scholarly journals Swelling potential of volcanic residual soils in Sumatra (Indonesia) in relation to environmental issues

2020 ◽  
Vol 8 (4) ◽  
pp. 1-10
Author(s):  
Prahara Iqbal ◽  
Dicky Muslim ◽  
Zufialdi Zakaria ◽  
Haryadi Permana ◽  
Nugroho A. Satriyo ◽  
...  
Keyword(s):  
Soil Surface ◽  
Environmental Issues ◽  
Liquid Limit ◽  
Physical Characteristics ◽  
High Plasticity ◽  
Residual Soil ◽  
Vegetative Cover ◽  
Residual Soils ◽  
Swelling Potential ◽  
Clayey Silt

AbstractSwelling potential characterization of clay-silt soil is an essential issue in stabilization, settlement, consolidation, and land suitability studies. This article attempts to explain the swelling characteristics of soils around the area of West Lampung, Lampung Province, Sumatra, Indonesia, in relation to environmental issues. An investigation in relation to the soil swelling potential was carried out using 15 disturbed soil samples collectd in the study area. The methods used were analyses of clay mineral geochemistry, physical characteristics, and the free swell ratio. These results showed that the soil in the study area was Quaternary tropical volcanic residual soil. These soils were formed in a proximal volcanic hydrothermal alteration environment. The soils of the study area have characteristics of high plasticity, a reddish-brown colour, and are clayey silt grained (MH) (USCS). The soils had loose physical characteristics in dry conditions; however, these soils tends to be plastic and sticky in wet conditions. Evidence of groove erosion was found at the soil surface. Based on XRD analysis, kaolinite, halloysite, and montmorillonite were types of clay minerals found in the soil. The soil had a clay content of 11.05–78.9%, a liquid limit value > 50%, a plasticity index value of 16.7–36.9%, a shrinkage value of 14.24–36.89%, a soil activity of 0.38–2.47; and an FSR value of 0.69–0.95. These characteristics have implications for swelling soil potential. The results showed that the soils in the study area had medium to very high swelling potential. These results suggest a risk of erosion in the area, which could cause soil degradation and a change in water quality. These soils are likely to affect land productivity and aquifer replenishment and will cause negative environmental and economic impacts. Thus, soil improvement techniques are needed. It is important to maintaining vegetative cover these soils and revegetation may be required.

scholarly journals Tropical Volcanic Residual Soil

2021 ◽  
Author(s):  
Prahara Iqbal ◽  
Dicky Muslim ◽  
Zufialdi Zakaria ◽  
Haryadi Permana ◽  
Arifan Jaya Syahbana ◽  
...  
Keyword(s):  
Research Area ◽  
Liquid Limit ◽  
Primary Forest ◽  
High Plasticity ◽  
Residual Soil ◽  
Residual Soils ◽  
Earth Construction ◽  
Red Color ◽  
Clayey Silt ◽  
Corrosion Of Steel

In West Lampung, Sumatra, Indonesia, tropical volcanic residual soils are formed from weathering of volcanic breccias in hydrothermal alteration areas with a thickness of up to 20 m. This soil has the characteristics of clayey silt, low to high plasticity, brownish-red color, has the potential to swelling, easily eroded, and slide when it is saturated, and contains the minerals kaolinite, halloysite, illite, dickite, nacrite, montmorillonite, despujolsite, hematite, and magnetite. The results showed that this soil can cause corrosion of steel and is widely used by the community as a medium for growing plants and vegetables and as a foundation for infrastructure (for example, houses). The volcanic residual soil of the research area had Low Rare Earth Element (LREE) potential and specific uses. The soil with characteristic low plasticity has Liquid Limit (LL) brine value <50% will be suitable for agriculture purposes, building foundations, and earth construction. At the same time, the other category is soil with intermediate to high plasticity characteristics, which has an Liquid Limit (LL) brine value >50%, was more ideal for the primary forest.

