Influence Of Soil Type Research Articles

Can neotectonic faults influence soil air radon levels in the Upper Rhine Graben? An exploratory machine learning assessment

Radon (Rn) is a naturally occurring radioactive gas that poses a significant lung cancer risk. Subsurface fault zones can act as pathways for fluid and gas migration, potentially amplifying Rn accumulation. This study investigates the impact of fault zones on Rn concentrations within a 25 km2 area in the Northern Upper Rhine Graben, Germany — a region with available detailed geophysical exploration data and active neotectonic faulting. We conducted 597 Rn soil air measurements along precisely located fault zones, integrating a comprehensive range of environmental parameters. Utilizing the advanced machine learning model eXtreme Gradient Boosting (XGBoost) in conjunction with SHapley Additive exPlanations (SHAP) values, we dissected the influence of soil types, environmental factors, and proximity to fault zones on soil air Rn concentrations at a 1-meter depth. Our results reveal that clay-rich soils and cumulative 30-day precipitation are the primary drivers of elevated Rn levels. Proximity to fault zones also significantly influences Rn concentrations, though its impact is less pronounced than the factors mentioned above. Additionally, environmental factors such as wind speed, air pressure, and temperature exhibited lesser effects on Rn levels. The negligible influence of measuring devices and operating personnel increases confidence in data integrity in extensive environmental studies. This study demonstrates the effectiveness of integrating XGBoost with SHAP values to identify and quantify key factors influencing Rn concentrations. By providing a robust framework for enhancing Rn prediction models through machine learning, our findings contribute to improved risk assessments and mitigation strategies, thereby advancing public health and environmental management.

Global reliability assessment of coupled transmission tower-insulator-line systems considering soil-structure interaction subjected to multi-hazard of wind and ice

This study aims to assess the global reliability of coupled transmission tower-insulator-line systems considering soil-structure interaction (CTTILSs-SSI) subjected to multi-hazard of wind and ice. Firstly, two simplified models of CTTILSs-SSI under stochastic wind and ice loads are established, and their governing equations are derived through the Lagrange equation. On this basis, a global reliability assessment framework of CTTILSs-SSI is proposed based on the improved maximum entropy method, in which the global performance function of CTTILSs-SSI is defined via the state variable description method. Finally, a practical ultra-high voltage overhead transmission line located on the icing zone is chosen to illustrate the proposed framework. Moreover, to investigate the influence of soil-structure interaction (SSI) and soil types on the global reliability of transmission tower-insulator-line systems (TTILSs), the global reliability of CTTILSs-SSI with various soil types is compared with that of a fixed base system. The results indicate that under the in-plane wind and ice loads, the global failure probability of TTILSs is almost zero, and it is essentially not affected by the SSI effect and soil types. However, under the out-of-plane wind and ice loads, the global failure probability of CTTILSs-SSI is higher than that of the fixed base system, and the global failure probability of CTTILSs-SSI increases as the soil stiffness decreases. Accordingly, it may be more reasonable to consider the SSI effect into the global reliability analysis of TTILSs subjected to ice and out-of-plane wind loads, particularly when the soil is soft.

Effects of Soil Type, Irrigation Method, and Biomass Application on Grain Yield and Its Determinants in Irrigated Lowland Rice of Agusan

Information about the influence of soil type, irrigation method, and biomass use on rice productivity in Agusan is insufficient, despite their importance in developing or improving irrigated lowland rice production. Hence, this study determined the influence of these factors on grain yield and yield-contributing crop traits. It also explained grain yield based on yield determinants and recommended water management for improving grain yield. The greenhouse experiment was laid out in a three-factor randomized complete block design with 10 replications. The treatments were [a] Butuan sandy loam soil (SLS) and Butuan loam soil (LS); [b] continuously flooded (CF) and controlled irrigation (CI); and [c] applied and unapplied biomass. Data on grain yield and yield determinants were gathered weekly, during harvesting, and after harvesting. Relative to LS, SLS had a statistically greater grain output owing to its higher root and water permeability and better balance among soil nutrients, leading to closer-to-the-optimum soil nutrient uptakes and better yield-contributing crop traits. Compared with CI, CF had a statistically superior grain output as it induced the crop to produce more robust tillers, leading to significantly better yield-contributing crop characteristics. Biomass application modified the soil type x irrigation method interaction since the degree at which CF was exhibiting higher grain yield than CI was significantly greater in SLS than LS for experimental units or pots applied with biomass. Moreover, the level at which CF was attaining greater grain yield than CI was statistically similar in SLS and LS for pots unapplied with biomass. It is therefore recommended that rice be grown in Butuan sandy loam instead of Butuan loam, and that CF instead of CI be used in soil with a mild zinc deficiency or sufficient zinc status.

