Clayey Soils Research Articles

Effect of leachate and used motor oil on the geotechnical and mechanical characteristics of soils with different mineralogy under different moisture conditions

ABSTRACT In order to evaluate the geotechnical characteristics of four types of fine-grained clayey soil, including clay with low plasticity (CL), calcium bentonite (CB), sodium bentonite (SB), and a mixture of 50% CL and 50% SB (CL-SB) from the effect of water, leachate and used motor oil (UMO) was used. Unconfined compressive strength (UCS), indirect tensile strength (ITS), standard compaction, Atterberg limit, and free swelling tests are performed. This results showed that the PI of SB, CB, CL, and CL-SB soils with leachate is 43, 25, 10, and 33% higher than water, respectively. The PI of SB, CB, CL, and CL-SB soils with UMO is 72, 66, 12, and 43% lower than water due to the low dielectric constant. Adding leachate compared to water caused a decrease in maximum dry density (MDD) for CL, CL-SB, SB, and CB by 2.6%, 4%, 6%, and 4.5%, respectively. Also, adding leachate and UMO reduces UCS and ITS of all soils. Due to SB soil’s high cation exchange capacity, the changes in its mechanical and geotechnical characteristics were higher than in other soils. Finally, the increase in soil moisture during the sample construction decreased the soil strength due to the addition of leachate and UMO.

Experimental investigation on the desiccation cracking process in date palm fiber reinforced clayey soil using digital image correlation

This paper presents an experimental study that aims to enhance the cracking resistance of clay soil. Laboratory tests were performed in order to assess the effect of fiber content and length on the desiccation cracking of clay soil. During these tests, a digital image acquisition system was used to depict the development and spread of cracks. The results were analyzed using the DIC digital image correlation technique for the full-strain obtaining and image processing analysis for the crack feature measurements. The results show that date palm fibers have a considerable impact on the wide spread of cracks in clay soil during desiccation, in addition to their area and width. The DIC approach was useful for monitoring the displacement evolution and strain field detection on the surface of the specimen. The addition of fibers slows the water evaporation rate of the specimens. Optimum crack reduction ratio of about 47% was found in fiber-reinforced clay with 0.75% fiber content at 10 mm fiber length.

Performance Evaluation of Clayey Soil Considering Impact of Lime During Electrokinetic Consolidation

Performance Evaluation of Clayey Soil Considering Impact of Lime During Electrokinetic Consolidation

Experimental Study on the Corrosion of Fulvic Acid to Cement-Soil and Its Microstructures in the Peat Soil Environment

In underground engineering, cement-soil reinforcement beneath a peat soil environment is a significant challenge. To investigate the corrosiveness of fulvic acid on cement-soil and its micro and fine structure changes under the peat soil environment (PSE), an experiment was conducted to prepare peat soil by mixing humic acid (HA) into an alluvial clayey soil and then adding cement to make a cement-soil specimen, which was soaked in a fulvic acid (FA) solution and deionized water to simulate the different working of the cement-soil. The experiment was carried out by a scanning electron microscopy (SEM) test, mercury intrusion porosimetry (MIP) test, pore (particle) and fracture image recognition and analysis (PCAS), and unconfined compressive strength (UCS) test on cement-soil with soaking time as the variation factor. The results show that: In the deionized water environment, the structural characteristics of the cement-soil exhibited a gradual enhancement followed by a slight weakening. Conversely, when placed in a peat soil environment, the strength of the cement-soil initially increased at a slow rate due to the gelling and filling impact of fulvic acid. However, in the later stages, the corrosive influence of fulvic acid became dominant. This led to an enlargement of the pore space within the cement-soil, resulting in a gradual deterioration of its structure. Consequently, the strength of the cement-soil displayed a pattern of slow initial increase followed by a rapid decrease.

