Unified Soil Classification System Research Articles

Swelling Potential and Mineralogy of Al-Hartha City Soil in Basrah-Southern Iraq

     Mineralogical and geotechnical properties used to analyse the swelling potentials of Al-Hartha City. According to mineralogy, montmorillonite is a dominated clay mineral (33.61%) followed by montmorillonite-chlorite (33.34%), kaolinite (9.18%) and illite (5.38%). While calcite, Quartz, Feldspar, and dolomite are non-clay minerals that are also present. According to geotechnical analysis, the percent of clay range between 9-42% with an average of 25.5%, silt 55-80% with an average of 67.5% and sand 0-17% with an average of 8.5%. While liquid limits and plasticity index are, respectively, 10–25% with an average of 17.5% and 35%–51% with an average of 43%. According to the unified soil classification system (USCS), these soils are mainly low plasticity lean clay soils (CL) and 10% classified as medium stiff elastic silt (MH). According to activity values, soils are primarily inactive-(70%), normally active-(20%), active-(10%), and their consistency is plastic. according to an assessment of soil expansivity based on index properties and activity, a significant amount of the soil is expansive. Additionally, there is an agreement between the results of the mineralogical tests performed on these soils and the results of the measures of soil expansivity obtained from the evaluation of the swelling of the soil based on assessments of its index properties.

Use of steel slag to improve the mechanical properties of subgrades in clayey soils

Large quantities of steel slag are generated annually throughout the world. Some slag from steel manufacturing is reused in the generation of other materials, such as hot mix asphalt aggregate, pipe filling, concrete, among others. The research aims to enrich the mechanical characteristics of soils and minimize road construction costs. The objective of this research is to find a material that increases the mechanical properties of the subgrade in clay soils with different plasticity indices using Electric Arc Furnace Slag (EAF) in percentages: 5%, 15% and 25% of the weight of the soil. From the tests carried out on the soil samples using parameters, it was possible to classify them by the Unified Soil Classification System (USCS) and also by the American Association of Highway Transportation (AASHTO) as low and high clays. plasticity. When testing the samples in their natural state and the samples with EAF, results were obtained that showed an improvement in the physical and mechanical properties of the clay soils with the addition of EAF, increasing the values of the Bearing Capacity Ratio (CBR) and the maximum dry density. of the clay soil as the percentage of HAE in the mixture increased. The optimal HAE addition content corresponds to 25% of the weight of the soil.

SOIL CHARACTERIZATION: INTEGRATING IN-SITU TEST, LABORATORY ANALYSIS, AND TERRAIN PARAMETERS

This research introduces an innovative methodology for characterizing geotechnical parameters of soils, crucial for designing foundations for various structures. Rather than relying on general correlations from geotechnical books, the primary goal is to obtain specific characteristic values tailored to the study area. The methodology establishes correlations between in-situ tests and laboratory tests to determine soil parameters in the Valley of the Chillos. The Valley of the Chillos is a geographical region in the southeastern part of Quito, Ecuador. It falls within the administrative zone of Los Chillos in the Metropolitan District of Quito. The valley is surrounded by the inactive Ilaló volcano to the north and the Pasochoa, Antisana, and Lomas de Puengasí mountains to the south, east, and west, respectively. To achieve the research objective, soil samples were collected using the Standard Penetration Test (SPT) at depths ranging from 1 to 15 meters, following the ASTM D-1586 standard. Additionally, undisturbed soil samples from the thin-walled Shelby tube were obtained in the field and subsequently tested in the laboratory. These tests covered aspects such as natural moisture content, granulometric analysis, Unified Soil Classification System, classification, liquid limit, plasticity index, specific gravity, void ratio, and degree of saturation. The results from both field and laboratory tests will be used to calculate the load capacity of foundations specifically for characteristic soils in the Los Chillos Valley, considering their classifications.

