Geotechnical Properties Of Soil Research Articles

Improving geotechnical properties of soil of hillock slope using crushed recycled concrete aggregates

With the massive expansion of urbanization worldwide, a huge volume of construction and demolition waste (CDW) generation has become a common issue along with CDW from controlled demolition and earthquakes, which causes a tremendous headache for environmentalists. Moreover, sliding and failure of the slope of hillocks, hills, roads, and earthen dams raise concerns for geotechnical engineers. Among the several methods of improving the geotechnical behaviour of soil of the slopes, this research utilized CDW-based recycled concrete aggregates (RCA) to improve slopes of two hillocks named GK and BH. The crushed RCA was applied in various percentages, 5–35 %, in the soil mass and as a circular column to observe the improvement of the soil's geotechnical properties that largely influence slope stability. RCA column, a sustainable alternative to the sand, stone, or other natural materials column, can work as a vertical drain with an improved permeability of slope geo-material to improve infiltration. The soil samples with 30 % RCA mixed and RCA columns inserted into the soil mass resulted in lower consolidation settlement, compressibility index, and higher shear strength parameters. Moreover, 30 % RCA column increased the permeability by 6 and 7-times for the hillocks GK and BH, respectively, which reduces the chance of excess pore water pressure (PWP) development that can trigger the failure of a slope. Improving soil properties with recycled concrete aggregates can be a sustainable way to solve weak soil and failure issues of low-permeable low-height natural hillocks.

Geotechnical Properties of Soils in Abu Al-Khasib City, Southern Iraq

To investigate some geotechnical characteristics of the soils in a chosen area of Abu Al-Khasib city, Basrah Governorate, southern Iraq, nine boreholes that range in depth from 10 to 32 meters were drilled. Based on the results of standard penetration tests and particle size analysis the Quaternary deposits, which extend vertically to a depth of 32 meters, are divided into 8 layers with varying bearing capacities depending on their consistency and compactness. These layers are Medium stiff brown lean clay, soft and very soft gray lean clay, medium stiff gray lean clay, stiff gray lean clay, medium denes gray silty sand, denes gray silty sand , hard gray clay-silt-sand mixture and very dense gray silty sand. The first layer's bearing capacity is 140 kN/m2, so it is considered as moderately adequate to support the isolated, strip,or raft shallow foundations of various light buildings in the study region, and soil improvement techniques, especially mechanical methods, are required. Different types of deep foundations such as piles and well foundations for heavy constructions must be extended to depths of 27 and 30 meters, which represents the 7th and 8th layers of high bearing capacity (640-760, 1100 kN/m2 respectively) in the study area. Inorganic clays with low plasticity are the most common classification for samples. The soils of the study area are considered highly compressible soils and have medium expansion degree which must be taken into account when constructing shallow foundations to minimize damage to buildings. The percentages of sulphates, total dissolved salts, organic content, and gypsum content are minimal and considered ineffective, whereas the percentages of carbonates and chlorides are high and affect the safety of shallow foundations. In the study site, the groundwater is around 0.5 m deep.

Soil Stabilization by Using Lime and Fly Ash at Ahirwadi

Abstract: Soil stabilization is a crucial aspect of civil engineering, particularly in the construction of infrastructure projects. This study investigates the effectiveness of lime and fly ash as soil stabilizers and their combined application for enhancing soil properties. The objective of this research is to evaluate the changes in the geotechnical properties of soil treated with lime and fly ash, including compressive strength, shear strength, and durability. In this experimental study, different proportions of lime and fly ash were mixed with the soil samples to determine the optimal combination that yields the highest improvement in soil characteristics. The laboratory tests conducted on the stabilized soil samples included compaction tests and unconfined compressive strength tests. The samples were cured for different periods to assess the long-term performance and durability of the stabilization technique. The results indicate that the addition of lime and fly ash significantly improves the soil's engineering properties. The lime effectively increases the soil's pH, reducing plasticity and improving workability. The fly ash, on the other hand, enhances the pozzolanic reactivity and improves the soil's strength and durability. The combination of lime and fly ash demonstrates synergistic effects, leading to further improvements in the stabilized soil's properties.