Applying Plaxis 3D To Model Leaking Water Supply Pipe Causing Sandy Soil Erosion and Sinkhole Formation

Water supply pipes in urban areas are always buried underground. There are many causes of pipe breakage and leakage of high-pressure water from the pipe to the outside, the flow of water has a pressure higher than the soil erosion limit, causing the soil structure to be broken, eroding the surrounding clayey sandy soil. The development of the eroded clayey sandy soil area, which expands over time, is the cause of the formation of a sinkhole under the road, which is dangerous for vehicles and people. In this study, the authors apply finite element software (Plaxis 3D) to model water supply pipelines in sandy soil in case the pipeline leaks water with different pressures. Analytical models indicate that sinkhole formation is dependent on the extent of the erosive clayey sandy soil, which is related to the extent and direction of the pressurized water jet, and the depth of the pipe.

Experimental study on stabilization of clayey soil using agricultural and industrial waste

The purpose of this experimental study is intended to explore if SCBA (Sugarcane Bagasse Ash and Marble Dust) may help clayey soil stabilize and hence to overcome environmental pollution. BA (Bagasse Ash) is the waste produced by the sugar factory after the processing of sugarcane. Factories dispose of the BA in the landfills which affect the environment, one of the reasons to do this experiment is to make use of this waste product for a sustainable environment. At the time of marble manufacturing, marble dust is produced. The soil around a building's foundation plays an important influence on its stability. As a result, the engineer should have a complete understanding of the components that influence soil behaviour and can be affected by the soil stabilization process. The soil is treated with bagasse ash and a partial replacement of marble dust (13 percent, 17 percent, and 21 percent) (10 percent, 12 percent, and 14 percent). In this study, a large number of specimens were made, and then the test specimens were analyzed for compaction characteristics and CBR. It was discovered that an increase in MD (Marble Dust) and BA increased the compaction and CBR characteristics to a certain extent.

Comparison of Unsaturated Hydraulic Conductivity Calculated by Jackson Equation and Van Genuchten Equation for Three Different Soils in Their Gypsum Content and Treated with Polymer and Peatmoss

An experiment was conducted to compare the unsaturated hydraulic conductivity (K) calculated by Jackson equation and van Genuchten equation for soils different in gypsum content and treated with some soil conditioners. Two soils were used, gypsiferous soil (410 gm kg-1gypsium) and clayey soil (435 gm kg-1 clay), were mixed in three levels 0, 50, and 100%. The soils were treated with peat moss 0 and1%, polymer,0,1.and 2% and without addition. Then, were packed into plastic tubes 5 cm diameter and 25 cm in height at bulk density of 1.3 Mg m-3 and were exposed to three wetting / drying cycles. The unsaturated hydraulic conductivity was calculated from (Jackson equation, and van Genuchten equation. the results showed good agreement between K values measu dy using Jackson and van Genuchten equation using RETC program. The relationship between K and θ and percentages of gypsum is a positive and between K and ψ an inverse relationship. The value of K increased from 81.7 cm. day-1 to 137.8 cm. day-1 when the percentage of gypsum was increased from 46 to 410 g kg-1 consecutively for soil in treated with conditioners and within minor tension limits approaching zero. The K values decreased when the soil was treated with peatmoss and polymer, and the most effective treatment in reducing the K values was a mixture of (2% polymer + 1% peatmoss). The K values remained close to zero with medium to high tensions and also with medium to low θ, and it did not increase to an effective degree except when θ approached its upper limits and with low tensions, and its increase was exponential within these ranges.