Thermo-hydro-mechanical behaviour of energy tunnel in unsaturated soils

Soils surrounding energy tunnels are often unsaturated, particularly in areas with a low water table. All studies of the mechanical behaviour of energy tunnels focused on saturated or dry soils. Through numerical simulations using a coupled thermo-hydro-mechanical model for unsaturated soils, this study aims to improve the understanding of the interactions between energy tunnels and unsaturated ground. The influences of water table position and soil type on the mechanical behaviour of energy tunnels were investigated. Results show that the thermally-induced lining convergence of energy tunnels does not change much with the water table position. Nevertheless, the other mechanical responses (e.g., settlements of ground and tunnel and lining stress changes) highly depend on the water table position. These mechanical responses are more significant when the water table is higher than the tunnel center, except for the larger settlements at a lower water table in clay. Furthermore, the above responses are underestimated if soils above the water table are assumed to be completely dry. The degree of underestimation is most significant for the clay, followed by silt and sand, e.g., a maximum of 54%, 23% and 10% in the change of circumferential stress, respectively. These results highlight that the unsaturated soil model should be used to evaluate the thermo-hydro-mechanical responses of energy tunnels in unsaturated soils, particularly for the clay ground.

The influence of soil types and agricultural management practices on soil chemical properties and microbial dynamics

Soil provides essential nutrients for plant growth, but excess salts hinder development, making crops more vulnerable under climate change conditions. Soil microorganisms play a significant role in nutrient cycling. However, limited information is available on microbial behavior/community changes, and functional diversity in different soil types (normal, sodic, and highly sodic) and cropping systems [rice-wheat (RW); rice-wheat-mungbean (RWMb); maize-wheat-mungbean (MWMb)] and management practices in the north-western Indo-Gangetic Plains of India. We investigated the influence of different soil types on physical and chemical properties at the surface level (0–15 cm) in relation to soil microbial population, activities, and functional diversity, focusing on community-level physiological profiling (CLPP) under different agriculture systems. Seven treatment combinations of soil types, cropping systems, and management practices were evaluated. Soil pHs were found to be lower in zero-till (ZT)-based sodic soil than in conventional-till (CT) sodic soil. Soil organic carbon (SOC) (0.91 and 0.90%) content and available N (154.46 and 132.74 kg ha−1) were higher with the ZT-based system under normal (N) soils (ZT-RWMb-N and ZT-MWMb-N) than in CT-based normal soil (0.67 and 121.04 kg ha−1). Similarly, higher SOC and N (0.85 and 76.11 kg ha−1) were found under ZT management in sodic soils (S) than under CT management (0.73% and 121.05 kg ha−1). Substrate utilization (amino acids, amines, carbohydrates, carboxylic acids, phenolic compounds, and polymers) increased with the incubation period. During 0–120 h of incubation, the highest utilization of amino acids, amines, carboxylic acids, phenolic compounds, and polymers was observed for ZT-MWMb-S soils, while the lowest was recorded for ZT-MWMb-N soils. Under high salt conditions, soil enzymatic activities (dehydrogenase, acid phosphatase, alkaline phosphatase, etc.) declined significantly compared to normal soils, affecting soil chemical and physical conditions. Microbial population and enzyme activities decreased with increasing salt stress across all cropping systems. These findings suggest that adopting efficient crop management practices can help mitigate the adverse effects of soil salinity on microbial diversity and soil health, thereby enhancing sustainable agricultural productivity in salt-affected regions.