Evaluating the Undrained Shear Strength of Kalimati Soil Using Field Vane and Unconfined Compression Test; a Study on Applicability of Bjerrum’s Correction Factor

Rapid urbanization and geological challenges in Kathmandu have made it crucial to understand the geotechnical properties of the soil in the region. This study here focuses on the undrained shear strength of silty clay in Kalimati, Kathmandu, and investigates the applicability of Vane Shear tests and its parameters over other shear strength tests from other methods. Geotechnical investigations were carried out at three locations within the Kathmandu Engineering College premises and in-situ and laboratory tests were conducted on undisturbed and disturbed samples. Then the study compared the field vane shear strength, undrained strength from unconfined compression tests, and laboratory vane shear strength of the samples. For the field vane shear test the correction factor as suggested by Bjerrum was used and the results indicate that this method overestimates the shear strength in Kalimati soil, indicating no adjustment is necessary. The findings of this study have important implications for the design and construction of structures in the region, and contribute to a better understanding of the geotechnical properties of Kathmandu soil.

Seismic monitoring of strength in stabilized foundations by P-wave reflection and downhole geophysical logging for drill borehole core

Abstract Evaluating the subground properties during the initial stage of a construction of building is important in order to estimate the suitability of soil quality to the technical requirements of bearing capacity, resistance to stress, and strength. This study presented the evaluation of the geotechnical properties of soil intended for the construction of Max IV facility of Lund University, performed in fieldwork and laboratory. The in situ methods included drilling boreholes, core sampling and assessment, crosshole measurements, and borehole logging. The laboratory-based measurements were performed at Swedish Geotechnical Institute and combined seismic measurements of drill cores, determination of the uniaxial compressive strength (UCS), and examination of material property: sieve analysis and natural moisture content. UCS was evaluated with regard to velocities of elastic P-waves. The synchronous light test by X-ray diffraction was performed for qualitative analysis of mineral composition of samples. The study applied integrated approach of the diverse geophysical methods to solve practical tasks on the evaluation of foundation strength and geotechnical parameters. This study demonstrated the benefits of integrated seismic and geophysical methods applied to soil exploration in civil engineering for testing quality of foundation materials.

Effect Of Phytoremediation On The Geotechnical Properties Of Heavy Metal Contaminated Soil

<p>The accumulation of heavy metals in soils increases rapidly due to various natural processes. Heavy metal pollution changes the geotechnical properties of soil and poses a serious threat to human health and ecosystems, so soil pollution remediation is particularly important. Phytoremediation is an environmentally friendly approach that can be used as a successful mitigation measure to restore heavy metal-contaminated soils cost-effectively. The plants extract and remove elemental contaminants or reduce their bioavailability in soil and improve the geotechnical properties. In this study, we are conducting a pot experiment with Amaranthus by adding Zn salt as a contaminant and determining the rate of removal of metal.</p>

Geotechnical properties of cohesive soils used in the construction of subgrade for the development of the railways in the Azov-Black Sea region

This work is devoted to the determination and systematization of the properties of clay soils used in the construction of new railway tracks in order to develop the railway network in the Azov-Black Sea region of Russia. To this end, classification characteristics are determined by traditional laboratory methods, and the possibility of soil swelling under excessive moisture is estimated. In addition, the compressibility of soils is studied as the main factor ensuring the trouble-free operation of the subgrade of railways during their long-term operation. Soil samples for measurements were taken from open pits located near construction sites at an extended length of construction of 530 km. The new regression relations proposed in the work provide in some cases the accuracy of determining the soil characteristics close to the accuracy of laboratory tests. They may be in demand when monitoring the accuracy of laboratory tests of soil properties of other open pits and increasing the speed of pre-design surveys during further development of the railroad network in this region.

