scholarly journals Comparison of Mechanical Behaviors of Loess Based on Two Different Modes of Oil Contamination

2021 ◽  
Author(s):  
Shibin Zhang ◽  
Rongjian Li ◽  
Lei Wang ◽  
Qiang Yang
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Oil Pollution ◽  
Oil Production ◽  
Compression Modulus ◽  
Oil Contamination ◽  
Dry Density ◽  
Compression Tests ◽  
Mechanical Behaviors ◽  
Production Areas

Abstract In loess oil-production areas, oil leakage not only contaminates the loess, but also changes its mechanical properties. This study aimed to evaluate the effect of diesel oil contamination on mechanical behaviors of loess though extensive laboratory tests conducted on loess with different oil contents (0% to 16%) and dry densities (1.35, 1.45, and 1.55 g/cm3). Two different modes of oil contamination were proposed and applied in compression tests, direct shear tests and unconfined compressive strength tests to study the compressibility and strength characteristics of diesel-contaminated loess. Results show that oil-contamination modes have certain effects on the mechanical behaviors of loess. Under the first mode of oil contamination, compared with clean loess, the compressibility of contaminated loess increases and its unconfined compressive strength and shear strength all decrease. The compression modulus, friction angle, unconfined compressive strength of diesel-contaminated loess using the second mode of oil contamination are larger than those in the first mode of oil contamination at the same oil content and dry density. Understanding these effects of oil pollution can significantly guide soil and environment-remediation activities in oil-production areas.

scholarly journals Effects of Oil Contamination on the Physical-Mechanical Behavior of Loess and Its Mechanism Analysis

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Shibin Zhang ◽  
Rongjian Li ◽  
Weishi Bai ◽  
Qiang Yang
Keyword(s):  
Compressive Strength ◽  
Mechanical Behavior ◽  
Unconfined Compressive Strength ◽  
Oil Content ◽  
Compression Modulus ◽  
Diesel Oil ◽  
Theory And Practice ◽  
Dry Density ◽  
Mechanism Analysis ◽  
Water Contents

Oil leakage will not only pollute the soil but also change its physical-mechanical behavior, and loess has complex properties in the environment of oil presence. Artificial loess contaminated by diesel oil is collected as the research object. The physical and mechanical properties of clean loess and contaminated loess, including liquid and plastic limits, permeability, compression properties, and compressive strength characteristics, are estimated through a series of laboratory tests under different oil contents, water contents, and dry densities. Results show that liquid limits, plastic limits, and permeability coefficient of diesel-contaminated loess decrease with the increase of oil content. The compression modulus and compressive strength of diesel-contaminated loess increase with the increase of dry density at the same oil content. Adding diesel oil, the change law of the unconfined compressive strength of contaminated loess is opposite at the two different water contents. The variation of the compression modulus and unconfined compressive strength of diesel oil-contaminated loess is basically identical at the same condition. The findings of this study would be expected to bridge the gap between theory and practice in treatment and remediation of contaminated soil in the region of oil production.

scholarly journals Compression and Strain Predictive Models in Non-Structural Recycled Concretes Made from Construction and Demolition Wastes

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3177
Author(s):  
Evelio Teijón-López-Zuazo ◽  
Jorge López-Rebollo ◽  
Luis Javier Sánchez-Aparicio ◽  
Roberto Garcia-Martín ◽  
Diego Gonzalez-Aguilera
Keyword(s):  
Compressive Strength ◽  
Predictive Models ◽  
Unconfined Compressive Strength ◽  
Image Correlation ◽  
Peak Strain ◽  
Compression Tests ◽  
Maximum Peak ◽  
3D Digital Image Correlation ◽  
Granulometric Analysis ◽  
Physical And Chemical

This work aims to investigate different predictive models for estimating the unconfined compressive strength and the maximum peak strain of non-structural recycled concretes made up by ceramic and concrete wastes. The extensive experimental campaign carried out during this research includes granulometric analysis, physical and chemical analysis, and compression tests along with the use of the 3D digital image correlation as a method to estimate the maximum peak strain. The results obtained show that it is possible to accurately estimate the unconfined compressive strength for both types of concretes, as well as the maximum peak strain of concretes made up by ceramic waste. The peak strain for mixtures with concrete waste shows lower correlation values.

scholarly journals Characterization and Comparison Research on Composite of Alluvial Clayey Soil Modified with Fine Aggregates of Construction Waste and Fly Ash