Geological and soil engineering properties of shallow landslides occurring in the Kutupalong Rohingya Camp in Cox’s Bazar, Bangladesh

Landslides ◽  
2022 ◽  
Author(s):  
A. S. M. Maksud Kamal ◽  
Farhad Hossain ◽  
Md. Zillur Rahman ◽  
Bayes Ahmed ◽  
Peter Sammonds
Keyword(s):  
Shear Strength ◽  
Bulk Density ◽  
Mineralogical Composition ◽  
Fine Sand ◽  
Liquid Limit ◽  
Engineering Properties ◽  
Anthropogenic Factors ◽  
Residual Soil ◽  
Geological Condition ◽  
Residual Soils

AbstractThe Forcibly Displaced Myanmar Nationals (FDMN), historically known as ‘Rohingya’ who fled the 2017 ethnic atrocities and genocide in the Northern Rakhine State of Myanmar, took shelter in Cox’s Bazar District of Bangladesh. The camp network, known as Kutupalong Rohingya Camp (KRC), is situated in the tectonically active tertiary hilly terrain. The KRC has been experiencing hydrometeorological hazards, where landslides are frequent. This study investigated the slopes’ geological condition, engineering properties and human interventions, which influence the landslides. The exposed slopes were relatively high (> 10 m) and steep ranging from 40° to 60° that have numerous polygonal tension cracks and fissures. From the geological and geotechnical aspects, there are three successive units of slope materials: (1) residual soils of sandy silt with clay, (2) highly weathered silty sandstones and (3) shale/clay with silt and fine sand intercalations at the bottom of the slopes. Field observations revealed that most slope failures occurred in the residual soil and weathered silty sandstone units. The residual soils have a bulk density of 1.49–1.97 g/cm3, a liquid limit of 25–48%, a plasticity index of 5–16% and an undrained shear strength of 23–46 kPa. The silty sandstones have a bulk density of 1.44–1.94 g/cm3, an internal friction angle of 34°–40° and a cohesion of 0.5–13 kPa. The mineralogical composition determined by the X-ray diffraction shows low clay mineral content, which does not affect landslides. However, the slope geometry, low shear strength with strain softening properties and torrential rainfall accompanied by anthropogenic factors cause numerous landslides every year. This study will help take proper mitigation and preparedness measures for slope protection in the KRC area and surroundings.

scholarly journals Adsorption of lead (Pb) in strongly weathered tropical soil (Ribeira Valley region - Brazil)

2019 ◽  
Vol 23 (4) ◽  
pp. 385-395
Author(s):  
Carla Patinha ◽  
Mariana Consiglio Kasemodel ◽  
Eduardo Anselmo Ferreira da Silva ◽  
Valéria Guimarães Rodrigues ◽  
Jéssica Pelinsom Marques
Keyword(s):  
Colloidal Particles ◽  
Chemical Properties ◽  
Liquid Limit ◽  
Tropical Soil ◽  
Residual Soil ◽  
Residual Soils ◽  
Initial Concentration ◽  
Local Soil ◽  
Physical And Chemical ◽  
The City

Lateritic soils have been widely used in the construction of landfill base liners for municipal and industrial waste. On the other hand, there is little practice in the use of strongly weathered residual soils for this finality. The use of local soil for the construction of liners in order to waterproof and retain contaminants represents an alternative to control this type of contamination. Thus, the objective of this study was to determine the physical and chemical properties of a strongly weathered tropical soil (residual soil) collected in the city of Eldorado Paulista (Ribeira Valley), and to evaluate the abilityof this soil to adsorb lead (Pb). The contamination of soil and water by Pb due to inadequate mining waste disposal is common in this region. The Pb was adsorbed by the residual soil, mainly at the lowest initial concentrations. When the initial concentration of 20 mg L-1 was used, the adsorption percentage of Pb was 92.5% and when the initial concentration was 100 mg L-1, the adsorption rate was 81.7%. In addition to the retention of Pb, this soil presented the following characteristics which are favorable for using soils in the construction of liners: fine granulometry, liquid limit (LL) of 57%, plasticity index (PI) of 33%, oxidizing medium and the predominance of negative charges on the surface of the colloidal particles. Thus, it is concluded that the weathered tropical residual soil exhibits characteristics that allow it to be used as a liner in the disposal of residues containing Pb.

