Soil Loading Research Articles

The Effect of Soil Load Variations on Cone Penetration Results in Shallow Foundation Dimensions: Case Study

The purpose of this study is to determine the variation of load values ​​on shallow foundations applied to short-span bridges in the Kutalimbaru Bridge Project, Deli Serdang Regency and the depth value has been obtained from cone penetration results, and to determine the value of the Kutalimbaru bridge floor plate. The variation of the value indicates per 10% of the actual value until it reaches the limit of the value used. The cone penetration test on this bridge was taken from 2 points with a depth of S-1 3.2 m and S-2 2.2 m. The test results show a Cone Penetration Resistance value of S-1 250 kg / cm2 and a Total Shear Resistance of 720 kg / cm S-2 250 kg / cm2 and a Total Shear Resistance of 420 kg / cm. So, the type of original soil is predominantly rocky sand with a little clay. The results of the analysis show that shallow foundations can withstand loads up to 98, 634 tons, with a foundation soil stress of 3.41 kg / cm2 and a soil allowable stress of 3.33 kg / cm2. The control value of the thickness of the bridge floor slab for K350 concrete quality, and for the permissible punching shear stress is 12.16 kg/cm² and the punching stress that occurs is 2.81 kg/cm which is smaller than the thickness value of the bridge floor slab. Keywords: Shallow foundation, bridge, cone penetration .

Comparative Study of the Influence of the Fish Coefficient and Young's Modulus with the Hardening Soil Model and The Mohr-Coulomb Model on the Behavior of Cable-Stayed Bridge Piles

This article deals with the behavior of isolated piles subjected to two models used in geotechnics (Hardening Soil and Mohr Coulomb) under cyclic lateral loading and their head deformations compared to monotonic loading in sandy soil. The behavior of the cable-stayed bridge piers was predicted using PLAXIS 2D software, based on the results of in situ and laboratory geotechnical studies carried out by the control office for Building and Public Works (BCBTP). Numerical simulation is an alternative to the high cost of large-scale in situ and laboratory studies for describing the behavior of deep foundations. The results obtained show that piles subjected to lateral head loading cause a horizontal head displacement compared with the Hardening Soil and Mohr Coulomb models. Cyclic loading of a pile results in deformation of the soil mass at the surface. Lateral displacement increases with the first few cycles until it stabilizes, generating an irreversible residual displacement due to progressive soil plasticization. Lateral cyclic loading has a favorable influence on pile behavior under cyclic loading, due to the reversible effect on pile displacement.

Plate Size Effects in Gravelly Soil Based on In Situ Plate Load Tests and Finite Element Analysis

The average contact stress–settlement behavior observed in plate load tests provides essential data for reliable foundation design. However, the test plate is often smaller than the actual foundation, requiring size extrapolation to interpret in situ plate load test results accurately. This study combines in situ plate load test results in gravelly soil with finite element analysis to evaluate test plates of varying sizes. The findings suggest that the coefficient of subgrade reaction for gravelly soil foundations can be effectively estimated using Terzaghi’s extrapolation method for the coefficient of subgrade reaction in clay. Although variations in test plate diameter may alter the shape of the average contact stress–settlement curve, the overall pattern of change remains consistent. The average contact stress–settlement relationship in gravelly soil can be represented by a three-phase linear model, corresponding to the elastic, yield, and failure stages. Additionally, while the elastic limit load in gravelly soil remains unaffected by plate size, the ultimate bearing capacity increases with larger plates before stabilizing.

Structural quality of a Latosol cultivated with oilseed in succession to soybean

Understanding the changes in soil structure that develop from oilseed crop successions is vital for successful production. The objective of this study was to evaluate the effects of different oleaginous crop successions on the least limiting water range and load-bearing capacity of a clayey Rhodic Hapludox. The following oilseed crops were cultivated under a no-tillage system in autumn-winter: sunflower (Helianthus annuus L.), canola (Brassica napus L. and Brassica rapa), safflower (Carthamus tinctorius L.), crambe (Crambe abyssinica Hochst.) and niger seed (Guizotia abyssinica). They were sown after soybean and soybean/corn (summer/fall-winter). When the autumn-winter crops flowered, soil samples with structure intact were collected at the 0.0–0.5 m and 0.5–0.10 m depths in metal cylinders. It was observed that in terms of water interval, the poorest soil structural quality in the 0.0–0.5 m layer was provided by the corn/safflower and corn/crambe successions. In terms of soil water content, the optimal time for soil management practices varied for the different oilseeds succeeding soybean. Soil load capacity varies inversely with water content and directly with soil density. Niger grown during autumn-winter in succession to soybean improved Rhodic Hapludox structure more than the other crop successions.

