, high plasticity, low strength and, high compressibility, which makes the soil unsuitable to serve as a highway subgrade without the help of soil improvement techniques.

Evaluation of liquefaction potential of foundation soils at Duncan Dam

1994 ◽  
Vol 31 (6) ◽  
pp. 951-966 ◽  
Author(s):  
V.S. Pillai ◽  
R.A. Stewart
Keyword(s):  
Engineering Properties ◽  
Soil Parameters ◽  
Confining Stress ◽  
Undisturbed Soil ◽  
Liquefaction Potential ◽  
Sand Liquefaction ◽  
Cyclic Resistance ◽  
And Performance ◽  
Design Earthquake ◽  
The Right

A comprehensive program of field, laboratory, and analytical investigations was carried out to evaluate the potential of liquefaction for the foundation soils at Duncan Dam. Duncan Dam was completed in 1967 under the Columbia River Treaty in southeastern British Columbia. The 39 m high zoned embankment dam is founded on a sequence of sands, silts, and gravels. Some of the foundation soils may liquefy during earthquake loading and this would affect the stability and performance of the dam. The liquefaction studies were carried out in two phases to characterize the engineering properties of the foundation soils and to assess its potential for triggering liquefaction using the total stress approach. This paper describes methods of assessment of liquefaction potential using soil parameters based on field penetration data (Seed's method) and laboratory testing of undisturbed soil samples obtained in situ after freezing the ground (Lab method) and presents the results of triggering analysis. Influence of confining stress (Kσ) and initial static shear stress (Kα) on liquefaction were investigated and site-specific Kσ and Kα curves were developed.For the design earthquake (M 6.5, PGA = 0.12g) both the Lab method and Seed's method predict a significant extent of liquefaction of the foundation soils under the downstream slope in the right half of the dam. Key words : sand, liquefaction, confining stress, density, cyclic resistance ratio.

scholarly journals GEOTECHNICAL INVESTIGATION OF PAVEMENT FAILURE; CAUSES AND INHERENT SOLUTIONS FOR SUSTAINABLE HIGHWAY CONSTRUCTION IN SUB-SAHARAN AFRICA

2020 ◽  
Vol 35 (4) ◽  
pp. 103-114
Author(s):  
Omowumi Ademila ◽  
Abel Idowu Olayinka
Keyword(s):  
Clayey Soil ◽  
Triaxial Compression ◽  
Road Construction ◽  
Liquid Limit ◽  
Soil Samples ◽  
Sub Saharan Africa ◽  
High Plasticity ◽  
Coefficient Of Consolidation ◽  
Geological Investigation ◽  
Undisturbed Soil

Engineering geological investigation of some unstable and stable sections of the Ibadan-Iwo-Osogbo highway was undertaken to unravel the intrinsic reasons responsible for continuous pavement failure along this road. Eighty disturbed and forty undisturbed soil samples were collected at different depths from twenty test pits of six selected failed sections (FS) and two stable sections (SS). Road construction analysis was done on these soil samples using standard methods. Liquid limit (22 - 64% and 32 - 40%), plasticity index (13 - 41% and 12 - 18%) and percentage fines (47 - 59% and 32 - 41%) indicated fair to poor and fair to good subgrade materials of FS and SS respectively. Medium to high plasticity and high clay content of soils of FS are indicative that the soils possess medium to high swelling potential. The activity of clay in soils of FS was approximately 0.3 – 1.2 and classified as inactive to normal clay. High linear shrinkage (> 10%), low compacted density and predominance of fines in soils of FS caused the instability. Exposure to excessive moisture led to strength reduction of the soils. Triaxial compression showed cohesion (72.6 - 127.0 kN/m2) and internal friction (12.7° - 33.3°) indicating moderate to good shearing strength of the soils. A coefficient of compressibility of 0.1 – 0.5 kN/m2 indicated incompetency of the soils for road construction and the coefficient of consolidation was 0.01 – 0.30 m2 /year. The subsoil of the FS is impervious with a relatively low coefficient of permeability, indicative high saturation in the region. Thus, the pavement failure was caused by water absorbing clayey soil, poor geotechnical parameters of the soils and a poor drainage network.