Residual Large Trees Influence Short-term Succession Following a Volcanic Eruption in a Valdivian Temperate Rainforest

2021 ◽  
Author(s):  
Lisa Hintz ◽  
Dylan Fischer ◽  
Nina Ferrari ◽  
Charlie M.S. Crisafulli
Keyword(s):  
Soil Surface ◽  
Bare Soil ◽  
Understory Vegetation ◽  
Percent Cover ◽  
Vegetative Cover ◽  
Vegetation Response ◽  
Temperate Rainforest ◽  
Large Trees ◽  
Close Proximity ◽  
Disturbed Forest

Abstract Airborne volcanic ejecta (tephra) can strongly influence forest ecosystems through initial disturbance processes and subsequent ecological response. Within a tephra-disturbed forest, large trees may promote plant growth and create favorable sites for colonization. Three primary ways trees can influence post-eruption vegetation response include: 1) amelioration of volcanic substrates, 2) as source propagules from the tree or from associated epiphytes, and 3) by sheltering understory vegetation, thereby increasing rate of recovery near tree bases. Here, we evaluate Valdivian temperate rainforest understory vegetation response and soil characteristics in close proximity to large trees that survived the 2015 eruption of Calbuco Volcano. Understory vegetative cover was higher near the base of trees for mosses, many epiphytes, and some herbaceous, shrub, and trees species. However, significant interactions with year of measurement, and individualistic responses by many species made generalizations more difficult. Small shrubs and trees in particular demonstrated patterns of recovery that were frequently independent of distance. In some cases, percent cover of colonizing vegetation actually increased far from trees by 2019. The soil surface was similarly variable where bare soil cover was associated with locations proximal to tree bases, but material shed from living and dead standing vegetation increased wood and litter abundances on the soil surface away from the base of trees. Soils near trees had lower pH, elevated organic matter, and higher nitrogen and carbon. Our results support the assertion that in this temperate rainforest ecosystem, large trees can modify edaphic conditions and provide important early refugia for vegetative regrowth following a tephra fall event. Nevertheless, complex interactions through time with species and growth form, suggest the influence of large trees on plant establishment and growth with close proximity tree boles is more complex than a simple facilitative model might suggest.

Macrostructural and Microstructural Properties of Residual Soils as Engineered Landfill Liner Materials

2021 ◽  
Author(s):  
Lee Li Yong ◽  
Vivi Anggraini ◽  
Mavinakere Eshwaraiah Raghunandan ◽  
Mohd. Raihan Taha
Keyword(s):  
Tap Water ◽  
Chemical Precipitation ◽  
Soil Samples ◽  
Residual Soil ◽  
Diffuse Double Layer ◽  
Microstructural Properties ◽  
Residual Soils ◽  
Soil Leachate ◽  
Landfill Liner ◽  
X Ray

ABSTRACT This study assessed the performance of residual soils with regard to their macrostructural and microstructural properties and compatibility with leachate in pursuit of exploring alternative cost-effective and efficient landfill liner materials. A series of laboratory investigations was conducted on three residual soil samples by using tap water and leachate as permeation fluid to achieve the objectives of the study. The zeta potential measurements revealed that the presence of multivalent cations in the leachate decreased the diffuse double layer (DDL) thickness around the soil particles. The reduced DDL thickness caused a decrease in Atterberg limits of soil-leachate samples and changes in the classification of fine fractions. Additionally, the effects of pore clogging attributed to chemical precipitation and bioclogging were responsible for the reduction in measured hydraulic conductivities of soil-leachate samples. These effects can be clearly observed from the field-emission scanning electron microscopy images of soil-leachate samples with the appearance of less visible voids that led to a more compact and dense structure. The formation of new non-clay minerals and associated changes in the Al and Si ratio as reflected in the x-ray diffraction diffractograms and energy-dispersive x-ray analyses, respectively, were attributed to the effects of chemical precipitation. This study concluded that S1 and S2 residual soil samples are potential landfill liner materials because they possess adequate grading characteristics, adequate unconfined compressive strength, low hydraulic conductivity, and good compatibility with leachate. In contrast, the S3 sample requires further treatment to enhance its properties in order to comply with the requirements of landfill liner materials.