Effect of Crude Oil Contamination on Compaction and Consistency of Some Clay Soils from Parts of Yenagoa, Bayelsa State, Nigeria

Bayelsa state is the southernmost part of the crude oil prolific Niger Delta region of Nigeria where oil exploration and exploitation activities have resulted to the pollution of its land, water, and air. Most parts of the area have experienced crude oil contamination of one form or the other, and the effects on man and the ecosystem are wide ranging. This study has examined the effect of oil contamination on the compaction behaviour of two clay samples obtained at shallow foundation depths in Yenagoa. The two clay samples, A and B are classified according to the unified soil classification system (USCS) as high plasticity inorganic sandy fat clay, and sandy lean clay, respectively. 4, 8, and 12 % crude oil by mass of dry soil were used to mix with the soil samples and left to cure in plastic bags for 48 hours before testing. In sample B, liquid limit (LL) was found to increase by about 9% for all proportions of crude oil while plastic limit (PL) was increased by 13%, 15%, and 27% for 4, 8, and 12 % oil content, respectively. These increase in LL and PL also brought about an increase in plasticity index except for 12% crude oil treatment. However, in all, a low plastic soil was changed to a slightly high plastic one as plotted on the Casagrande chart. The maximum dry density (MDD) of the two samples was also reduced by oil contamination with an increasing oil content exacerbating the reduction of MDD. It is therefore, recommended that care be taken during construction when dealing with clay soils within a potential crude oil contaminated region.

A Green Infrastructure SDGS Num 11: Approach Planning Design Model Reliability of Permeability and Concrete Quality Rural Roads P3MD Program in Wonogiri

Design planning permeability and quality of rural concrete road construction work in the Program Pembangunan dan Pemberdayaan Masyarakat Desa (P3MD) of the Ministry of Villages, Development of Disadvantaged Regions and Transmigration in Wonogiri, which is environmentally friendly in accordance with the sustainable development goals of SDGs Number.11 Villages "Sustainable Cities and Community", is the urgency of global action to reduce the impact of climate change and overcome challenges in developing a village road infrastructure model that is sustainable and leads to Green Infrastructure. Testing the permeability of village road construction materials using a rational classification method based on the Unified Soil Classification System, ASTM and International Nomenclature Darcy’s Law by calculating the input discharge of rainwater seeping into the soil through the pores of road construction using a rational method, testing the compressive strength of concrete roads using Rebound Hammer / Concrete Hammer Test method, SNI Standard 03-4430-1997. The results of the input volume of rainwater seeping into the ground through the pores (run off) of rural roads construction in Wonogiri one year is 724,866 m3. The average compressive strength of concrete roads from the hammer test results for concrete road test is 290 kg/cm2> K-225 kg/cm2, than the desired construction, namely; standard deviation; (S=1.75), coefficient of variation (Kv= 7.35%), indicating that the data taken has a sufficient level of accuracy, while the uniform data is quite representative of the road section studied.

INVESTIGATION OF CALIFORNIA BEARING RATIO VALUE OF BAMA RIDGE SOIL ADMIXED WITH METAKAOLIN

The study focused on assessing the impact of Metakaolin on the properties of Bama Ridge Soil in the Maiduguri region and its environs. Soil samples, collected using a disturbed sampling method from two distinct locations, were transported to the laboratory in polythene bags to prevent moisture loss. According to the American Association of States Highway and Transport Officials (AASHTO) and the Unified Soil Classification System (USCS), the soil was classified as A-3(0) and CL. The California Bearing Ratio (CBR) values ranged from 19.23% to 26.66% for soaked conditions and 25.01% to 32.46% for un-soaked conditions, indicating its suitability as sub-grade material. The study suggested that a 15% Metakaolin content would suffice for lightly trafficked roads. However, caution was advised against using the soil as sub-base material for roads with heavy traffic density, as CBR values slightly exceeded 30%. This implies that while the soil shows promise for specific construction applications, it may not be optimal for handling the substantial loads associated with high traffic volumes.

Geotechnical investigation of soil bearing capacity a case study of Nile university of Nigeria

