Soil Classification

A database of 641 fall cone tests on 101 soil samples from twelve countries has been analysed to determine the best mathematical relationship linking undrained shear strength with liquidity index. From the database, it is shown that the use of a linear relationship linking liquidity index and the logarithm of undrained shear strength that uses the commonly assumed 100-fold factor increase in strength from liquid to plastic limit
over-predicts the measured data of soil strength. The use of a factor of about 35 for the ratio between the strength at liquid limit and that extrapolated to plastic limit is shown to be more realistic. Logarithmic liquidity index is examined and found to also correlate strongly with the logarithm of undrained shear strength, however it is shown that no great statistical improvement is present compared with the semilogarithmic
formulation. When considering data of individual soils a power law fitting is shown statistically to be the preferred mathematical function.

The climate is an important factor in the formation of soils and can be determinant in its characteristics. The aim of this study was to evaluate the influence of rainfall gradient on the formation process of Luvisols in the semiarid region, studying their morphological, physical and chemical attributes. Three soil profiles were described and collected under the following rainfall conditions: very dry < 400 mm, 400 > dry < 600 mm and sub-humid > 600 mm. The soils were analyzed for physical (particle size, clay dispersed in water, soil and particle density, degree of flocculation and porosity) and chemical properties (Ca2+, Mg2+, Na+ and K+, Al 3+, H+ + Al, COT, P and pH). It was noted the influence of rainfall in the pedogenetic processes that resulted in deeper soils the greater the rainfall in the region; the influence of precipitation on physical attributes was evidenced in clay contents; no clear influence of rainfall on fertility was noted. Thus, it was not possible to identify an isolated influence of rainfall levels on the chemical properties of soils. In general, the Luvissols in the very dry condition showed a higher content of nutrients available to the plants compared to other Luvisols.

This paper presents the Référentiel Pédologique (RP) and underlines some particular features of this reference base for soils. A large room is devoted below to its basic concepts and underlying philosophy. Are also emphasized the numerous similarities between the RP and the World Reference Base for soil resources (WRB). That is not surprising because both systems were elaborated during the same period on the basis of converging conceptions. Moreover, the authors of the RP insisted to give a rather wide freedom to users, having confidence in their ability to analysis and synthesis. The pros and the cons of this freedom are discussed. The reader will notice also to what extent this flexible system is conceived on modern design and breaks with old habits in this domain of soil classification and designation.

It is now widely recognized that local farmers possess an important body of knowledge concerning soils and their use for agriculture. This article argues that in order for that knowledge to be useful for sustainable development interventions, it is necessary to go beyond the collection of indigenous soil taxonomies and also explore the theories farmers have on soil formation and degradation processes. Based on field research in eastern Burkina Faso, the article demonstrates that farmers' theories of soil go beyond practical rules of thumb and include complex concepts about soil processes and fertility. In this sense they are similar to scientific theories of soil. It is argued that understanding the similarities and differences in soil related concepts, such as that of soil fertility, could do much more to improve communication between farmers, researchers and development workers than only comparing taxonomies. Furthermore, capturing the grammar (theories) rather than the sentences (taxonomies) provides a much clearer insight to how farmers will deal with changing circumstances and new crops than the static way in which local taxonomies are often treated. Finally, local soil theories are a better point of departure in terms of creating the necessary comprehension of farmer practices required for effective collaboration towards sustainable development.

Soils systematic arrangement into groups or categories on the basis of their characteristics has become imperative in view of the ever increasing need for the soil-with particular reference to sustainable landuse. Soils of Edo state Nigeria were characterized with a view to understanding its intricate properties and classify it using the United States department of agriculture (USDA) soil taxonomy and correlated with the world reference base (WRB). A free survey technique was used in identifying soil mapping units under different parent materials using the Edo state geological and mineral map. Pedons 1, 2 and 3 were marked as Ekpoma, Benin and Okpella soils respectively. Pedon 1 is derived from clayey sands, pedon 2 from sands and pedon 3 from shale and mudstones. Results showed that in all the three different parent materials sandy and loamy sands were the dominant textural classes. Pedon 3 was found to have more sand followed by pedon 2 and pedon 1, respectively. The C/N ratios in all the profile showed the trend similar to that of OC. Ca and Mg were found to range from very low to low in pedon 1 and 2 and moderate in pedon 3. The available phosphorus did not follow any regular pattern but decreased down the profiles. Total exchangeable acidity (TEA) was lowest in pedon 3(0.05 cmol/kg) and highest in pedon 1(1.12 cmol/kg).the effective cation exchange capacity (ECEC) of the soils were critically low, an indication that these soils requires amendment for crop production. The percentage base saturation has relatively high mean values 67.48, 55.50 and 97.68% for pedons 1, 2 and 3 respectively and the LDS showed significant difference among the three different parent materials. There were positive correlations between the soil pH and OC, CN, available phosphorus, TEB (Ca, Mg, K, Na). pedons 1 and 2 were classified as Alfisols (Isohyperthermic Psammentic Arennic Hapludalfs) while pedon 3 was classified as typic kandiustalfs. The landuse potential in Edo state under these different materials is high provided integrated soil fertility management practice is put in place.