Pencegahan Keruntuhan Progresif pada Struktur Jembatan Tinjomoyo dari Analisis Hidrologi dan Geoteknik

This study aims to analyze measures to prevent progressive collapse of the Tinjomoyo Bridge in Semarang through hydrological and geotechnical approaches. The research employs a quantitative method with a descriptive approach to evaluate issues encountered in the field. The study includes an analysis of the impact of adding crib structures on riverbank slopes to mitigate scouring caused by water flow and redesigning the bridge pier foundation structure based on soil investigation data and loading conditions. Hydrological analysis indicates that a downstream weir slope of 20% effectively directs water flow to prevent damage to the slopes and bridge piers. Simulations using Plaxis 8.2 reveal that adding crib structures to the riverbank reduces longitudinal displacement by 269.07 mm. Furthermore, the structural safety factor increases from 10.774 (initial condition) to 12.024 (engineered condition). From a geotechnical perspective, redesigning the pier foundation using bored piles with a diameter of 1 meter and 12 pile groups effectively supports the applied loads. Based on the analysis, the proposed crib and foundation design are recommended as solutions to prevent progressive collapse of the Tinjomoyo Bridge. This solution is expected to provide long-term safety and stability for the bridge structure.

Study on mechanical properties and microscopic mechanism of fibre-modified subgrade soil under freeze–thaw cycles

ABSTRACT In order to solve the problem of low freeze-thaw deformation strength of railway road genes in cold regions, railway subgrade soil was improved with polypropylene fibres. The failure mechanism of fibres improved foundation soil is revealed by experiments. The test results showed the following: (1) The strength decreased with the increase in the water content in the melting state and reached its maximum when the water content was 12% in the freezing state. The strength reached the maximum when fibre incorporation was 0.3% and fibre length was 15 mm. (2) The shear strength of the improved subgrade soil gradually decreased and tended to be stable with the increase in the number of freeze–thaw cycles in the frozen state. There was no significant change with the increasing number of freeze–thaw cycles in the thawing state. (3) Before and after the cyclic loading of the fibre-modified subgrade soil, the strength after cyclic loading was greater than that before. (4) Through scanning electron microscopy, the optimal fibre content was determined to be 0.3%. The research results can provide a strong reference for the improvement of railway subgrades, and they have broad application prospects.

Antibiotics Resistance and Abundance of Some Bacteria from Agricultural and Non-agricultural Soil in One of the Most Agriculturally-active Settings in West Cameroon

Background: Agriculture is also concerned with the problem of bacterial resistance because agricultural soils are reservoirs of antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes. Objective: An investigation about ARB was carried out on agricultural soils in Mangoum, a neighborhood of the Foumbot municipality (Noun division, West Cameroon). Methods: It was conducted as a cross-sectional descriptive study with a total of 46 soil specimens collected from plant farms and a control plot. Isolation, enumeration and antibiotic susceptibility tests were performed according to standard protocols. Results: The bacteria recovered included Aeromonas spp., Chryseobacterium spp., Pseudomonas spp., Staphylococcus spp., and Gram-positive rods. Their loads in the farmland soils were significantly lower than in the control plot. Overall, susceptibility tests performed with 169 bacterial colony morphotypes revealed high resistance rates. Also, most of the isolates expressed multidrug-resistance to the antibiotics used, while highest resistance rates were recorded with isolates form agricultural plots. Levofloxacin, Imipenem, Gentamicin and Ciprofloxacin were globally the most effective. Conclusion: Agreeing with previous surveys conducted on animal farms, these findings could provide support to the sustainable orientation of policies regarding the control of antimicrobial resistance in Cameroon from the One Health perspective.

Efficacy of copper-impregnated antimicrobial surfaces against Clostridioides difficile spores.