A new SPT-CPT correlation by statistical analysis based on a database from Anhui, China

ABSTRACT The standard penetration test (SPT) and cone penetration test (CPT) are the 2 most commonly used in situ tests in geotechnical investigations. In this study, various existing SPT–CPT correlations were assessed based on the database of Anhui Province, China, using data from 802 pairs of SPT–CPT measurements. The results showed that the existing correlations from other regions were not suitable for the geological conditions in Anhui Province. A new SPT–CPT conversion model based on the S curve was proposed through statistical analysis. This model introduced the soil behaviour index (Ic ) to SPT–CPT correlations to involve the influence of soil types on data interpretation. Comparative analysis demonstrated that the proposed correlation had the highest accuracy compared to correlations found in the literature, with the highest R2 value and lowest RMSE. Also, to validate the proposed model further, an additional set of investigation data was collected in Wuhu, Anhui, to verify the correlation. The correlation was successfully applied to predict a range of soil properties using the transformed N60 values. The validation analysis confirmed the highest accuracy of the correlation and its ability to effectively predict soil properties, thereby assisting in geotechnical design.

Influence of Soil Type and Moisture on Pupal Development of Chrysomya rufifacies (Macquart) at Two Different Temperatures.

The present study investigates the developmental process of Chrysomya rufifacies (Macquart) pupae and their dependency on soil composition, moisture levels, and temperature changes. This research holds implications for forensic and veterinary applications, providing crucial insights for estimating minimum postmortem intervals and managing myiasis-causing flies in diverse environments. Specifically, the study explores the impact of five moisture content levels in loam and sandy soils (0%, 20%, 40%, 60%, and 80%) on the pupal development of Ch. rufifacies under two distinct constant temperature regimes (24 ± 1 °C and 30 ± 1 °C). A significant correlation was observed between soil type and temperature regarding the time required to complete the pupal stages; however, moisture had no significant impact. Larvae exhibited varying survival rates across the two temperatures and five moisture levels in the two types of soils, particularly under extremely lower moisture conditions (0%) at 30 ± 1 °C, failing to progress to the pupariation stage. Additionally, growth parameters such as pupal length and width of the fully formed puparia were significantly impacted by temperature, soil type, and moisture level. Adult head width was systematically measured across different moisture levels and soil types, revealing distinct temperature-dependent responses. Furthermore, a sex-specific analysis highlighted that female Ch. rufifacies consistently displayed larger head widths and higher emergence rates compared to their male counterparts. This research enhances our understanding of the intricate interrelationship among three environmental variables: soil type, moisture level, and temperature, elucidating their collective impact on the pupation processes of dipterans.

Exploring the Influence of Soil Types on the Mineral Profile of Honey: Implications for Geographical Origin Prediction.

Honey contains a wide range of inorganic substances. Their content can be influenced, i.e., by the type of soil on which the bee pasture is located. As part of this study, the mineral profile of 32 samples of honey from hobby beekeepers from the Czech Republic wasevaluated and then compared with soil types in the vicinity of the beehive location. Pearson's correlation coefficient was used to express the relationship between mineral substances and soil type. There was a high correlation between antroposol and Zn (R = 0.98), Pb (R = 0.96), then between ranker and Mn (0.95), then regosol and Al (R = 0.97) (p < 0.05). A high negative correlation was found between regosol and Mg (R = -0.97), Cr (R = -0.98) and between redzinas and Al (R = -0.97) (p < 0.05). Both positive and negative high correlations were confirmed for phaeozem. The CART method subsequently proved that the characteristic elements for individual soil types are B, Ca, Mg, Ni, and Mn. The soil types of cambisol, fluvisol, gleysol, anthrosol, and kastanozem had the closest relationship with the elements mentioned, and it can therefore be assumed that their occurrence indicates the presence of these soil types within the range of beehive location.

Impacts of soil type and drought stress on growth and cesium accumulation in Napier grass.