Enhancing Geotechnical Properties of Expansive Soil through Geopolymer Blended with Rice Husk Ash and Metakaolin: A Sustainable Approach for Soil Stabilization

Enhancing Geotechnical Properties of Expansive Soil through Geopolymer Blended with Rice Husk Ash and Metakaolin: A Sustainable Approach for Soil Stabilization

Enhancement of kaolin clay soil for civil engineering application using rice husk ash and sawdust ash geopolymer cements

These days, good quality road construction materials are scarce and their haulage to the construction site is expensive. When unsuitable materials are encountered during flexible pavement construction, the most technical and economical option is always to improve them to meet design standards. One of these deficient materials mostly encountered in tropical regions is kaolin clay soils. Cement and lime that are traditional deficient soil improvement agents are on high demand therefore have kept the cost of engineering construction financially high. Thus, the use of agricultural wastes such as sawdust and rice husk as alternative construction materials will considerably reduce the cost of construction and as well mitigate the environmental hazards caused by the wastes and cement production. This study investigated and compared the performance of rice husk ash (RHA) and sawdust ash (SDA) geopolymer cements in improving the geotechnical properties of kaolin clay soil used for flexible pavement construction. All laboratory experimental tests were carried out in accordance with British Standard (BS) 1377 and BS 1924 for natural and modified kaolin clay soil samples respectively. Soil samples were mixed with geopolymer cement at stepped concentrations of 0, 4, 8, 12, 16 and 20% by dry weight of soil. Results indicated that the plasticity index value of the natural kaolin clay of 18.52% was reduced to 7.24% at 20% RHA geopolymer cement content. The unconfined compressive strength of the natural soil was improved by 600 and 400 % by RHA and SDA geopolymer cements respectively. It was concluded that the use of up to 20% RHA and SDA geopolymer cements can efficiently and eco-friendly improve kaolin clay for flexible pavement foundation purpose.

Post-Wildfire Debris Flows in Montecito, California (USA): A Case Study and Empirically Based Debris Volume Estimation

Wildfires have a strong influence on various geotechnical and hydraulic properties of soils and sediments, which may become more vulnerable to landslides or debris flows. In the present study, a case investigation of the 2018 post-wildfire debris flows in Montecito, California, USA, was conducted, with a focus on the wildfire-affected areas and debris volume estimation. Significant debris were deposited around four major creeks, i.e., Montecito Creek, San Ysidro Creek, Buena Vista Creek, and Romero Creek in January, 2018, one month after the Thomas fire. Satellite images utilizing remote sensing techniques and geographic information system (GIS) data were analyzed to identify areas affected by the wildfire. Relevant data, including the slope, catchment area, and rainfall were used in two empirical models to estimate the debris volumes around the four creeks. As compared with field observation, each debris volume estimated with these empirical models was within the same order of magnitude. The debris volumes were generally underestimated when using the rainfall recorded at the Montecito Weather Station; the estimates considerably improved with the rainfall record from the Doulton Tunnel Station. The results showed that, overall, such empirical approaches are still of benefit for engineering practice, as they are capable of offering first-order approximations. The accuracy and availability of rainfall data are critical factors; the rainfall data in mountainous areas are generally higher than in the low lands, and consequently were more suitable for debris volume estimation in the present study, where the debris flows typically occurred in areas with steep slopes and at higher elevations.

Geotechnical properties of hazardous landfill leachate-contaminated sand

Many industrial activities dispose of their waste in the sand soil of the El-Khatatba region of Egypt. There is a need to reuse the site in building markets and shopping stores. Because it is difficult to obtain leachate from an open dumping site, we use hazardous landfill leachate (HLL) from an industrial waste landfill to identify changes in the geotechnical properties of soil. The HLL was obtained from Al-Nasreya Center, Alexandria, Egypt. This study, therefore, was directed to assess the effects of HLL on the geotechnical properties of the poor-graded sand (SP) soil. The natural sand was artificially mixed with HLL at different concentrations of 0%, 25%, 50%, 75%, and 100%. The results revealed that the permeability coefficient (k) of the natural sand decreased significantly from 1.28 × 10−2 to 0.8 × 10−2 cm/s when HLL concentration increased to 100%. Similarly, HLL contamination obviously reduced the angle of internal friction (φ) of sand. The optimum moisture content (OMC) of the natural sand decreased from 12 to 10%. In contrast, the maximum dry unit weight (MDD) of the natural sand increased slightly from 18.33 to 18.9 kN/m3 due to the increase of HLL concentrations from 0 to 100%. The change in the sand structure was interpreted by detailed analyses using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Based on these findings, HLL was found to modify the geotechnical properties of the studied sand.