Feasibility for the Recovery of Excavated Soils in Compressed Earth Blocks as a Sustainable Building Material

Soil is continuously excavated for development activities in urban and rural areas and treated as waste. This study investigates the characteristics of urban soils excavated from earthworks of buildings in the Brittany region of France for their perspective reuse in earthen construction materials to valorize soil waste and provide a sustainable building material locally. Excavated soil from earthwork activities was taken from the Brittany region of France from three different locations. Soil suitability for compressed earth blocks was investigated based on their granulometry, consistency limits, and mineralogy. Finally, compressed earth blocks with dimensions of 4 × 4 × 16 cm3 were manufactured with different formulations and compacted dynamically. Flexural and compressive strength tests were performed on bricks to observe their mechanical behavior. Grain size analysis of soil samples shows that the percentage of clay in the landfill stockpile of excavated soils varies between 13% and 16%, while at some local sites, the percentage of clay goes up to 57%. The grain size of soils varies from the recommended zone. The plasticity of soil samples ranges from 17.3% to 20.4%. The plasticity index and clay content of the soil show that these soils are inactive clays with a lesser possibility of swelling and shrinkage. Mineralogical analysis of soil shows the absence of water-sensitive clay minerals, while quartz, kaolinite, and illite are major minerals present in soils. Linear shrinkage in bricks ranges from 0.6% to 2.2% and is considerably higher for clayey soils. Mechanical testing of earth bricks shows that the compressive strength of earth blocks ranges from 0.92 MPa to 2.22 MPa while the flexural strength ranges from 0.25 to 0.74 MPa. A mixture of sandy and clayey soils shows good strength due to improved granulometry. Earth bricks with soils from some stockpiles, excavation sites, and soil mixture show compressive strength higher than 1 MPa, which is recommended strength by international standards, and offer the opportunity to produce sustainable building materials locally.

A Developed Constitutive Model for Sand and Clay under Monotonic and Cyclic Loadings

In this paper, a constitutive model is presented to model the behavior of various soils (sand and clay) in different loading conditions and the minimum required parameters are obtained. Although some practical features (concepts) of the bounding surface framework and modified Cam-Clay have been employed in its formulations, the model is developed mainly based on the generalized plasticity framework. Moreover, some concepts such as dilatancy relation and loading history surface are redefined. Finally, the proposed constitutive model is evaluated using the experimental data related to two different sandy soils and three different clays under different loading conditions. Finally, it is concluded that the proposed constitutive model can easily be calibrated for various clayey and sandy soils. It can depict different behavioral aspects of these soils under different monotonic and cyclic loading conditions.

A Review of Advances in Peat Soil Stabilisation Technology: Exploring the Potential of Palm Oil Fuel Ash Geopolymer as a Soil Stabiliser Material

This study aims to highlight the latest developments in the field of peat soil stabilisation technology via chemical stabilisation. The review examines the use of traditional stabilisers such as OPC and various non-traditional stabiliser materials, i.e., Palm Oil Fuel Ash (POFA)-OPC blends, chemical solutions, and geopolymer materials, to enhance the Unconfined Compressive Strength (UCS) characteristics of peat soils based on the ASTM D 4609 requirements. OPC, POFA-OPC blends, and alkaline solutions mostly produced stabilised soil samples that fell short of the ASTM requirements. Existing studies on the use of waste-derived geopolymers to treat peat soils are limited, while the use of POFA geopolymer materials has mostly focused on the improvement of clayey and silty soils. The results of soil stabilisation with geopolymer were very encouraging, as the strength gains were in line with the ASTM soil strength requirements. As a result of this review, it can be concluded that POFA geopolymer is a viable soil stabiliser material with the addition of Ground Granulated Blast Furnace Slag, and that the use of POFA-GGBFS geopolymer to enhance the strength properties of peat soils should be investigated. Doi: 10.28991/CEJ-2023-09-08-017 Full Text: PDF

A study of geotechnical properties on high and intermediate - compressible clay stabilized with eco-sand

The most of the clayey soils are problematic for various construction tasks because their susceptibility to fluctuations in moisture content which can drive up construction expenses. Such soils can make it challenging to work for the construction projects. To solve this problem, we should change the clay's characteristics by blending the suitable admixture for producing the stabilized material. Eco-sand is one of such stabilizing admixture which is generated from a cement Industry as a by-product, produced an amount of 1100 tonnes per 20 hrs. In this study, the two different types of clayey soils are used such as high compressible clay (CH) and Intermediate compressible clay (CI). They were blended with varying amounts of eco-sand, such as 10%, 20%, 30%, 40%, and 50%, respectively. The optimum percentage of eco-sand is derived from conducting the various tests on engineering properties on clay mixes namely unconfined compression tests with different curing intervals, dispersion studies, durability studies and hydraulic properties. Based on the results of the aforementioned experimental tests, the optimal percentage of eco-sand is determined to be 40% for clay with a high compressibility and 20% for clay with an intermediate compressibility.