Small strain stiffness for granite residual soil: effect of stress ratio

2021 ◽  
Author(s):  
Xianwei Zhang ◽  
Xinyu Liu ◽  
Lingwei Kong ◽  
Gang Wang ◽  
Cheng Chen
Keyword(s):  
Stress Ratio ◽  
Small Strain ◽  
Residual Soil ◽  
Resonant Column ◽  
Residual Soils ◽  
Column Tests ◽  
Small Strain Stiffness ◽  
Deviator Stress ◽  
Granite Residual Soil ◽  
Stress Ratios

Most previous studies have focused on the small strain stiffness of sedimentary soil while little attention has been given to residual soils with different properties. Most studies also neglected the effects of the deviator stress, which is extensively involved in civil engineering. This note considers the effects of the deviator stress on the small-strain stiffness of natural granite residual soil (GRS) as established from resonant column tests performed under various stress ratios. Although increasing the stress ratio results in a greater maximum shear modulus for both natural and remolded residual soils, remolded soil is more sensitive to changes in the stress ratio, which highlights the effects of soil cementation. The data herein offers new insights to understand the stiffness of residual soil and other weathered geomaterials.

scholarly journals Effects of High Plasticity and Expansive Clay Stabilization with Lime on UCS Testing in Several Conditions

2021 ◽  
Vol 1000 (1000) ◽  
Author(s):  
Soewignjo Agus Nugroho ◽  
Gunawan Wibisono ◽  
Andarsin Ongko ◽  
Avrilly Zesthree Mauliza
Keyword(s):  
Soil Stabilization ◽  
Soft Soil ◽  
Fine Powder ◽  
High Water ◽  
Liquid Limit ◽  
Clay Soils ◽  
High Water Content ◽  
High Plasticity ◽  
Expansive Clay ◽  
Limit Value

Clay is a cohesive and very soft soil if it has high water content. To overcome this problem, clay soils with high plasticity need to be stabilized. The method of soil stabilization with lime is an alternative effort to improve soil that does not meet the standards. Lime reacts with groundwater so that it changes the property of the soil, reducing the stickiness and softness of the soil. Lime also functions to solidify (stabilize) and stabilize (stabilize) soil in the form of fine powder consisting of metals and inorganic mineral composition. This study aims to determine the effect of clay soils when carried out stabilization by using a limestone additive which varies in levels of mixture. The results showed that lime effective for the stabilization high plasticity and expansive clay by increasing the compressive strength value of UCS with lime content of 10% under curing conditions in 28 days and unsoaked by 319%, the liquid limit value reduced by 6% and the plastic limit value increased by 46%.

scholarly journals Geotechnical and Mineralogical Appraisal of Shale and Claystone Facies of the Maastrichtian Patti Formation, Bida Basin, Nigeria

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Olusola J Ojo ◽  
Oladele A Omotoso ◽  
Adams Agbelekale ◽  
Suraju A Adepoju ◽  
Ayodeji Awe ◽  
...  
Keyword(s):  
Particle Size ◽  
Civil Engineering ◽  
Construction Material ◽  
Liquid Limit ◽  
Geotechnical Properties ◽  
Atterberg Limits ◽  
Minor Amount ◽  
Low Permeability ◽  
High Plasticity ◽  
Swell Potential