scholarly journals KETERDAPATAN MINERAL LEMPUNG SMEKTIT YANG MEMPUNYAI SIFAT PLASTISITAS TINGGI DI PERAIRAN CIREBON, JAWA BARAT

2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Purnomo Raharjo ◽  
Lili Sarmili
Keyword(s):  
Grain Size ◽  
Water Content ◽  
Clay Minerals ◽  
Plasticity Index ◽  
Engineering Properties ◽  
High Plasticity ◽  
Mineral Analysis ◽  
Undisturbed Soil ◽  
Very High

Salah satu masalah dalam pembangunan infrastruktur di atas tanah lempung adalah sifatnya  yang mengembang (swelling). Tujuan penelitian adalah untuk mengetahui sifat fisik dan keteknikan tanah lempung di perairan Cirebon. Metode penelitian meliputi pemboran, besar butir, analisis mineral dan uji Atterberg. Hasil analisis ukuran butir dari contoh tanah tidak terganggu didominasi oleh lempung, sedangkan mineral lempungnya menunjukkan jenis smektit yang lebih banyak dari pada kaolinit. Kaolinit dan montmorilonit  mempunyai kadar air yang tinggi. Nilai plastisitasnya tinggi sampai sangat tinggi dengan nilai aktifitas di atas 0,5. Berdasarkan hasil uji Atterberg plastisitas Index lempung  dengan nilai >17 dapat dikategorikan bersifat plastisitas tinggi dan kompak (High Plasticity and cohesive). Kata kunci : Mineral smektit, plastisitas tinggi, uji Atterberg, analisis mineral lempung, perairan Cirebon.One of the problems in the construction of infrastructure on top of clay is that it is expanding (swelling). The research objective was to determine the physical and engineering properties of clay in the waters of Cirebon. Methods of research include drilling, grain size analyses, mineral analysis and Atterberg test. The results of the analysis of the grain size of the sample undisturbed soil dominated by clay which are indicated and dominated by smectite rather than kaolinite. Kaolinite and monmorilonite are high in water content. The plasticity value  is high to very high with activity value above 0.5. Based on the results of Atterberg test, clay plasticity index with values >17 can be considered to be of high plasticity and compact (High Plasticity and cohesive).Keywords: smectite minerals, high plasticity, Atterberg test, clay minerals analysis, Cirebon waters.

scholarly journals ENGINEERING PROPERTIES OF SEA FLOOR SEDIMENTS FROM LA JOLLA CANYON

1972 ◽  
Vol 1 (13) ◽  
pp. 82
Author(s):  
Iraj Noorany ◽  
Robert A. Zinser
Keyword(s):  
Grain Size ◽  
Underwater Vehicle ◽  
Engineering Properties ◽  
High Plasticity ◽  
Index Properties ◽  
Near Surface ◽  
Sea Floor ◽  
Size Index ◽  
La Jolla

Near surface sea floor sediments were obtained "by the tracked underwater •vehicle RUM from four locations on the floor of the La Jolla Canyon. The sediments were clayey silts of high plasticity. The engineering properties of the sediments, including grain size, index properties, strength and compressibility, were determined.