Laboratory Evaluation of the Improvement of Geotechnical Properties of Fine-grained Soil Stabilized with Plastic Bottle Ash

The first principle in construction works is to have resistant land to build a building. Soil improvement is one of the common methods of improving geotechnical properties and increasing the usability of soil materials. One of the ways to improve the properties of the soil and transform the land into a place where construction is possible is to modify the soil by using additives to it. The use of waste as a material to improve the physical properties of the soil has attracted the attention of researchers. Among these wastes, we can mention rubber wastes, which, in addition to the large volume they occupy, will also cause environmental pollution. In this article, the effect of adding plastic bottle ash on the Zetterberg range and paste properties, the California bearing ratio, and the resistance properties of clay mixed with sand has been investigated. The results of the laboratory tests obtained from this research show the improvement of soil properties by adding plastic bottle ash.

Viability of bulk utilization of granite sludge powder (GSP) to enhance the geotechnical behavior of expansive soil

Granite blocks are cut, ground, and polished in the processing industries to achieve the desired dimension and texture. As a by-product of this process, finely powdered granite sludge powder (GSP) is generated. Over the last few decades, extensive research has been conducted in the field of using various industrial by-products to enhance the geotechnical characteristics of poor soils, thereby benefiting both the environment and the economy. The current study seeks to determine whether granite sludge powder can improve the geotechnical properties of expansive soils and be reused in pavement applications. Thus, the effect of different concentrations of granite sludge powder (0%, 5%, 10%, 20%, 30%, and 40% of the dry weight of soil) on the index and engineering properties of black cotton (BC) soil is evaluated. The study reveals that, with addition of up to 40% granite sludge powder to untreated natural expansive soil reduced free swell, Atterberg limits, and optimum moisture content. Whereas the engineering properties such as UCS, dry density, and CBR improved with the addition of GSP up to 30% and reduced thereafter. The maximum CBR value of 19.8 was obtained at 30% GSP concentration relative to the weight of dry soil. According to the test results obtained, granite sludge powder up to 30% can improve expansive soils geotechnical properties and could be used in subgrade applications for low volume roads.

Effects of Domestic Sewage Sludge on Gypseous Soil's Geotechnical Properties

Effects of Domestic Sewage Sludge on Gypseous Soil's Geotechnical Properties

A critical appraisal on some geotechnical properties of soil stabilised with nano-additives

A critical appraisal on some geotechnical properties of soil stabilised with nano-additives

Changes in geotechnical properties of soil contaminated by methyl tertiary butyl ether (MTBE)

As an extensively used gasoline additive, methyl tertiary butyl ether (MTBE) can leak into the subsurface, and this not only damages the ecological environment but also affects the geotechnical characteristics of the soil. In this study, the geotechnical properties of MTBE-contaminated soil, such as the basic physical properties of strength, compressibility, hydraulic conductivity, leachability, electrical resistivity and microstructural characteristics, are comprehensively investigated. The results show that the Atterberg limits consistently decrease with increasing MTBE content in the soil. As the MTBE content increases from 0 to 10%, the specific surface area of the soil decreases by 28%, the sand content increases by 22%, and the clay and silt contents decrease by 3 and 18%, respectively. The soil compression index, hydraulic conductivity, leached MTBE concentration and electrical resistivity increase, while the unconfined compressive strength (UCS) decreases, with increasing MTBE content. Microstructural analysis shows that increasing the MTBE content results in mineralogical alterations that decrease the illite and kaolinite content of the soil. The aggregation and flocculated structures can be detected by an increase in the number and size of inter-aggregate pores. In addition, the electrical resistivity of the contaminated soil is used to assess the geotechnical properties of the MTBE-contaminated soil based on well-established empirical relations.