Geotechnical investigation was conducted within Nile University soil with the aid of the master plan showing areas awaiting future developments. This is as a result of the university planning for infrastructural expansion due to such in student’s population. Each time a building construction is to be taken place, the university management spent another set of money on conducting geotechnical investigation. There are no comprehensive geotechnical information of the soil bearing capacity that can represent the whole of Nile university space/area of 1,153,208,008?2. In-situ and laboratory test were carried out. Three boring point were established using map at a regular interval and drilled to a depth where basement was encountered. In each test sample were collected at 1.5m interval. The standard penetration procedure consist of split spoon and u-tube as set forth in ASTM-1990. The test involves counting the number of blows required to drive a spoon sampler by 300mm, using a weight of 64kg hammer with a free fall of 76mm on the anvil of a rod arrangement. An initial penetration of 150mm is allowable on the sampler known as sitting blows before counting the subsequent blow for the required 300mm. another six trial pit were evenly spread at regular interval at different location within the university. It was manually excavated by hand, undisturbed and disturbed sample were extracted by hand auger and shovel. Sample were extracted at 1.5m depth, properly labelled and taken to laboratory. The laboratory test of the extracted soil sample include moisture content, grain size distribution, liquid limit, plastic limit, consolidated drained test and unified soil classification system was adopted. It was observed that the results obtained from Standard Penetration test indicates variance in allowable bearing capacity with depth, between 0.0-0.5m is 56??⁄?2, 0.6- 1.0m is 112??⁄?2, 1.5- 2.0m is 215??⁄?2, 3.0 – 3.5 is 279??⁄?2, 4.5 – 5.0m is 273??⁄?2. The soil type were predominantly medium dense to very dense inorganic silty sand with clay content less than 5%. Point of refusal was encounter at 6m depth, boring was then terminated. The Direct shear box test analyses obtained from site BC and CH gave the allowable bearing capacity values of 250??⁄?2 at pit one, 211.2??⁄?2 at pit two, 798.1??⁄?2 at pit three, at pit four, 798.1??⁄?2, at pit five, 918??⁄?2 , at pit six 960.5??⁄?2, but with the results obtained from oedometer test show that we cannot adopt this allowable bearing capacity value due to it high settlement rate beyond the acceptable settlement rate set by Development Control in Nigeria, which is 100mm. therefore based on the result from oedometer test the allowable bearing capacity of 120??⁄?2 was adopted with a safe consolidated settlement of 52mm at site BC. While an allowable bearing capacity of 100??⁄?2 with safe consolidated settlement of 55mm was adopted for site CH. Site BC is predominantly underlain by Sandy Silt. While site CH the predominant soil type was Clayey Sand. Pad footing at 1.5m depth and 210??⁄?2 allowable bearing capacity should be adopted. It is recommended that for both site BC and CH pad foundation at 1.5m having maximum individual column load less than 600??⁄?2 with a ground beam adopted.

Hydraulic characteristics of gypseous sand soil using modeled oedometer cell

The current study investigates the permeability of the sand soil using a modified Odometer cell with a constant head connected to a data logger and computer software. The soil sample is taken from the Al-Jameah district in Al-Najaf city, Iraq. The soil is classified as “SP” according to the unified soil classification system, with a gypsum content of 29%. A modified Oedometer with computerized water volume change is adopted. The samples are disturbed and remolded into the Odometer cell with different densities of 90% and 95% of the maximum Proctor dry density and initially dry. Each of the specific density samples is subjected to three different water heads: 80, 100, and 120 cm. The first head (80cm) is applied to the initially dry soil up to a saturated and steady state. While the other heads are subjected after the completion of the first one. The results of the modification are verified with the results in the literature and it is more flexible and accurate due to the digital recording of the data by the Linear Variable Differential Transformer (LVDT). The results of the water volume change versus time and the coefficient of permeability state that the dry condition (first head) of the specimen is the longest duration of the test for both 90% and 95% density in the change from dry to saturated and then to steady condition. For a 95% density longer than the 90% as expected, but after completing the saturation by the first head, there are method results of the 90% and 95% density, and this may be attributed to the higher water head and/or the effect of the gypsum dissolution.

Study of Sediment Deposit Characteristics based on Geotechnical Properties and Geographic Information System (GIS) Approaches

Several sedimentation processes occur in the downstream area between river mouths and the sea. One of the effects of this sedimentation process is the occurrence of siltation around the coast. Not infrequently, this disrupts sea passages when the ship is about to head to the pier or go to sea. Kuala Beach is one of the locations in Pangkalpinang where the sedimentation process continues to occur enough to disrupt the smooth flow of sea traffic. This study aims to provide an overview and analysis of results related to sediment characteristics, spatial analysis of deposits, and predictions of deposition rates around Kuala Beach, Pangkalpinang City. This research was conducted using the following methods: 1) Method of investigating sediment characteristics by collecting data through field testing in the form of hand drills and laboratory testing, 2) Spatial analysis method by mapping the area of sedimentation based on the results of sediment characteristic tests using Agisoft Metashape and QGIS. The results of this study note that sediment deposits are dominated by sediments with sandy grain characteristics (SP symbol based on the Unified Soil Classification System) and a fine grain content (passing sieve number 200) of around 1-3%. The pattern of distribution of sediment deposits is known to have relatively flat contours and relatively uniform characteristics down to a depth of 1.5 m. The coefficient of grain uniformity (Cu) is in the range of 2.43-8.2 with the tendency of uniformity level getting higher to the southeast. The coefficient of grain gradation (Cc) is in the range of 0.44-1.64 with the tendency of the gradation level getting better to the southeast.