The Response of Sandy and Clayey Soils to Weak and Strong Seismic Motions

The Response of Sandy and Clayey Soils to Weak and Strong Seismic Motions

Estimating Unconfined Compression Strength of Fly Ash and Cement Stabilised Clayey Soil using Artificial intelligence Techniques

The study aims to develop proposed predictive formulas for determining the unconfined compression strength (UCS) of fly ash and cement stabilised clayey soil based on Multi-Gene Genetic Programming (MGGP) and Artificial Neural Network (ANN) techniques. Thirteen parameters, including the soil characteristics, the binder types, the binder contents, the curing period, the mixing method, and the fly ash characteristics, such as calcium oxide (CaO) content, CaO/SiO2 ratio, loss of ignition, were considered as the independent variables in the model. The results show that the selected optimal ANN and MGGP models can predict the target values with high correlation coefficients (R-value approximately 0.994 and 0.973, respectively), and low errors. The performances of the MGGP and ANN models were compared based on statistical parameters and several external criteria. The study finds that both models show their generalisation capabilities with robust, powerful, and accurate prediction ability; however, the ANN model slightly outperforms the MGGP model. The proposed predictive equations formulated from the selected optimal MGGP and ANN models could help engineers and consultants to choose the suitable binder and a reasonable amount of fly ash in the pre-planning and pre-design period.

Remediation and mitigation measures to counteract orchard soil degradation by treated wastewater irrigation

Recent studies have shown that long-term irrigation with treated wastewater (TWW11Treated wastewater irrigation (TWW): Freshwater (FW): Blended TWW:FW in a 1:1 ratio (MIX): Low-frequency TWW-irrigation (LFI): TWW irrigated tuff trenches (TUF)) can lead to land degradation and reduction of crop performance in clayey soils due to additions of salts and organic compounds. This study investigated the effects of two remediation and two mitigation methods intended to alleviate the damage to soil properties following long-term irrigation with TWW. The experiment was conducted in a ‘Hass’ avocado orchard (Persea americana Mill.) grown on a clayey soil irrigated with TWW since 2009. The treatments implemented in 2016 included: TWW (control), freshwater (FW), blended TWW:FW in a 1:1 ratio (MIX), low-frequency TWW-irrigation (LFI), and TWW irrigated tuff trenches (TUF). The results showed that FW and MIX significantly reduced total salinity, salinity-related ions (Na and Cl), and sodium adsorption ratio (SAR) to (i) depths of 90 cm and 30 cm under drippers, respectively, and (ii) depths of 60 cm (except for chloride) and 30 cm between drippers, respectively, compared with TWW. TUF and LFI reduced soil salinity and sodicity under drippers but not between drippers compared with TWW. Moreover, FW significantly increased aggregate stability to a depth of 30 cm. TUF had the highest oxygen concentration in the root zone (35 cm depth), followed by FW. Considering the scarcity of freshwater, MIX and TUF are suggested as possible measures for reducing soil salinity and sodicity, and increasing aeration of clayey soils under long-term irrigation with TWW, respectively. Our findings contribute valuable insights into strategies for remediating and mitigating the detrimental effects of TWW irrigation on soil, thus promoting sustainable agriculture in regions facing water scarcity.