Estimating overconsolidation ratio (OCR) in structured and unstructured cohesive soil with field vane tests referencing soil index properties

2021 ◽  
Vol 58 (1) ◽  
pp. 125-141
Author(s):  
Steven R. Saye ◽  
Bryan P. Kumm ◽  
Alan J. Lutenegger
Keyword(s):  
Organic Matter ◽  
Soil Type ◽  
Organic Matter Content ◽  
Cohesive Soil ◽  
Matter Content ◽  
Engineering Properties ◽  
Cohesive Soils ◽  
Geologic History ◽  
Testing Procedures ◽  
Overconsolidation Ratio

Estimation of the preconsolidation stress and overconsolidation ratio (OCR) in uniform cohesive soils using a field vane is variably impacted by the combined effects of soil type and plasticity, geologic history, structured vs. unstructured behavior, and the presence of sand or organic matter. Published empirical correlations for cohesive soils consider the effects of soil type and plasticity, but significant variability can occur with changes in soil structure and organic matter content for specific instances. The adaption of the “stress history and normalized soil engineering properties” (SHANSEP) format improves the characterization of overconsolidated soils using field vane tests by applying a proposed empirical approach to identify structured soils from unstructured soils and updating the SHANSEP-based approach to separately evaluate structured and unstructured soils. Validation of the correlation coefficients for individual projects will be needed as the approach is applied to new geologic materials and with potentially different field vane equipment and laboratory testing procedures used to characterize the soils. This additional testing provides an opportunity to improve the correlations for specific conditions and reduce the variability in the OCR assessments.

Studies on soil contamination due to used motor oil and its remediation

2009 ◽  
Vol 46 (9) ◽  
pp. 1077-1083 ◽  
Author(s):  
S. K. Singh ◽  
R. K. Srivastava ◽  
Siby John
Keyword(s):  
Sodium Dodecyl ◽  
Dry Weight ◽  
Soil Samples ◽  
Geotechnical Properties ◽  
Engineering Properties ◽  
Experimental Program ◽  
High Plasticity ◽  
Motor Oil ◽  
Used Motor Oil ◽  
Study Laboratory

An experimental program was undertaken to evaluate the changes in behaviour of soils due to interaction with used motor oil (U.M.O) followed by their remediation. Different types of soils classified as clay with low plasticity (CL), clay with high plasticity (CH), and poorly graded sand (SP) were used for the study. Laboratory studies were conducted on virgin (uncontaminated) soil samples and soil samples simulated to varying degrees of contamination (i.e., 3%, 6%, and 9% by dry weight of soil) to compare the geotechnical properties before and after contamination. The engineering properties altered due to contamination. Surfactant (sodium dodecyl sulphate (SDS)) enhanced washing was employed to decontaminate the soils. It was observed that the original geotechnical properties of soils could be almost restored (variation ranging from 0 to 12%) upon decontamination with SDS at an optimum dosage.

scholarly journals Compressibility behaviour of remoulded, fine-grained soils and correlation with index properties

2000 ◽  
Vol 37 (3) ◽  
pp. 712-722 ◽  
Author(s):  
A Sridharan ◽  
H B Nagaraj
Keyword(s):  
Liquid Limit ◽  
Plasticity Index ◽  
Engineering Properties ◽  
Test Results ◽  
Index Properties ◽  
Initial Water ◽  
Fine Grained ◽  
Wide Range ◽  
The Relationship ◽  
Water Contents

Correlating engineering properties with index properties has assumed greater significance in the recent past in the field of geotechnical engineering. Although attempts have been made in the past to correlate compressibility with various index properties individually, all the properties affecting compressibility behaviour have not been considered together in any single study to examine which index property of the soil correlates best with compressibility behaviour, especially within a set of test results. In the present study, 10 soils covering a sufficiently wide range of liquid limit, plastic limit, and shrinkage limit were selected and conventional consolidation tests were carried out starting with their initial water contents almost equal to their respective liquid limits. The compressibility behaviour is vastly different for pairs of soils having nearly the same liquid limit, but different plasticity characteristics. The relationship between void ratio and consolidation pressure is more closely related to the shrinkage index (shrinkage index = liquid limit - shrinkage limit) than to the plasticity index. Wide variations are seen with the liquid limit. For the soils investigated, the compression index relates better with the shrinkage index than with the plasticity index or liquid limit.Key words: Atterberg limits, classification, clays, compressibility, laboratory tests.

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.

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