Diffuse reflectance spectroscopy and digital soil mapping for assessing soil-associated off-road vehicle mobility risk

Soil attributes such as granulometric fractions and Atterberg limits (LL: liquid limit, PL: plastic limit, and PI: plasticity index) are needed to assess off-road vehicle mobility (OVM) risks. Parameters describing these attributes are generally measured in soil samples collected from a few locations through cumbersome laboratory methods. Although diffuse reflectance spectroscopy (DRS) can rapidly yield estimates for soil attributes in samples collected from specific locations and digital soil mapping (DSM) can transform such discrete measurements into spatially-continuous inference systems, these two technologies are rarely used for assessing OVM risks. In this study, we combined the DRS and DSM approaches for deriving spatially-continuous estimates for the key vehicle mobility parameters (gravel, sand, and fine particles; Cu: coefficients of uniformity; Cc: coefficient of curvature; LL; and PI) and classified soils using the Unified Soil Classification System (USCS). A total of 204 soil samples were collected from the north-eastern Himalayan state of Sikkim for measuring these parameters along with spectral reflectance over the visible and near-infrared region. Results of the chemometric models in the DRS approach showed that the USCS parameters may be estimated with the coefficient of determination (R2) values as high as 0.72. The fine (<2 mm diameter) fraction spectra provided the best estimates for the Atterberg limits while a combination of spectra collected from fine and coarse (>2 mm diameter) fractions was effective in estimating other granulometric fractions except for sand, which was best estimated using the coarse fraction spectra. With the DSM approach allowing effective mapping of these parameters, a spatially-continuous framework to quantify soil-associated OVM risks was developed for Sikkim for the first time.

Employing Data Mining Techniques for Engineering Soil Classification: A Unified Soil Classification System Approach

Employing Data Mining Techniques for Engineering Soil Classification: A Unified Soil Classification System Approach

Properties of dredged material and potential scope of its beneficial use: A case study of the Pussur River in Bangladesh

The Pussur River, an important river in Bangladesh, requires approximately 6 × 106 m3 of sediment to be dredged per year. At present, this dredged material is mainly dumped on the nearby agricultural and fish-cultivation lands, causing a reduction in productive land and producing negative impacts on people's livelihoods. This study aimed to investigate the engineering and environmental properties of the dredged sand of the Pussur River and evaluate the viability of its potential uses in different sectors. Bed sediments from the Pussur River and dredged material from disposal sites were collected, and laboratory investigations were performed. The test results showed that the dredged material of the Pussur River mainly consisted of fine sand with a fineness modulus ranging from 0.58 to 0.72 and could be classified as poorly graded sand according to the Unified Soil Classification System. This sand was also found suitable for land development, with a fair to poor suitability rating. Given the low concentration of heavy metals (at uncontaminated/slightly contaminated levels), the dredged sand might be safely used for land reclamation, landfill cover, and horticultural purposes, or else for other geotechnical applications without further treatment. After washing/leaching, the dredged sand could also be used as a partial replacement for local sand in concrete works. Moreover, there is a possibility of exporting the dredged sand to Singapore and the Maldives as filling material. These findings will help policymakers design dredging projects with a proper spoil management plan accounting for the dredged material's beneficial use.

Effect of Composite Portland Cement for Subgrade Stabilization and the Effect on Unsoaked CBR Value

Soil is a material that has an essential role in construction. Soils that have low bearing capacity require soil improvement. One method of soil improvement is soil stabilization using composite portland cement. Based on the results of the Dynamic Cone Penetrometer (DCP) test, the location in this study, namely Cibingbin village, Pandeglang Regency, has a bearing capacity of 2.67%, meaning that the soil at this location needs to be repaired. This study aimed to determine the effect of portland cement on physical properties and unsoaked CBR values. Variations of portland cement used were 0%, 4%, 6%, and 8%, with curing times of 0 days and seven days. The results showed that based on the unified soil classification system (USCS), the soil classification was in the CH category (inorganic clay with high plasticity, fat clay) and the maximum CBR value was obtained at 8% Portland cement variety at seven days curing time, namely 13.23%.