2021 ◽  
Vol 28 (1) ◽  
pp. 83-95
Author(s):  
Qu Jili ◽  
Wang Junfeng ◽  
Batugin Andrian ◽  
Zhu Hao
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Clayey Soil ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Construction Waste ◽  
Comparison Research ◽  
Fine Aggregates ◽  
Optimum Water Content

Abstract Fine aggregates of construction waste and fly ash were selected as additives to modify the characteristics of Shanghai clayey soil as a composite. The laboratory tests on consistency index, maximum dry density, and unconfined compressive strength were carried out mainly for the purpose of comparing the modifying effect on the composite from fine aggregates of construction waste with that from fly ash. It is mainly concluded from test results that the liquid and plastic limit of the composites increase with the content of two additives. But their maximum dry density all decreases with the additive content. However, fine aggregates of construction waste can increase the optimum water content of the composites, while fly ash on the contrary. Finally, although the two additive all can increase the unconfined compressive strength of composites, fly ash has better effect. The current conclusions are also compared with previous studies, which indicates that the current research results are not completely the same as those from other researchers.

Experimental study on strength of cement stabilized clay

2005 ◽  
Vol 3 (2) ◽  
pp. 116-126 ◽  
Author(s):  
Woo‐Sik Kim ◽  
Nguyen Minh Tam ◽  
Du‐Hwoe Jung
Keyword(s):  
Compressive Strength ◽  
Soil Type ◽  
Unconfined Compressive Strength ◽  
Weight Ratio ◽  
Dry Weight ◽  
Strength Characteristics ◽  
Curing Time ◽  
Compression Tests ◽  
Soil Cement ◽  
Mixing Method

This paper describes the effect of factors on the strength characteristics of cement treated clay from laboratory tests performed on cement mixed clay specimens. It is considered that several factors such as soil type, sample preparing method, quantity of binder, curing time, etc. can have an effect on strength characteristics of cement stabilized clay. A series of unconfined compression tests have been performed on samples prepared with different conditions. The results indicated that soil type, mixing method, curing time, dry weight ratio of cement to clay (Aw), and water‐clay to cement (wc/c) ratio were main factors which can have an influence on unconfined compressive strength, modulus of elasticity, and failure strain of cement stabilized clay. Unconfined compressive strength of soil‐cement samples prepared from dry mixing method was higher than those prepared from wet mixing method.

scholarly journals The Effect of Polymer-Cement Stabilization on the Unconfined Compressive Strength of Liquefiable Soils

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Ateş
Keyword(s):  
Compressive Strength ◽  
Compression Strength ◽  
Unconfined Compressive Strength ◽  
Soil Stabilization ◽  
Sandy Soils ◽  
Pulse Velocity ◽  
Unit Weight ◽  
Unconfined Compression Strength ◽  
Compression Tests ◽  
Unconfined Compression

Soil stabilization has been widely used as an alternative to substitute the lack of suitable material on site. The use of nontraditional chemical stabilizers in soil improvement is growing daily. In this study a laboratory experiment was conducted to evaluate the effects of waterborne polymer on unconfined compression strength and to study the effect of cement grout on pre-venting of liquefiable sandy soils. The laboratory tests were performed including grain size of sandy soil, unit weight, ultrasonic pulse velocity, and unconfined compressive strength test. The sand and various amounts of polymer (1%, 2%, 3%, and 4%) and cement (10%, 20%, 30%, and 40%) were mixed with all of them into dough using mechanical kneader in laboratory conditions. Grouting experiment is performed with a cylindrical mould of  mm. The samples were subjected to unconfined compression tests to determine their strength after 7 and 14 days of curing. The results of the tests indicated that the waterborne polymer significantly improved the unconfined compression strength of sandy soils which have susceptibility of liquefaction.

Influence of Curing Pressure on Unconfined Compressive Strength of Cemented Clay

2018 ◽  
Vol 928 ◽  
pp. 263-268 ◽  
Author(s):  
Anuchit Uchaipichat
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Cement Content ◽  
Soft Clay ◽  
Peak Stress ◽  
Confining Pressure ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Soil Cement ◽  
Curing Pressure