Soil classification is an essential piece of geology. However, many examinations have assessed the precision and consistency of the soil classification using various techniques. This examination starts by evaluating the verifiable advancement of soil classification science. The verifiable audit contextualizes the wordings and the speculations of soil development factors, which supported soil classification frameworks. This paper is intended to review some research papers on soil classification and analyze the limitations of implemented techniques by their parameters. In the age of digital world, it is beneficial to obtain the information from image without any hassle. Machine learning is an approach through which we can obtain the better level of accuracy and minimize the false alarm rate. But machine learning requires so many samples through which we can observe the correct precision that also requires much storage that may takes much processing time that reduces the feasibility of the system. We have to train a system with limited number of samples with high iterations that produces higher precision rate with minimal errors.

This paper compares EuroCode 8 (EC8) and the Japanese seismic design code (BCJ) for steel moment frames and braced frames. Soil classification, magnitude and shape of unreduced elastic response spectra, distribution of seismic shear along the height, member ductility requirements, and behavior factor are compared. It was found that the two codes are relatively similar except for the seismic force

The Atterberg Limits are the most common tests specified by practicing geotechnical and pavement engineers the world over. They are used to classify soils using the framework pioneered by Terzaghi and Casagrande during their work with the US Public Roads Bureau in the 1920s and 1930s and are also correlated with many fundamental soil parameters, used in design and construction projects. In the 21 st century the Atterberg Limits remain a key component of the testing armory of practicing geotechnical engineers as they can be obtained easily for the large numbers of samples that are needed on major construction projects and allow for rapid assessments of key soil parameters. Their fundamental definitions are worthy of review; the thread-rolling test for plastic limit has remained largely unchanged since Atterberg first described it in 1911 but the definition and measurement of liquid limit varies across the globe. The fundamental mechanics of the Casagrande Cup liquid limit have been the subject of recent study showing clearly that liquid limit determined in this way relates to a fixed value of specific soil strength (i.e. strength per unit density) as opposed to a fixed strength value when liquid limit is measured by the fall-cone method. These findings explain the deviation between liquid limits measured by the two methods for high plasticity soils without the need to invoke different strength regimes. The brittle failure mechanism in the thread-rolling test has also been recently reexamined. It is proposed that the brittle failure observed in the plastic limit test is caused by either air entry or cavitation in the clay and plastic limit and does not correspond to a fixed strength. The Atterberg Limits are used to compute liquidity index which is widely related to clay strength variation, this is critical for many areas of construction (especially when rapid assessments of strength are required). The Russian code for the design of piled foundations, for example, uses liquidity index values to assess shaft friction. Recent research outcomes at the University of Cambridge have challenged certain assumptions pertaining to widely-used correlations between liquidity index and undrained strength.

The liquid limit is defined as the point at which a clay's behaviour changes from liquid to plastic. This transition is in reality gradual, rather than sudden. The definition of when this transition has been crossed must therefore be determined based on some arbitrary criterion. The percussion cup method of determining liquid limit in the manner suggested by Atterberg and subsequently standardised by Casagrande determines liquid limit as the water content at which 25 standard blows are required to cause closure of a standard groove. In order to speed up the determination of the liquid limit, a single-point method is defined in ASTM D4318, and in many other codes, to interpret liquid limit from groove closure at a different numbers of blows by assuming a relationship between water content and the number of blows required for groove closure. These methods differ considerably between different codes of practice currently in use worldwide. This paper examines the procedures for single-point determination of the liquid limit and offers some fundamental explanations that underpin the applicability of these procedures. This paper demonstrates that the variation in single-point liquid limit procedures suggested by various codes of practice can be attributed to the variability of liquid limit devices, rather than to variation in the soils being tested.

We classify soils to group our knowledge, increase our understanding, and communicate results. I have analyzed
how soil classification and factor and soil property naming have been used in journal papers between 1975 and
2014. There is an exponential increase in the use of Taxonomy and WRB but the increase in the number of soil science
papers is much faster than the use of Soil Taxonomy and WRB. The percentage of papers with soil classification
information was highest in Geoderma (34%). The soil biology journals had soil classification in only 6% of their
papers. Soil Taxonomy seems to be more frequently included particularly in journals from the USA, whereas FAO-
Unesco and WRB are more frequently used in European journals. Soils in dry areas (Aridisols, Calcisols, Gypsisols)
seem to be under-researched, whereas Spodosols (Podzols), Vertisols, Anthrosols, Chernozems, and Luvisols
seem over-represented. Soil factor and property naming (e.g. "agricultural soil", "sandy soil") increase faster
than the use of Soil Taxonomy and WRB. Temperate and boreal soil is commonly used in Soil Biology and Biochemistry
which also tops the number of papers with forest soil, "agricultural soil", "upland soil", "wetland soil", and
"valley soil". The more geologically oriented journals use parent material terms like "alluvial soils" and "granite
soils". Color soil naming is common in some Chinese (black soil, red soil) and Canadian journals (Brown soil).
Problems of soil classification are related to technical issues of soil classification, the adoption of the system,
and the lack of instructions in soil science journals. A lack of soil classification in our papers makes transfer of information,
data and results difficult.