In our previous study, the decontamination efficiency of cesium-137 (137Cs) by Napier grass (Pennisetum purpureum Schum.) in the field was shown to be variable and often influenced by natural environmental factors. To elucidate the factors influencing this variable 137Cs-decontamination efficiency, we investigated the influences of soil type and drought stress on Cs accumulation using cesium-133 (133Cs) in Napier grass grown in plastic containers. The experiment was performed using two soil types (Soil A and B) and three different soil moisture conditions: well-watered control (CL), slight drought stress (SD), and moderate drought stress (MD). Overall, our results indicate that soil type and drought have a significant impact on plant growth and 133Cs accumulation in Napier grass. Plant height (PH), tiller number (TN), leaf width (Wleaf), and dry matter weight of aboveground parts (DWabove) and root parts (DWroot) in Soil B were greater than those in Soil A. Drought stress negatively affected chlorophyll fluorescence parameters (maximal quantum efficiency of photosystem (PS) II photochemistry and potential activity of PS II), PH, TN, Wleaf, DWabove, DWroot, and total 133Cs content (TCs), but it had a positive effect on 133Cs concentration. The 133Cs concentration in the aboveground parts (Csabove) was increased by MD approximately 1.62-fold in Soil A and 1.11-fold in Soil B compared to each CL counterpart. The TCs in the aboveground parts (TCsabove) decreased due to drought by approximately 19.9%-39.0% in Soil A and 49.9%-62.7% in Soil B; however, there was no significant effect on TCsabove due to soil type. The results of this study indicate that soil moisture is a key factor in maintaining Napier grass 137Cs-decontamination efficiency.

An improved analytical solution for solving the shield tunnel uplift problem

The problem of shield tunnel uplift is a common issue in tunnel construction. Due to the decrease in shear stiffness at the joints between the rings, uplift is typically observed as bending and dislocation deformation at these joints. Existing modeling methods typically rely on the Euler-Bernoulli beam theory, only considering the bending effect while disregarding shear deformation. Furthermore, the constraints on the shield tail are often neglected in existing models. In this study, an improved theoretical model of tunnel floating is proposed. The constraint effect of the shield machine shell on the tunnel structure is considered using the structural forms of two finite long beams and one semi-infinite long beam. Furthermore, the Timoshenko beam theory is adopted, providing a more accurate description of tunnel deformation, including both the bending effect and shear deformation, than existing models. Meanwhile, the buoyancy force and stratum resistance are calculated in a nonlinear manner. A reliable method for calculating the shear stiffness correction factor is proposed to better determination of the calculation parameters. The proposed theoretical model is validated through five cases using site-monitored data. Its applicability and effectiveness are demonstrated. Furthermore, the influences of soil type, buried depth, and buoyancy force on the three key indicators of tunnel floating (i.e. the maximum uplift magnitude, the ring position with the fastest uplift race, and the ring position with the maximum uplift magnitude) are analyzed. The results indicate that the proposed model can provide a better understanding of the floating characteristics of the tunnel structure during construction.

Influence of soil type and ripening degree on the intensity and sensory dominance of Mexican habanero chili (Capsicum chinense Jacq.)

AbstractThe objective of this research was to determine the intensity and sensory dominance of habanero peppers grown in different types of soils and with different degrees of maturation. Chili samples grown in red soil (Mayan name: K'ankab lu'um) and black soil (Mayan name: Box lu'um) were evaluated in an immature state (green coloration) and intermediate ripening (green‐orange coloration) using descriptive analysis (DA) and temporal dominance of sensations (TDS). Sensory representation and classification percentage of chili peppers were evaluated using principal component analysis and discriminant factor analysis. The sensory results demonstrated that intermediate ripening chili peppers presented higher color intensities associated with pungency. Immature chili peppers were characterized by having high odor intensities. The TDS results showed that the dominant attributes were burn feeling, chili flavor, heat, and numbness. Immature chili peppers grown in black soil tend to be burn feeling dominant and chili peppers grown in red soil were characterized as chili flavor. The ripe habanero peppers were chili flavor burn feeling and heat. The correct classification percentage was 89.81%.Practical ApplicationsThis research exposes the sensory differences of habanero peppers with different degrees of maturation and grown in different types of soils. The findings can serve as a reference for future research on the sensory characterization of pungent and for the industry dedicated to the production of habanero chili and for the gastronomy area in charge of the preparation of different dishes that use habanero chili as an ingredient.