Clostridioides difficile (C. difficile) is one of the most common causes of healthcare-associated infections (HAIs). Elimination of C. difficile spores is difficult as they are resistant to common hospital-grade disinfectants. Copper-impregnated surfaces provide continuous reduction of multiple pathogens, potentially lowering the risk of infections. This manuscript aims to evaluate the efficacy of copper-impregnated surfaces on C. difficile spores. Control (no copper) coupons and copper coupons containing 20% copper-oxide were inoculated with C. difficile spore loads ranging from 105 to 107 spores, with or without 5% fetal bovine serum soil load. After 4 hours of contact time, the C. difficile spores were recovered, plated on C. difficile growth media, and colony forming units were counted. The efficacy of copper (log10 kill) was estimated using a Bayesian latent variables model. After 4 hours, unsoiled copper bedrail and copper table coupons at mean spore inoculation resulted in a 97.3% and 96.8% reduction in spore count (1.57 and 1.50 log10 kill, respectively). That of soiled bedrail and table coupons showed a 91.8% and 91.7% reduction (1.10 and 1.10 log10 kill, respectively). Copper coupons can substantially reduce C. difficile spores after 4 hours, but results vary depending on the initial spore concentration and presence or absence of organic material. Higher initial spore loads or excess organic material may prevent spores from contact with copper surfaces, thus decreasing kill efficacy. Continuous sporicidal effect of copper-impregnated surfaces may decrease spore burden and help prevent transmission of spores.

Evaluating the Share of Atmospheric Deposition of Priority Pollutants Cadmium and Lead in Soil Pollution with the Use of Ombrotrophic Peat Bogs as Natural Archives

Sustainable soil resource management requires detailed knowledge of soil pollution sources and their share in total pollution level. Spatial pollution caused by the total cumulative atmospheric deposition remains largely unknown, as the biggest pollutant emissions occurred in XIX/XX centuries. The use of ombrotrophic peatlands that are specific isolated ecosystems fed only through atmospheric deposition may serve as its natural archives. Accumulation of Cd and Pb from atmospheric deposition in undisturbed soil layers in relation to their total deposited cumulative loads recorded in the ombrotrophic peat bog was exemplified in the Izera Mountains, an area historically heavily affected with the transboundary long-range transmission of pollutants from Germany, the Czech Republic, and Poland. Balance of deposited Cd and Pb loads in soil in relation to the total cumulative deposition determined from peat records showed 30% depletion of Cd load in the soil profile due to washout of mobile phases, while that of Pb practically did not decline. The deposited element accumulation and release/depletion in undisturbed soil profiles can thus be quantified in relation to the total cumulative load of atmospheric deposition. This shows a new prospective application of peat bog records as monitors of total cumulative loads of trace elements supplied to soils from atmospheric deposition.

Rapid virucidal activity of an air sanitizer against aerosolized MS2 and Phi6 phage surrogates for non-enveloped and enveloped vertebrate viruses, including SARS-CoV-2.

An air sanitizer was evaluated using an aerobiology protocol, compliant with the U.S. Environmental Protection Agency's Air Sanitizer Guidelines, for virucidal activity against bacteriophages Phi6 and MS2 (used as surrogates for enveloped and non-enveloped human pathogenic viruses). The phages were suspended in a medium containing a tripartite soil load simulating body fluids and aerosolized using a six-jet Collison nebulizer in an enclosed 25 m3 aerobiology chamber at 22 ± 2°C and 50 ± 10% relative humidity. The air sanitizer was sprayed into the chamber for 30 s. Viable phages in the air were captured directly, in real time, on host bacterial lawns using a slit-to-agar sampler. Reductions in viable phage concentration ≥3.0 log10 (99.9%) were observed after a mean exposure of 3.6 min for Phi6, suggesting efficacy against enveloped viruses (e.g., SARS-CoV-2, influenza, and RSV), and ~10.6 min for MS2, suggesting virucidal efficacy for non-enveloped viruses (e.g., noroviruses and rhinoviruses). This targeted air sanitization approach represents an important non-pharmaceutical public health intervention with virucidal efficacy against airborne viral pathogens.IMPORTANCEAirborne viruses are implicated in the transmission indoors of respiratory and enteric viral infections. Air sanitizers represent a non-pharmaceutical intervention to mitigate the risk of such viral transmission. We have developed a method that is now an ASTM International standard (ASTM E3273-21) as well as a test protocol approved by the U.S. EPA to evaluate the efficacy of air sanitizing sprays for inactivating airborne MS2 and Phi6 bacteriophage (used as surrogates for non-enveloped and enveloped human pathogenic viruses, respectively). The test phages were individually suspended in a soil load and aerosolized into a room-sized aerobiology chamber maintained at ambient temperature and relative humidity. Reductions in viable phage concentration ≥3.0 log10 (99.9%) were observed after a mean exposure of 3.6 min for Phi6, suggesting efficacy against enveloped viruses (e.g., SARS-CoV-2; influenza; RSV), and ~10.6 min for MS2, suggesting virucidal efficacy for non-enveloped viruses (e.g., noroviruses and rhinoviruses). The data suggest the utility of the air sanitizer for mitigating the risk of indoor viral transmission during viral pandemics and outbreaks.