Field tests for the identification of silts

Accurately identifying soil texture and understanding soil behaviour in terms of plasticity is a crucial initial step in properly characterizing a site, which in turn facilitates appropriate sampling and scheduling of laboratory tests. Soil identification techniques in literature are effective at assessing pure clays and silt–clay mixtures. This paper presents a comparative study between field tests, soil plasticity classifications, Atterberg limits, mineralogical and chemical data, SEM imagery, and stereographical microscopy. Natural residual soils comprising varying quantities of clays, silts, and sands were used and subjected to the same field and laboratory protocols. The findings of this study demonstrate that a series of field tests can effectively characterize and classify soils ranging from coarse soils to fine soils exhibiting non- to highly plastic indices with particle sizes less than 2.00 mm. By employing a single list of field tests that only necessitate water and commonly available stationery materials on-site, the researchers have presented a valuable tool for on-site determination of soil texture and inference of the Unified Soil Classification System (USCS). This approach streamlines the process and provides professionals with an efficient means of assessing soil properties and determining problem soils at an early stage of the investigation and during construction of high fills.

A novel finer soil strength mapping framework based on machine learning and remote sensing images

Soil strength is an important factor for assessing the vehicle trafficability in the wilds and making reliable off-road path planning. Rating Cone index (RCI) has been widely used as an indicator of soil strength for mobility assessment. Currently, regional RCI are mainly obtained by using Soil Moisture Strength Prediction (SMSP) Model based on the Unified Soil Classification System (USCS) soil types and soil moisture at critical depth. However, USCS classification is inaccessible directly in most soil databases. And current soil moisture products are of coarse spatial resolution and only reliable in soil surface layer. It is costly to arrange ground survey for USCS soil type and the fine soil moisture in deeper layers cannot be obtained directly. To fill this gap, a novel framework is proposed to generate finer RCI-based soil strength map. To gain USCS soil classification in an un-surveyed study site, RF, GBDT, XGBoost and LCE ensemble learning models were trained with data from gSSURGO Database which contains USCS soil types and soil properties, and then make prediction on data from SoilGrids Database by using same properties. Then, to obtain the finer soil moisture of critical depth, these tree-based models were constructed with ground observation data, Sentinel-2 images, topographical data and soil properties with higher spatial resolution. The SMSP model is finally used to generate the finer daily soil strength map for the study site. The proposed framework highly improved the resolution and reliability of existing soil strength map generating methods, and can provide detailed soil strength information.