Using Machine Learning to Predict Axial Pile Capacity

Accurate estimation of the ultimate axial load bearing capacity of piles is necessary to ensure the safety of the supported structures and to prevent cost overruns. Traditional mechanics-based design methods do not always predict pile capacity accurately, or precisely, leaving room for improvement. This study focuses on the potential of machine learning (ML) in estimating pile capacity. A dataset of 546 load tests was compiled from three databases. The baseline performance of traditional design methods was first established by comparing the capacities computed using four traditional approaches, against the capacities interpreted from load tests using Davisson’s criterion. Sixteen different ML techniques were explored. First, the optimal feature selection technique for model training was investigated. Second, hyperparameters of each technique were optimized. The process involved the training of 32,000 different models and tuning their hyperparameters. Next the dataset was randomly split into training (70%) and testing (30%) for comparing the 16 different ML regression models. Each of the optimized models was then trained using six feature sets. The performance of each of the 16 ML models with the best performing feature subset was compared with the baseline performance from traditional methods. Evaluation criteria included measured versus predicted capacities, influence of soil type on accuracy, as well as the absence of pile diameter, or length effects on accuracy and precision. In general, the ML methods performed significantly better than the best traditional method. The current research demonstrated that ML may offer advantages in geotechnical design when large datasets are available.

Culturable Diversity of Endophytic and Rhizoplane Colonizing Bacteria of Indian Mustard (Brassica juncea (L.) Czern & Coss), Affected by Soil Types and Assessment of Plant Growth Promoting Attributes

Microbial community in the rhizosphere of plant significantly influences growth and development of a plant. As the soil vary in microbial composition due to interaction of soil with plant roots and its exudates, the role of soil in shaping microbial diversity of a crop rhizosphere is least studied. In present study, Mustard (Brassica juncea cv Pusa Mehak) was grown in three different soil viz. Vertisols, Inceptisols and Alfisols, and the bacteria were isolated form root tissues and rhizoplane to study their plant growth promoting (PGP) attributes and diversity using BOX-Polymerase chain reaction (PCR) fingerprinting technique, as influenced by soil types. Form threes soil orders, total 37 isolates were obtained of which, 19 could grow on nitrogen free medium, 6 solubilized P from tricalcium phosphate, 2 isolate solubilized potassium from glauconite and 8 had zinc solubilizing ability with the highest zinc solubilization index of 3.84 by isolate VRB-7. Based on the fingerprint analysis, differences occurred in the endophytic bacteria of same host grown in different soil types suggesting influence of soil types in colonization of microbes in rhizoplane and endorhizosphere. The common organisms obtained from host grown in different soil types indicating host genotype driven assembly of bacteria. Similarity in the isolates on rhizoplane and endorhizosphere indicated endophytic colonization of the isolates capable of firmly adhering to the rhizoplane. The findings of this study will help in formulation of crop specific bioinoculant for specific soil types and edaphic properties.

Influence of Soil Type and Temperature on Nitrogen Mineralization from Organic Fertilizers

Organic vegetable producers in Georgia, USA, utilize a range of amendments to supply nitrogen (N) for crop production. However, differences in soil type, fertilizers and environmental conditions can result in variability in N mineralization rates among commonly utilized organic fertilizers in the region. In this study, the effects of temperature on N mineralization from three commercial organic fertilizers [feather meal (FM), pelleted poultry litter (PPL) and a mixed organic fertilizer (MIX)] in two soil types from Georgia, USA (Cecil sandy clay loam and Tifton loamy sand) were evaluated for 120 d. Net N mineralization (Net Nmin) varied with soil type, fertilizer and temperature. After 120 d, Net Nmin from the FM fertilizer ranged between 41% and 77% of total organic N applied, the MIX fertilizer ranged between 26% and 59% and the PPL fertilizer ranged between 0% and 22% across all soil types and temperatures. Incubation at higher temperatures (20 °C and 30 °C) impacted Net Nmin of FM fertilizer in the Tifton series soil. Temperature and soil type had a relatively minor impact on the potentially mineralizable N of the PPL and MIX fertilizers after 120 d of incubation; however, both factors impacted the rate of fertilizer release shortly after application, which could impact the synchronicity of N availability and plant uptake. Temperature-related differences in the mineralization of organic fertilizers may not be large enough to influence a grower’s decisions regarding N fertilizer inputs for vegetable crop production in the two soils. However, organic fertilizer source will likely play a significant role in N availability during the cropping season.