An Experimental Study on Industrial Concete Pile Foundation in Soft Soil: Comparison of Monolithic and Pile with Welded Joints

This study presents an experimental investigation into the industrial foundation piles. The research carried out employed both destructive and non-destructive testing methods to evaluate the concrete compressive strength and flexural strength capacity of the piles under monotonic loading. The Destructive Test (DT) involves a 28-day cylinder concrete compressive test, while the Non-Destructive Test (NDT) utilizes the Ultrasonic Pulse Velocity (UPV) and Rebound Hammer (RH) tests. The flexural strength test is conducted using a loading frame, and the results are compared to the GeoPIV-RG, which measures the displacement during the test. The experimental investigations provide insights into the behavior of pile joints when subjected to monotonic load in soft and loose soil. The results indicate a significant difference between the compressive strength obtained from the DT and NDT, with a ratio of 0.64-0.74. Furthermore, the failure occurred at the joints, rather than the welded area, with the ratio of the initial stiffness of the piles with joints to the monolithic pile being 0.15 for zig-zag welded and 0.30 for circular welded, and reaching an average value of 0.225. According to the GeoPIV-RG result, the displacement is similar to the flexural strength test result.

A new pile-soil interface and its application in battered mini piles under monotonic lateral load in cohesive soil

A new pile-soil interface and its application in battered mini piles under monotonic lateral load in cohesive soil

Reduction of microbial load in soil by gas generated using non-thermal atmospheric pressure plasma

Elevation of the microbial load in soil resulting from contamination with organic wastes of biological origin increases the chances of emerging soil-borne pathogens and disturbance of nutrient cycling. We analyzed the potential of gas generated using atmospheric-pressure non-thermal plasma as a tool for reducing the microbial load in soil and its impact on the soil microbial community and fertility. The gas generated by a cylinder-type single pair of dielectric barrier discharge (DBD) electrode plasma inactivated over 90% of bacterial cells and fungal spores after 5 and 20min of treatment, respectively, in both suspension and vermiculite. Gas generated using four pairs of DBD electrode plasma eradicated approximately 50% of bacterial cells and 40% of fungal spores in nursery soil. It also eliminated approximately 10-29% of aerobic natural microbiota in field soil after 60min of treatment. The diversity of microbial species in the plasma gas-treated field soil was slightly lower than that in the untreated soil, and the relative abundances of the phyla Proteobacteria and Basidiomycota were reduced in the plasma gas-treated soil. Spinach plant growth and nitrate levels increased significantly in the plasma gas-treated field soil. Our data suggest that plasma-generated gases can be used for soil sanitation with no drastic changes to the soil microbial community and soil fertility enhancement.

Full-scale testing and monitoring of geosynthetics-stabilized flexible pavement in Alberta, Canada

Full-scale testing and monitoring of geosynthetics-stabilized flexible pavement in Alberta, Canada

Formulation and Implicit Numerical Integration of a Kinematic Hardening Model for Unsaturated Soils

ABSTRACTCurrently, our understanding of material‐scale deterioration resulting from meteorologically induced variations in pore water pressure and its significant impact on infrastructure slopes is limited. To bridge this knowledge gap, we have developed an extended kinematic hardening constitutive model for unsaturated soils that refines our understanding of weather‐driven deterioration mechanisms in heterogeneous clay soils. This model has the capability of predicting the irrecoverable degradation of strength and stiffness that has been shown to occur when soils undergo wetting and drying cycles. The model is equipped with a fully coupled and hysteretic water retention curve and a hysteretic loading–collapse curve and has the capability to predict the irrecoverable degradation of strength and stiffness that occurs during cyclic loading of soils. Here, we employ a fully implicit stress integration technique and give particular emphasis to deriving a consistent tangent operator, which includes the linearisation of the retention curve. The proposed algorithm is evaluated for efficiency and performance by simulating various stress and strain‐driven triaxial paths, and the accuracy of the integration technique is evaluated through the use of convergence curves.