The need for construction materials in the rapidly developing areas around Federal Capital Territory, Abuja, Nigeria cannot be overemphasized and this study was undertaken in line with this need. The study area, located about 60km from Abuja, is underlain predominantly by shales and claystones of the Patti Formation. These argillaceous rocks may offer locally sourced construction material if they meet certain specifications, however to date, there has not been a geotechnical study of these rocks. The geotechnical properties and the mineralogy of the shale and claystone were investigated to evaluate their suitability for civil engineering works. Particle size distribution, Atterberg  limits and X-ray diffraction analyses were performed on fifteen shale and claystone samples collected  from  three localities (along an approximately 25km transect) for determination of their geotechnical properties and mineralogical composition. Mineralogical data obtained show the samples are dominated by kaolinite with minor amount of montmorillonite. Quartz and minor amounts of microcline, rutile and anatase dominate the non-clay mineral fraction. Particle size data indicate high proportion of fines and they are well graded. The Atterberg limits indicate that the samples have average values of liquid limit of 51%, plastic limit of 23%, plasticity index of 29% and shrinkage limit of 13%. These indicate they are of medium compressibility, low to medium shrink/swell potential, marginal expansive rating and low permeability. High bulk specific gravity (average of 2.61) suggests the samples are inorganic and this is supported by the consistency limits values. Generally, the results indicate the shale and claystone can be useful as stabilizing materials in civil engineering works. In addition, the marginally expansive nature of the shale and claystone, low permeability and intermediate to high plasticity may make them suitable as road subgrade.Keywords— activity, Bida Basin, Gerinya, Kaolinite, plasticity, Patti Formation

scholarly journals Influence of the structure on the collapse potential and shear strength of a residual soil in the semiarid region of Northeast Brazil

2021 ◽  
Vol 337 ◽  
pp. 01003
Author(s):  
Valteson da Silva Santos ◽  
Allan B.Silva de Medeiros ◽  
Romário S.Amaro da Silva ◽  
Olava F. Santos ◽  
Osvaldo de Freitas Neto ◽  
...  
Keyword(s):  
Shear Strength ◽  
Expansive Soils ◽  
Friction Angle ◽  
Semiarid Region ◽  
Original Structure ◽  
Residual Soil ◽  
Residual Soils ◽  
Strength Parameters ◽  
Effective Measure ◽  
Two Samples

In the last decades, several engineering works have been developed in the Northeast of Brazil, a region marked by the occurrence of collapsible and expansive soils. This work aimed to characterize and study the behavior of two samples of residual soils collected in the municipality of Salgueiro-PE regarding their collapse potentials and shear strength parameters, in natural and disturbed conditions, evaluating the influence of the applied vertical stresses and the structural arrangement in these properties. The results obtained showed that the two samples analyzed show collapsible behavior, however, the observed potential for collapse was lower after the original structure arrangement was undone. From the direct shear strength tests, the strength parameters of the two soils were obtained, which pointed effective friction angle close to 30° and cohesive intercept close to 0 kPa. The destructuring of the samples did not cause a considerable variation in these parameters. Thus, it was possible to conclude that for these samples the microstructure has a predominant influence on the occurrence of collapsibility, but does not have the same relevance on the shear strength, such that the material’s destructuring can be considered as an effective measure to reduce the potential collapse.

Stabilization of clayey subgrade with waste pumice for road infrastructure

2015 ◽  
Vol 22 (5) ◽  
Author(s):  
Ömür Çimen ◽  
Mehmet Saltan ◽  
S. Nilay Keskin
Keyword(s):  
Mechanical Properties ◽  
Road Construction ◽  
High Plasticity ◽  
Test Results ◽  
Index Properties ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Swelling Potential ◽  
Project Costs ◽  
High Plasticity Clay

AbstractHigh-plasticity clayey subgrade, which is unsuitable for road construction, may sometimes occur along highway routes. In such cases, engineers need to change the route of a highway project, resulting in an increase in road length and project costs. In this study, waste pumice was examined for stabilization of high-plasticity clayey subgrade, which is inappropriate for road construction. For this purpose, the physical and index properties of clay and pumice were determined. Then, the pumice was mixed with high plasticity clay at different ratios by weight. By performing standard Proctor compaction tests on the mixtures, the effects of adding pumice on compaction were also studied. Unconfined compression tests and California bearing ratio (CBR) tests were performed on all pumice-clay mixtures, and the test results and the CBR ratios were compared for each sample, respectively. The results showed that pumice stabilization improved the mechanical properties and reduced the swelling potential of high plasticity clayey subgrade.

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