Influences of Soil and Plant Types on The Mitigation Rate of Radium-226 in The Cultivated Soils

Influences of Soil and Plant Types on The Mitigation Rate of Radium-226 in The Cultivated Soils

The Assessment of the Influence of Soil Type on the Nonlinear Seismic Response of a Corroded Reinforced Concrete Portal Frame

Background: Most researchers have focused on the effect of rebar corrosion on the seismic behaviour of reinforced concrete (RC) columns. On the other hand, the influence of chloride corrosion of reinforced concrete in combination with soil type on the seismic behaviour of RC columns has not been investigated. Objective: This paper investigates the influence of soil characteristics on the seismic vulnerability of reinforced concrete structures. The case study in focus is a reinforced concrete portal frame with columns exhibiting corrosion at ground level. Methods: Chloride ingress initiates corrosion and reduces the cross-sectional area of the corroded concrete steel. In addition, this research considers two different soil types, namely rocky and loose, as relevant factors in the analysis. Firstly, the seismic loads are determined according to the Moroccan seismic building code RPS2011. Then, the evaluation of the evolution of the diameter of corroded bars due to chloride induced corrosion is investigated. Finally, pushover analysis is used to determine the location of the performance point on the capacity curve. Results: The study also includes an investigation of the ductility characteristics of corroded reinforced concrete structures and the inter-storey displacement in different soil conditions. The results show that the inter-storey displacement decreases with increasing age of the structure. In addition, it is observed that the base shear force and roof displacement at the point of failure are more sensitive in loose soils compared to rocky soils. Conclusion: The results indicate that consideration of soil type can significantly alter the expected seismic performance, resulting in higher vulnerability values.

Influence of Soil Types and Quantities of the Mixture of Hairy Woodrose (Merremia aegyptia L.) Plus Bovine Manure on the Agronomic Viability of Coriander in the Semiarid Region of Brazil

Aims: Coriander cultivation is an activity of great importance for family farmers in the Brazilian semi-arid region. In this sense, the objective was to study the influence of soil types and quantities of a mixture of hairy woodrose (Merremia aegyptia L.) and cattle manure on the agronomic viability of coriander in semi-arid region of Brazil.&#x0D; Place of Study: The experiment was carried out in the greenhouse of the Agricultural and Forestry Sciences department of the Universidade Federal Rural do Semi-Árido, Brazil.&#x0D; Study Design and Methodology: The design used was completely randomized in a 4 x 2 factorial scheme, with three replications, being the first factor consisting of four quantities of the mixture of hairy woodrose (Merremia aegyptia L.) plus cattle manure (0.0; 1.5; 3.0; 4.5 and 6.0 kg m-2 of area) and the second factor consisted of two types of soil (latosol and an argisol) in single cultivation.The coriander cultivar "Frevo" was used, adapted to the edaphic and climatic conditions of the semi-arid region. The spacing used was 0.1 x 0.05 m with five plants pit-1, corresponding to 1000 plants m-2 of area. After harvesting the coriander, the following characteristics were evaluated: plant height (expressed in cm plant-1); number of stems (expressed in plant-1 units); productivity (expressed in grams m-2 of area); number of bunches (expressed in plant-1 units) and dry mass (expressed in grams m-2 of area).&#x0D; Agronomic Characteristics of Coriander: Plant height (expressed in cm plant-1); number of stems (expressed in units plant-1); productivity (expressed in grams m-2 of area); number of bunches (expressed in units plant-1) and dry mass (expressed in grams m-2 of area).&#x0D; Conclusions: There was no interaction between the factors studied, with the amount of 3.0 kg m-2 of the hairy woodrose (Merremia aegyptia L.) mixture with cattle manure, promoting the greatest increase in coriander cultivation, with values of 1030.6 g m-2, equivalent to 20.87 units of coriander bunches m-2, respectively. In relation to soil types (latosol and an argisol) there was no statistical difference, with values of 841.9 and 709.6 g m-2 for productivity, equivalent to 16.7 and 14.0 units of coriander bunches m-2.