The soil-cement columns are generally installed and cured in the soft clay layers under confining pressure. The strength of the soil-cement columns may be influenced by confining pressure during curing period. In this study, the main objective was to study the influence of curing pressure on unconfined compressive strength of cemented clay. A series of unconfined compression tests was performed on a cement admixed clay sample cured under pressure values of 0 kPa (atmospheric pressure), 25kPa, 50kPa and 100 kPa using a typical unconfined compression equipment. The test samples with values of cement content of 0.5, 1.0 and 2.0 percent were cured for 28 days.The stress-strain curves obtained from all tests show a peak value of stress. The unconfined compressive strength or peak stress obviously increased with increasing cement content for all curing pressure conditions. It can be observed that the strength of samples gradually increased with curing pressure for cement content of 0.5 percent. For cement contents of 1.0 and 2.0 percent, the strengths of samples cured under pressures of 25 kPa dramatically increased from the strength of samples cured without pressure (0 kPa), however, the strengths of samples for curing pressures of 25, 50 and 100 kPa were not clearly different.

scholarly journals The Effect of Oil Contamination on some Geotechnical Properties of West Qurna Oilfield Soils at Basrah, Southern Iraq

2021 ◽  
Vol 54 (2B) ◽  
pp. 76-84
Author(s):  
Ahmed K. Al-Nimah
Keyword(s):  
Compressive Strength ◽  
Moisture Content ◽  
Crude Oil ◽  
Unconfined Compressive Strength ◽  
Liquid Limit ◽  
Geotechnical Properties ◽  
Oil Contamination ◽  
The West ◽  
Coefficient Of Consolidation ◽  
Clayey Silt

Oil contamination in soils causes several geotechnical problems that must be considered during construction. The contamination occurs due to oil seepage which could happen during oil explorations and production processes or oil transportation. The site of West Qurna oilfield in Basrah was selected for this study because it has witnessed oil seepages many times. In order to study the significant impact on geotechnical properties of soils in the West Qurna site, as uncontaminated bulk soil sample was taken at a depth of 1 m, and crude oil was added at weight ratios of 2, 4, 6, 8, and 10 %. Laboratory tests were performed on all samples; these tests included particle size distribution, moisture content, Atterberg’s limits, consolidation, unconfined compressive strength, and water absorption. The results show that soil at the West Qurna site is clayey silt with little sand and the moisture content is 29.21%. The values of liquid limit and plasticity index were gradually decreased, while the plastic limit was increased with increasing of crude oil in the soil of study. There was an increase in consolidation coefficients [compressive index, swelling index, pre-consolidation pressure, and coefficient of consolidation] with an increase in the percentages of crude oil in the soil. The results also show that there was a decrease in the values of unconfined compressive strength and absorption of water as the crude oil was increased in the soil.

scholarly journals Using Nanomaterials in Stabilization of Soil for Oil Infrastructures

2020 ◽  
Vol 10 (3) ◽  
pp. 36-53
Author(s):  
Dr. Zaid Hameed Majeed ◽  
Eng. Kadhim Jawad Aubais ◽  
Dr. Mohd Raihan Taha
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Soil Stabilization ◽  
Dry Weight ◽  
Environmental Benefits ◽  
Al2o3 Content ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Geotechnical Characteristics ◽  
Compressible Soil

The design foundations  of storage tanks for oil industry experiences significant problems due to the widespread occurrence of weak and compressible soil which resulted in foundation failure. In this study, soft soils were taken from two locations and mixed with three types of nanoparticles which were nano-alumina (nano Al2O3), nano-copper (nano CuO), and nano-magnesium (nano MgO). Nanomaterials were incorporated in small percentage (less than 1%) by dry weight of soil. The tested geotechnical characteristics included the water content, dry density, and the unconfined compressive strength. The results showed significant enhancements in the maximum dry density and unconfined compressive strength. The level of enhancement depended on the type of nanomaterials and the contents. Improved strength and hardening properties were shown with the utilization of nano CuO material in comparison to the soil samples with the other nanomaterials additions, with its optimum addition of 0.7% provided an increment rate of 662.7% while the optimum nano CuO which is about 1% showed a 532% increasing rate in the compressive strength of S1 soil. It was noted that the maximum dry density and unconfined compressive strength enhanced with the increase in the nanoparticles content until reaching a percentage in which the strength decreased. The optimum content of the nano MgO was 0.3% while the optimum nano Al2O3 content was about 0.3% for soil S1 and was about 0.1% for soil S2. The presence of nanomaterials in excessive contents caused agglomeration of particles which had negative influences on mechanical characteristics of the soils. Generally, the incorporation of finer particles like nanoparticles even with low amount would improve the geotechnical characteristics of soils with the consideration of the potential environmental benefits, these combined admixtures are intended to lower the cost and become a more sustainable and environmental alternative for soil stabilization

scholarly journals Influence of Lime for Enhancing Characteristics of Expansive Soils in Road Works