Coupld thermo-hydraulic modelling of heat storage in an embankment

Under temperate climates, the storage of excess heat collected in summer to compensate for insufficient heat supply during winter corresponds to the concept of long-term heat storage [1]. Fisch et al. [2] analyzed the cost-performance ratios of twenty-seven existing or planned large-scale storage systems in Europe. Their results showed that the seasonal storage model could meet 50-70% of the annual heat demand, while the diurnal model could meet only 10-20%. The storage of thermal energy is possible in different modalities among which heat storage in the form of sensible heat consists of raising the temperature of a material without changing its initial state [3]. Giordano et al. [4] estimated that a volume of 34 m3 of water could store 10 GJ of sensible heat, whereas 43 m3 of saturated soil or 62 m3 of unsaturated soil (S= 50%) would be required to store the same amount of energy.&#x0D; To store sensible heat in the ground, heat exchanger loops could be buried in the soil [5]. In an embankment, heat exchanger tubes could be installed during construction with no additional drilling or excavation [6]. This is a major advantage making geothermally-equipped embankments quite promising as eco-friendly devices for energy storage. However seasonal energy storage/retrieval from earth structures arises many challenges with respect to: (i) controlling heat loss during the intermediate periods (spring/autumn) [7]; (ii) managing the moisture transfer within the structure to ensure energetic efficiency and mechanical stability; (iii) evaluating the impact of cyclic temperature variations on the thermo-hydro-mechanical properties (THM) of the soil. Therefore, a coupled thermo-hydro-mechanical model would be necessary to correctly predict the long-term behaviour of these systems and ensure their sustainability.&#x0D; In this study, the possibility of heat storage in backfill structures was investigated from a geotechnical point of view. It is worth mentioning that neither the technical aspects of heat pump design, nor the economic efficiency of the system will be addressed. The thermal efficiency of horizontal heat exchangers in an embankment was numerically investigated using coupled finite element analysis. The thermo-hydro-mechanical properties of the compacted soil, typically used for building embankments, were first investigated through laboratory testing. The tested soil was sampled near Paris, France [8], with an optimum water content of 16% and a maximum dry density of 1.81 Mg.m-3. This material was classified as sandy lean clay, CL, according to the Unified Soil Classification System [9]. &#x0D; The finite element software Code_Bright was used to investigate first the TH behaviour of an embankment, equipped with heat exchangers, during energy storage/retrieval phases through thermo-hydraulic numerical simulations. The analysis considered the heat conduction as well as the vapour and liquid water transfer mechanisms in the unsaturated porous medium. The van Genuchten Model for the water retention curve and a power law was selected for the unsaturated hydraulic conductivity. The parameters of these hydraulic constitutive models were fitted from laboratory tests except the power parameter which was estimated based on [10]. The default procedure was used to handle the temperature-dependency of the thermal conductivity of the soil’s solid phase with parameters fitted on laboratory measurements while the thermal parameters of the water and air phases were assumed to be constant.&#x0D; The parallel horizontal heat exchangers composed of tubes of 0.06 m in diameter were modelled in a 10 m height embankment built on a subgrade soil supposed to have similar thermal and hydraulic properties (Figure 1). Based on the literature [3], at summer time the temperature in the heat exchangers (Texchangers) was imposed in the range from 25 to 50 °C during the injection phase, and to 5°C during the retrieval period in winter and was maintained constant during each season.&#x0D; Autumn and spring seasons were considered as relaxation periods during which no temperature variations were applied in the exchangers.  Various aspects were investigated such as the exchanger tubes locations and spacing, the heat injection-extraction scenarios, with and without insulation cap, and long-term behaviour over several years [8]. &#x0D; These simulations demonstrated the feasibility of seasonal heat storage in an embankment in temperate climates. Long-term simulations for a 10-year period showed that the heat loss during intermediate seasons tends to decrease reaching a plateau after 7 complete thermal cycles.&#x0D; For example, in one of the studied cases, 3 staggered rows of exchangers were modelled [Figure 1]. The horizontal distance between the exchangers was considered to be 3 m. To limit the temperature loss, an insulation sheet of 0.05 m thick with a low thermal conductivity of 0.03 W/m.K. [4]. The modelling results showed that the embankment core temperature initially at 12°C, increased evenly up to 34.4°C during summer and then decreased down to 14°C by the end of winter. &#x0D;  &#x0D; Currently the improvement of this approach is under process to consider more realistic climatic conditions (for both temperature and humidity) based on measured meteorological data. The effect of the continuity of the exchangers’ loop inducing temperature variations along the path will also be taken into account through a 3D calculation, and would enable the thermal efficiency of the storage to be assessed more accurately. Finally, the consideration of mechanical behaviour should provide an insight on how the stability of the embankment could be affected by the thermal cycles.

Sifat-sifat Fizikal, Kimia dan Morfologi Tanah Laterit di Daerah Bandar Baharu, Kedah

Bandar Baharu District in southern of Kedah, Malaysia is extremely rich in laterite soil. The district is distinguished by the widespread presence of laterite soil, making it critical to thoroughly explore its physical, chemical, and morphological properties. Understanding these properties is essential for determining the acceptability and behaviour of laterite soil in a variety of engineering and building applications. Thus, the objective of this study is to analyze and evaluate the physical, chemical, and morphological properties of the selected laterite soil. Three sources of laterite soils have been identified in Sungai Kechil, Bandar Baharu, and Relau. The samples are labeled as SS-A, SS-B, and SS-C. The soils are categorized as SM, SC and MH respectively according to classification by Unified Soil Classification System (USCS). Since the pH values were less than 6, all of the soils were acidic. The X-ray fluorescence (XRF) characterization shows that the three soil samples have three main chemical components, namely silicon dioxide (SiO&lt;sub&gt;2&lt;/sub&gt;), aluminium oxide (Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;) and iron oxide (Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;). According to the X-Ray diffraction analysis (XRD) results, the minerals discovered in the laterite soils were gibbsite, quartz, kaolinite, and magnetite. Based on the scanning electron microscope (SEM) image, the sample with the highest fine particle content, which is 55.7% for the SS-C sample, shows the smallest pore size.