Investigation and Slope Improvement of Landslides on Bodor River Slopes

The Bodor River is an important source of rice irrigation because most of the population works in the agricultural sector. The slopes of the Bodor River have experienced landslides, causing a major negative impact on the community. Many studies state that soil type, consistency, and friction angle influence slope failure. However, the relationship between soil characteristics and landslides on slopes, especially on the Bodor River, has not been studied. This research aims to identify soil characteristics and their influence on landslides on the slopes of the Bodor River, along with recommendations for improvement. The soil was taken after a landslide occurred at a depth of 80 cm for a sieve gradation test, Atterberg limit test, direct shear test, and slope stability analysis using the Cullman method. The research results show that the SW-SM soil type on the slopes of the Bodor River is highly vulnerable to landslides. A steep slope of 50° and a low soil friction angle between 1.38 and 14.11 have less than one safety factor. Changes in soil conditions, such as increased water content, contribute to a higher risk of landslides. Therefore, strengthening the slope is necessary, with the recommendation to increase the slope to 34.5° so that the slope safety factor increases by 73%. The results of this research provide an overview of the relationship between geotechnical soil parameters that influence slope failure in river areas and recommendations for slope improvement to prevent future collapse.

Mineralisation and priming effects of a biodegradable plastic mulch film in soils: Influence of soil type, temperature and plastic particle size

There is increasing use of biodegradable mulch films (BDMs) as an environmentally sustainable alternative to traditional mulch films in agriculture. However, their degradation fate and priming effect (PE) on native soil organic matter (SOM), including in the form of microplastics (MPs) after disintegration, are not well known. In this study, we investigated mineralisation of a BDM (0–2000 μm MPs) and its PEs in three soils, i.e., a Ferralsol, a Vertisol and a Solonetz. The MPs were incubated at a concentration of 0.8% (w/w) separately in the three soils at three temperatures i.e., 20, 30 and 40 °C for 150 days. We also evaluated the effect of BDM MP particle size on its mineralisation and PEs in two soils (a Ferralsol and a Vertisol). Six size fractions (i.e., <100, 100–250, 250–500, 500–1000, 1000–2000, 2000–4750 μm) were incubated in the soils at 30 °C for 150 days. A δ13C technique was employed to determine the proportion of C mineralised from MPs and SOM owing to their distinct δ13C values. Temperature, soil type, particle size and their interactions were all key factors in the mineralisation of MPs and PEs. The mineralisation of MPs increased with the increasing temperatures from 20 to 40 °C in the three soils over time with few exceptions. At 20 and 40 °C, the Ferralsol with greater carbon and clay content showed greater MP mineralisation than the Vertisol and Solonetz. Opposite trends were observed for the MP mineralisation and PEs in the Vertisol at 20 and 30 °C and in the Ferralsol at 20 °C. However, at 40 °C, both MP mineralisation and PEs exhibited similar trends in the three soils suggesting that a ‘co-metabolism’ may be dominant at high temperatures. Furthermore, we observed that smaller MPs tended to induce greater mineralisation, whereas the larger MPs caused greater PEs than small particles.

Analysis of the influence of different soil types on the natural frequencies of multi-storey reinforced concrete buildings

According to current concepts, the construction of multi-storey and high-rise buildings is quite topical. Increasing the number of storeys and building density provokes an increase in loads and forces on the structural elements of the building, as well as on the soil base. It is necessary to take into account the mechanical characteristics of the soils underlying multi-storey buildings to improve the design models of objects when determining the forces and deformations in their elements. A vital indicator in monitoring the structural characteristics of buildings is global stiffness. Natural frequencies determined by modal analysis are used to detect its change. The purpose of this study is a numerical analysis of the effect of changes in the parameters of the soil base on the natural frequencies and values of vibrations of multi-storey reinforced concrete frame buildings using software systems. In this study, four variants of design models with rigidly fixed foundations and elastic foundations with different types of soils were developed.In the models with elastic foundations, stable soils were used, such as sandy, moderately stable, represented by loams and sandy loams, and weak soils containing a layer of peat. The building scheme was developed using the SCAD software package with the application of the finite element method. Taking into account that 90% of the territory of Ukraine is located in complex engineering and geological conditions, the use of the finite element method allows to effectively solve complex problems of interaction of heterogeneous elements, including in a nonlinear approach. As a result, it was found that the type of soil foundation affects the change in the natural vibration frequencies of a building. In the model with a rigidly fixed foundation, the frequencies are the highest, and the eigenvalues of oscillations are the lowest. A point that should be mentioned is that in the variants with an elastic foundation, the lowest frequencies are observed in the model on weak soils, and the highest values are typical for sandy foundation soils.