Soil Sequences Atlas III is a continuation of two earlier volumes published in 2014 and 2018. As in the previous studies, the variability of soil cover is presented in the form of soil sequences characteristic of particular types of landscapes. Each of the chapters contains a general description of the environment (lithology, topography, land use, climate), a set of soil data (soil profile photo, description of morphology, laboratory data) and their interpretation in terms of the pedogenesis and systematic position according to the WRB (2015) system. The “catenary approach” (expressed in the form of individual figures) helps to better understand the relationships between individual components of the environment and soils. Chapters are arranged roughly according to the main soil-forming process in sequences and referring to the World Reference Base for Soil Resources except for Technosols, which as “unnatural” soils are placed at the end of the book. At the beginning of the book, two landscapes dominated by Gleysols and gleyic processes were described – tidal flats in Germany and the flood plain of the Vistula River in Poland. Next, the mountain areas with Andosols (Slovakia), Lithosols and Podzols (Poland) were presented. The issue of the environment with the dominant podsolization process was continued in the subsequent chapters from Lithuania and Russia. Chapters 8 and 9 are related to Hungarian and Ukrainian soils with a pronounced accumulation of humus in epipedons (Chernozems, Umbrisols, Phaeozems). The book ends with a section on issues related to clay-illuviated (Luvisols), coarse textured (Arenosols) and technogenic (Technosols) soils in Poland, Estonia and Czechia. Sixteen Reference Soil Groups are featured, and represented by 61 soil profiles in total. One of the objectives of the Soil Sequences Atlas is to explain the relationships (predictable to some extent) between the landscape and soil cover. The collected data are intended to be a useful educational tool in the teaching of soil science, supporting the understanding of the causes of soil cover variability, and also as a WRB classification guideline. They are intended to be useful not only to students but also practitioners in agriculture, forestry, environmental protection and landscape planning. The Atlas was developed as part of the EU Erasmus+ FACES project (Freely Accessible Central European Soil).

The study was aimed at the characterizing and the classifying of soils of Jalingo metropolis in Taraba State, NorthEast Nigeria. Profile pit was dug on each of the three different sites of the study area as identified using free survey. The profile pits were described and sampled bases on horizon differentiation for laboratory analyses. A total of 10 samples were collected. Data generated were analyzed using descriptive statistics to determine their coefficient of variation. The result indicated that the horizons were mostly reddish when moist at different contrasting level. The textural classes were mostly loamy sand while the sub-angular blocky structure was observed in the entire subsurface horizons. The horizons of the pedons were well drained. Sand fraction had means of 826.80 g/kg, 816.80 g/kg and 766.8 g/kg for pedons 1, 2, and 3 respectively. Clay fraction increased in an increasing soil depth which formed an argillic horizon. Sand fraction, bulk density and particle density recorded low variation (≥0 % ≤5.22 %) in among the pedons. Soil pH(H 2 O) had a mean of 6.40 in pedon 1, 6.43 in pedon 2 and 6.41 in pedon 3. Organic carbon ranged from ≥2.0 g/kg ≤0.43 g/kg while cation exchange capacity ranged from ≥4.58 cmol/kg ≤5.01 cmol/kg among the pedons. The percent base saturation had a mean of 66.6 %, 65.1 % and 66 % in pedon 1, 2 and 3. Hence, pedons 1 and 2 were classified as Grossarenic Kandiustalfs (Arenic Lixisols), while pedon 3 was classified as Arenic Kandi-ustalfs (Loamic Lixisols) according to USDA soil taxonomy and correlated with world reference base.

Vardanega, P.J. & Haigh, S.K. (2017). Discussion of "Water Content Ratio: An Effective Substitute for Liquidity Index for Prediction of Shear Strength of Clays" by Beshy Kuriakose, Benny Mathews Abraham, A. Sridharan & Babu T. Jose. Geotechnical and Geological Engineering, 35(6): 3039-3044 https://doi.org/10.1007/s10706-017-0290-0

The problem of forecasting in general and in real-time of the behaviour of seismic wave is discussed. A hybrid model for real-time forecasting of strong motion acceleration on the bases of general, tectonic, seismic and site parameters is developed. On the base of this forecasting can be made right decision for activating different devices and systems for passive, active or hybrid structural control for protection of high risk structures like power plants, in particular nuclear power plants. The numerical simulation was made with different program package like Fuzzy TECH 5.51, MatLab 6.5 and Simulink.