COMPACTION CHARACTERISTICS AND WORKABILITY OF THE LATERITIC SOIL-IRON ORE TAILINGS IN PAVEMENT CONSTRUCTION

The mining waste deposit such as iron ore tailings (IOT) in Nigeria is a menace to the environment by constituting a nuisance to the mining industry, and its effect on lateritic soil as a compaction and plasticity reduction material for road pavement is considered in this study. The used natural lateritic soil was classified as A-7-6(11) or CL by the American Association of State Highway and Transportation Officials (AASHTO) and Unified Soil Classification System (USCS) respectively. Up to 16% of the soil’s dry weight was modified with iron ore tailings (IOT). Studying the effects of IOT on the altered soil focused on its cation exchange capacity, plasticity, compaction properties and California bearing ratio (CBR). British Standard Light (BSL) energy was used for the compaction process. However, the results of regression analysis showed that the optimum moisture content had a substantial impact on the soil CBR values. The results of the tests show that as the IOT content increased, plasticity and compaction characteristic values increased. Although an optimal 10% IOT treatment of lateritic soil significantly improved its strength properties, the plasticity characteristics recorded exceeded the requirement specified by the Nigerian General Specifications for direct use as a subbase or base material. Thus, reusing 10% iron ore tailings as filling materials required additional percentages of other pozzolanic materials to lessen the environmental problems associated with their deposition.

River bank erosion vulnerability demarcation based on the sensitivity analysis of geotechnical parameters: Majuli Island, India

The present study assesses the vulnerability of the river bank area most sensitive to erosion by combining the data obtained from existing literature and performing numerical simulation using finite element-based numerical code. Various geotechnical parameters, like average particle size (D50), Plasticity Index (PI), Elastic Modulus (E), Dry Unit Weight (γd) or Saturated Unit Weight (γsat), Coefficient of Permeability (k), Undrained Shear Strength (cu), Moisture Content (w%) and soil types based on the Unified Soil Classification System (USCS), were taken into account. Weighted Ranking Analysis (WRA) was performed based on the sensitivity of relevant geotechnical factors affecting bank erosion. The results indicate that the areas influenced by the Subansiri River (western bank) and the Brahmaputra River (southern bank) fall in the highly vulnerable zone category, while the Luhit and Kherkutia Suti Rivers (northern bank) fall in the moderately vulnerable category to river bank erosion.

Laboratory Testing and Analysis of Clay Soil Stabilization Using Waste Marble Powder

Soil stabilization is a critical step in numerous engineering projects, preventing soil erosion, increasing soil strength, and reducing the risk of subsidence. Due to its inexpensive cost and potential environmental benefits, waste materials, such as waste marble powder (WMP), have been used as additives for soil stabilization in recent years. This study investigates waste marble powder’s effects on unconfined compressive strength (UCS) and clayey soil’s ultrasonic pulse velocity (UPV) at different water contents and curing times, and artificial neural networks (ANNs) are also used to predict the UCS and UPV values based on three input variables (percentage of waste marble dust, curing time, and moisture content). Geo-engineering experiments (Atterberg limits, compaction characteristics, specific gravity, UCS, and UPV) and analytical methods (ANNs) are used. The study results indicate that the soil is high-plasticity clay (CH) using the Unified Soil Classification System (USCS), and adding waste marble powder (WMP) can significantly improve the UCS and UPV of clay soils, especially at optimal water content, curing times of 28 days, and 60% WMP. It is found that the ANN models accurately predict the UCS and UPV values with high correlation coefficients approaching 1. In addition, this study shows that the optimum water content and curing time for stabilized clay soils depend on the grade and amount of waste marble powder utilized. Overall, the study demonstrates the potential of waste marble dust as a soil stabilization additive and the usefulness of ANNs in predicting UCS and UPV values. This study’s results are relevant to engineers and researchers working on soil stabilization projects, such as foundations and backfills. They can contribute to the development of sustainable and cost-effective soil stabilization solutions.