2021 ◽  
Vol 1197 (1) ◽  
pp. 012077
Author(s):  
K.S Chamberlin ◽  
M. Rama Rao
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Expansive Soils ◽  
Black Cotton Soil ◽  
Dry Density ◽  
Test Results ◽  
Lime Treatment ◽  
Maximum Dry Density ◽  
Slaked Lime ◽  
Black Cotton Soils

Abstract Expansive soils are found in black cotton soils, which swell or shrink in volume when presented to changes in moisture content. Lime treatment is exhaustively used to increment the properties of sensitive and fragile soils. One of the hugest clarifications behind using lime is to decline the developing presentation of the earth soil. The arrangement of extra safeguards improves the reaction of quicklime (CaO) with water, structures hydrated (slaked) lime (Ca (OH)2), and thus earth characteristics. The vast inadequacy of employing lime is growing the deficiency of lime offset earth. Following that, the goal of this study is to see how re-establishing time affects the geotechnical qualities of settled Black cotton soils with lime. These discoveries recommend that adding Lime as a stabilizer works on the strength of black cotton soil. Some of the characteristics of the soil likely to be increased by using stabilizer in this work are UCS (Unconfined Compressive Strength) at different curing periods (7,14,28 and 56 days), CBR (California Bearing Ratio) value at unsoaked and soaked and MDD (Maximum Dry Density) decrease at different lime percentages(%) like 2.4.6.8 and 10. The result showed here untreated soil got stabilized by using the stabilizer in certain extent In this adjustment various rates of cementitious material is added to black cotton soil and directed tests like plasticity, compaction, swell pressure, free swell index(FSI), Coefficient of permeability (k) and CBR(soaked and unsoaked) at various conditions like OMC,OMC+2% water and OMC+5% water, UCS (Unconfined Compressive Strength) was performed. From the test results, it is identified that the stabilization agent decreases plasticity and improves strength characteristics. Addition of stabilizing agent makes the black cotton soil to non-plastic, non-swelling and attains increase CBR values which are greater than 25% for a dosage of 10% lime at OMC but remaining OMC+2%water & OMC+5%water CBR values are not various much difference as per test results. With the addition of lime, the black cotton soil becomes non-plastic, non-swelling, and has high strengths. Treated soils are used as a development material, for example, a subgrade layer in the development of adaptable asphalt pavements for roads.

scholarly journals Strength Improvement of Weak Subgrade Soil Using Cement and Lime

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Anigilaje B Salahudeen ◽  
Ja’afar A Sadeeq
Keyword(s):  
Compressive Strength ◽  
Moisture Content ◽  
Unconfined Compressive Strength ◽  
Optimum Moisture Content ◽  
Atterberg Limits ◽  
California Bearing Ratio ◽  
Natural Soil ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Subgrade Soil

The study investigate the suitability of subgrade soil in Baure Local Government Area of Kastina State Nigeria for road construction. The strength properties of the  subgrade was improved using lime and cement. Several analysis including the particle size distribution, specific gravity, Atterberg limits, compaction characteristics, unconfined compressive strength and California bearing ratio tests were performed on natural and lime/cement treated soil samples in accordance with BS 1377 (1990) and BS 1924 (1990) respectively. Soil specimens were prepared by mixing the soil with lime and cement in steps of 0, 3, 6, and 9% by weight of dry soil in several percentage combinations. The Atterberg limits of the weak subgrade soils improved having a minimum plasticity index value of 5.70 % at 3%Lime/6%Cement contents. The maximum dry density (MDD) values obtained showed a significant improvement having a peak value of 1.66 kN/m3 at 9%Lime/9%Cement contents. Similarly, a minimum value of 18.50 % was observed for optimum moisture content at 9%Lime/9%Cement contents which is a desirable reduction from a value of 25.00 % for the natural soil. The unconfined compressive test value increased from 167.30 kN/m2 for the natural soil to 446.77 kN/m2 at 9%Lime/9%Cement contents 28 days curing period. Likewise, the soaked California bearing ratio values increased from 2.90 % for the natural soil to 83.90 % at 9%Lime/9%Cement contents. Generally, there were improvements in the engineering properties of the weak subgrade soil when treated with lime and cement. However, the peak UCS value of 446.77 kN/m2 fails to meet the recommended UCS value of 1710 KN/m2 specified by TRRL (1977) as a criterion for adequate stabilization using Ordinary Portland Cement.            Keywords: Weak subgrade soil, Lime, Cement, Atterberg limits, Maximum dry density, Optimum moisture content, Unconfined compressive strength, California bearing ratio

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