Cellulose‐Based Hydrogel as a Natural Medium for Paddy Seed Germination

AbstractCellulose hydrogel derived from cellulose fibers extracted from printed paper waste is prepared. The hydrogel derived from 3 wt% of the cellulose concentration exhibits a maximum water absorption capacity of 465.5%. The effects of the cellulose hydrogel on the soil moisture are evaluated using four types of soils namely river sand, clayey soil, loamy soil, and gley soil (the wetland soil). The potential application of cellulose‐based hydrogel as an eco‐friendly seed germination media of the paddy seeds under the soil‐less condition is evaluated. This study shows that paddy seeds exhibit a higher seed germination rate of 53% when cellulose hydrogel is used as a seed germination media as compared to seed germination rate ranging from 14% to 35% when various types of soil are used as the germination media. The prepared cellulose hydrogel could be applied as an eco‐friendly and cost‐effective seed germination media to enhance the paddy seeds' germination rate.

Investigating the effects of stabilization carried out using fly ash and polypropylene fiber on the properties of highway clay soils

Improving highway subgrades is the most crucial step that increases the performance and longtime durability of pavements. Using fly ash to improve the properties of subgrades and synthetic fibers as additives to increase their strength in recent years is an effective method. It is essential to determine how fly ashes affect the strength properties of subgrade soils in the long term with a time-dependent curing effect and how synthetic fibers affect the strength properties of subgrade soils, especially in the short term before curing. Furthermore, another vital issue is determining the extent to which freeze–thaw cycles that occur during winter months due to regional climatic conditions reduce the strength of the subgrade soils. For this purpose, a regional high-plasticity soil representing the problematic subgrade was reinforced with fly ash at different percentages (10%, 20%, 30% and 40%), and a series of experiments were carried out to determine the plasticity, compressibility and strength properties of these soil mixtures. Besides the clayey soil and fly ash, the microstructures of these mixtures were also examined by XRF, XRD spectrometry, FT-IR spectroscopy and SEM analyses and the relationships between mechanical behavior and microstructure were tried to be explained. Furthermore, the impact of polypropylene fibers added to the soil at 0.5% of the dry mass and freeze–thaw cycles on the strength of the subgrade soils was determined. The results showed that the effective fly ash mixture ratio for stabilization with fly ash was 10%, and when the 28-day unconfined compressive strengths of the fly ash mixture and the natural soil were compared, the fly ash mixture increased the strength by 85.8%. Furthermore, the fiber additives were determined to increase the shear strength at ratios ranging from 3.0% to 21.0% and that approximately 80% strength loss occurred in the natural soil due to freeze–thaw cycles, but fly ash and synthetic fiber additives can increase the strength by compensating for the strength loss caused by freeze–thaw cycles.

Different soil textures can interfere with phosphorus availability and acid phosphatase activity in soybean

To achieve sustainable agricultural activity, phosphatase determination is an important practice for improving the efficiency of phosphorus (P) management in tropical agriculture. The objective of this study was to evaluate acid phosphatase activity in different soil textures and P stress levels affecting the nutritional, chemical, biochemical, and agronomic aspects of soybean. Treatments resulted from factorial combination in a 3 × 3 factorial scheme, consisting of three soil textures (clay, medium, and sandy) and three P stress levels (severe, moderate, and control) with four replications. Three different soil textures were used in the research: Latossolo Vermelho Distrófico (LVd) with clay texture, collected in the native forest, equivalent Oxisol (Soil Taxonomy); Cambissolo Háplico Tb Distrófico (CXbd) with medium texture collected in the natural field equivalent Inceptisols (Soil Taxonomy); and Latossolo Amarelo Distrófico (LAd) with sandy texture collected in the natural field equivalent Oxisol (Soil Taxonomy). Soil electrical conductivity, P available (method Mehlich-1), and acid phosphatase activity (ρ-nitrophenol released) (μg h−1 g−1 soil) were analyzed and the samples were collected at a depth of 0–20 cm. Also evaluated were the height of plants, number of leave and branches, dry mass (root, leave, and stem), P total concentration in leaf, and P translocation (transport from root to shoot) of soybean plants 45 days after sowing. Results showed the clayey textured soil provided the best results for plant growth, root, stem, and leaf dry matter content, P total concentration of P in leaf, P translocation (transport from root to shoot), P available in the soil, and higher acid phosphatase activity of under P stress. Results showed that the Latossolo Vermelho Distrófico (LVd) provided the best results in managing P in different soil textures. However, based on growth and development results, a reduction in phosphate fertilization (P stress moderate) may favor acid phosphatase activity. Acid phosphatase activity can be used as an option in the management of P soluble activity in different soil textures. However, in front of the complexity of soil–plant–P–environment interactions, further research needs to be conducted to investigate better these effects of the da acid phosphatase on different soil textures.