Field experimentation of bio-cementation using low-cost cementation media for preservation of slope surface

Microbial induced carbonate precipitation (MICP) is a promising bio-cementation method that involves ureolytic bacteria to improve the geotechnical properties of soil. The laboratory-scale studies carried out in the recent past showed that the MICP can be a potential alternative for slope surface preservation. However, the use of analytical-grade chemicals makes this method too expensive, limiting the applicability of the method especially when implicated at field-scale. The purpose of this research work was to assess the effectiveness of using inexpensive low-grade chemicals for the in-situ stabilization of slope surface. Two test plots were established at the project site (Hokkaido expressway slope, Japan) and subjected to MICP treatment via surficial spraying. One was treated using the cementation media formulated by low-grade chemicals (inclusive of fertilizer urea, snow-melting agent and beer-yeast), while the typical analytical-grade media was used to treat the other plot. After 20 days of treatment, the treated slope surfaces were evaluated by surface strength, CaCO3 content, scanning electron microscopy, energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The outcomes indicated that the surface was significantly improved by low-grade chemicals; a stiff surface layer was desirably formed to the depth of 5 – 10 cm with the surface strength and CaCO3 content in the ranges of 0.14 – 1.02 MPa and 0.56 – 3.7%, respectively. The results are compared and discussed, and the challenges in the use of low-grade chemicals are pointed out for the way forward. Cost analysis disclosed that the material cost of the cementation media was reduced by around thirty-seven-fold (by 97%) compared to the analytical-grade media. While demonstrating the potential use of low-grade chemicals, the field-scale experiment could contribute to narrow down the gap between the present-state and real-scale deployment of MICP technology.

Mechanism and Engineering Characteristics of Expansive Soil Reinforced by Industrial Solid Waste: A Review

Expansive soils exhibit detrimental swelling and shrinking characteristics in response to variations in water content, posing a threat to engineering safety. Utilizing industrial solid waste for improving the engineering properties of expansive soil presents a promising solution due to its low pollution and high recoverability. This paper reviews the progress of research on various industrial solid wastes in stabilizing expansive soil. The review comprehensively discusses the microscopic characteristics and mechanism of industrial solid waste-stabilized soils, as well as their impact on the compressive strength, shear, compaction characteristics, consistency, swelling and shrinkage properties, and durability of expansive soils. The addition of appropriate curing agents or the combination with other stabilizing materials can enhance the strength of expansive soil, mitigate volume changes, and improve the durability and stability of expansive soils. The mechanisms of stabilization of expansive soils by industrial solid waste involve cation exchange, flocculation-agglomeration, pozzolanic reaction, and carbonation. Additionally, microscopic characterization analysis reveals that the formation of C-S-H and C-A-H is the primary contributor to the improvement of soil geotechnical properties.

Investigation the effect of geotextiles on the absorption of oil contamination and soil geotechnical properties

Oil-contaminated soil is detrimental to the ecosystem. There are various methods for purifying and controlling oil-contaminated soil. Among these, the use of oil absorbent geotextiles is considered a new method, and its performance requires more research. The separating by geotextiles has the advantages such as absence of chemicals in the separation process, less energy, simple control and implementation. This study presents an environmentally friendly sustainable solution using spacer geotextile layers to absorb crude oil and improve the geotechnical properties of contaminated soil. The variables include contamination percentage, number of fibrous substrate layers, soil overhead load pressure and duration of exposure to contaminated soil. The response variable is the internal friction coefficient of soil obtained from the direct shear test. By comparing soil samples containing geotextiles with samples without geotextiles, it was concluded that spacer geotextile layers could increase the internal friction coefficient of the soil and thus lead to improved soil properties. Increasing the number of geotextile layers, loading and the presence time of geotextile layers in the soil had increased the internal friction angle. But as the oil percentage in the soil increases, the internal friction angle of the soil decreases. Also, in this study, a linear regression model has been used to investigate the effect of existing parameters and the model was in good agreement with the experimental data.

Geotechnical properties of the South China Sea soft soil: a comparative study with the soils from Bohai Sea and Yellow Sea

Geotechnical properties of the South China Sea soft soil: a comparative study with the soils from Bohai Sea and Yellow Sea