Lateral Response Analysis of a Large‐Diameter Pile Under Combined Horizontal Dynamic and Axial Static Loads in Nonhomogeneous Soil

ABSTRACTThe large diameter piles are widely used in structures such as offshore wind turbines due to their superior lateral load‐bearing capacity. To explore the lateral response of a large‐diameter pile under combined horizontal dynamic and axial static loads in nonhomogeneous soil, a simplified analytical model of the pile–soil interaction is developed. This model represents the pile as a Timoshenko beam resting on the Pasternak foundation, incorporating the double‐shear effect by considering both pile and soil shear. The governing matrix equations for the pile elements are derived from the principle of virtual work. Further, the pile's lateral deformations and internal forces are obtained using the modified finite beam element method (FBEM) and then validated through existing analytical solutions. Finally, the contribution of various properties of pile, soil, and applied load to the pile's lateral vibration response are performed. It is found that both pile and soil shear effects significantly impact the lateral dynamic response of a large‐diameter pile. Additionally, in nonhomogeneous soil, decreasing surface soil strength and dimensionless frequency lead to increased lateral displacements and bending moments of the pile, which are significantly affected by the P‐Δ effect under increasing axial load.

Nickel toxicology testing in alternative specimen from farm ruminants in a urban polluted environment

Nickel toxicology testing in alternative specimen from farm ruminants in a urban polluted environment

White rot fungi to decompose organophosphorus insecticides and their relation to soil microbial load and ligninolytic enzymes

The functional and structural features of microbial load in soil are influenced by the presence of insecticides. This study examined the impact of two organophosphorus insecticides, dimethoate and parathion on the microbial load of soil. The colony count of fungi, actinomycetes, bacteria, and nitrogen fixing bacteria was reduced after insecticides application at 7 and 14 days, but at 28 days the colony count began to increase. The growth of two white rot fungi including Pleurotus sajor-caju and Phanerochaete chrysosporium was affected by parathion, which was reflected by a decrease in colony radius to 1.85±0.05 and 0.75±0.06 cm, respectively, and by dimethoate, reflected by a decrease in colony radius to 3.33±0.12 and 1.85±0.05 cm, respectively at 40 mg/L compared to colony radius at control 7.90±0.12 and 7.50±0.06 cm, respectively. The applied low concentration (10 mg/L) encouraged P. sajor-caju and P. chrysosporium to remove up to 87.7% and 81.8% of dimethoate, respectively, and 69.20 and 68.30% of parathion, respectively compared with the decomposition at high dose (40 mg/L) at 28 days. The presence of insecticides induced the production of ligninolytic enzymes lignin peroxidase, laccase, and manganase peroxidase.

The Method of the Natural Frequency of the Offshore Wind Turbine System Considering Pile–Soil Interaction

Accurately and efficiently evaluating the influence of pile–soil interaction on the overall natural frequency of wind turbines is one of the difficulties in current offshore wind power design. To improve the structural safety and reliability of the offshore wind turbine (OWT) systems, a new closed-form solution method of the overall natural frequency of OWTs considering pile–soil interactions with highly effective calculations is established. In this method, Hamilton’s principle and the equivalent coupled spring model (ECS model) were firstly combined. In Hamilton’s theory, the Timoshenko beam assumption and continuum element theory considering the three-dimensional displacement field of soil were used to simulate the large-diameter monopile–soil interaction under lateral load in multilayer soil. Case studies were used to validate the proposed method’s correctness and efficiency. The results show that when compared with the data of 13 offshore wind projects reported in existing research papers, the difference between the overall natural frequency calculated by the proposed method and that reported in this study is within ±10%. This calculation method achieves the goal of convenient, fast and accurate prediction of the overall natural frequency of offshore wind systems.

Application of SWAT to assess peatland forestry impacts on water quality

ABSTRACT Peatland drainage can affect the natural state of hydrological conditions and nutrient loading but is rarely included in catchment-scale models. To understand the gap, we aimed to use the soil and water assessment tool (SWAT) to observe drained peatlands and their properties to predict nutrients and suspended solids (SS) in the peatland-dominated Simojoki catchment. We integrated drainage networks in SWAT to (i) identify drainage parameters; (ii) determine annual loads and mean concentrations of SS, organic phosphorus (Org-P), total phosphorus (TP), organic nitrogen (Org-N), and total nitrogen (TN); (iii) understand spatial variation of nutrients and SS; and (iv) investigate uncertainty ranges for the estimates. The calibrated model showed a 9.6 per cent bias between the simulated flow and the observations with low-to-medium loading variations for the water quality parameters. For Org-N and TN, the highest loading per year was at the downstream outlet, whereas for SS, Org-P, and TP, it was higher at the upstream outlet of the catchment. This approach of representing the drained peatland in SWAT indicated maximum spatial distributed load in the peat soil in the clear-cut area and can be beneficial in future hydrological modelling efforts in identifying the status of nutrients or SS.