Quantification of freeze–thaw hysteresis of unfrozen water content and electrical resistivity from time lapse measurements in the active layer and permafrost

AbstractWe quantified seasonal, in‐situ variation in ground electrical resistivity, unfrozen water content, and ground temperature using daily and sub‐daily measurements in active layer and in permafrost on a high‐latitude monitoring site in West Greenland. The in‐situ unfrozen water content in a clayey soil undergoing phase change was 10% higher during freezing than during thawing at the same ground temperature, thus shifting the freezing curve parameterization seasonally. The freeze–thaw unfrozen water content hysteresis was a measurable part of the energy balance of the active layer and corresponds to 12.1% of the total yearly enthalpy change for our field site. We also observed and quantified hysteresis in the relationships between ground electrical resistivity and unfrozen water content, where the inverted resistivities during freezing in the temperature range from 0°C to approximately −4°C were up to one order of magnitude higher than during thawing at the same unfrozen water content. As a result, the petro‐physical models that uniquely derive soil unfrozen water content from bulk soil electrical resistivity measured from ground surface do not fully capture the complexity of the in‐situ processes. The hysteresis should therefore be considered in quantitative interpretation of ground resistivity changes in terms of ground temperature and ice content changes.

Consolidation behaviour of palm-oil-fuel-ash-based geopolymer treated soil

In recent times, geopolymers have gained attention as a soil stabilisation binder due to their ability to improve the engineering properties of soil while remaining eco-friendly. This study seeks to investigate the stabilisation of soft soil using palm-oil-fuel-ash (POFA)-based geopolymers. A geopolymer was created by combining POFA with an alkaline activator solution composed of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). The mechanical and microstructural behaviours of two clayey soil types (samples S1 and S2) stabilised with four doses of the POFA-based geopolymer (G10PA, G20PA, G30PA and G40PA) were studied by conducting one-dimensional consolidation, California bearing ratio (CBR) tests, field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The optimum dosage found was G40PA for both soil samples. The CBR value of S1-G40PA was 1.7 times that of S1, while that of S2-G40PA was nearly 1.5 times that of S2. The void ratio of S1 was significantly reduced from 0.70 (untreated sample) to 0.56 (S2-G40PA), whereas for S2, it was decreased from 1.43 (untreated sample) to 0.43 (S2-G40PA). The microstructural analysis (FESEM) revealed that changes in material composition correlate with the consolidation behaviour, with the geopolymer gel-binding effect enhancing the mechanical properties of stabilised soils.

Prediction of Smear Effect on the Bearing Capacity of Driven Piles

This paper deals with prediction the effect of soil remoulding (smear) on the ultimate bearing capacity of driven piles. The proposed method based on detecting the decrease in ultimate bearing capacity of the pile shaft (excluding the share of pile tip) after sliding downward. This was done via conducting an experimental study on three installed R.C piles in a sandy clayey silt soil. The piles were installed so that a gap space is left between its tip and the base of borehole. The piles were tested for ultimate bearing capacity according to ASTM D1143 in three stages. Between each two stages the pile was jacked inside the borehole until a sliding of about 200mm is achieved to simulate the soil remoulding due to actual pile driving. The results of the tests exhibited that the pile might loss 14% of its ultimate capacity when it is loaded immediately after installation. Also, it was concluded that the pile may regain of about 9% of its original capacity after 30days of its installation.