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The tetrapod jacket-supported offshore wind turbine is subjected to marine environmental loads, resulting in monotonic and cyclic lateral-compression-tension interaction behavior of the pile-soil system. Although the excellent applicability that has been demonstrated by three-dimensional numerical simulation for aiding the revelation of the mechanism of jacket foundation-soil interaction, a significant challenge remains in accurately reflecting the nonlinear stress-strain relationship and cyclic behavior of the soil, and others. Finite element numerical models are therefore established for laterally loaded tetrapod jacket pile foundations in this study, and a bounding surface model is adopted to simulate the elastoplastic characteristics and cyclic ratchet effect of the soil. Subsequently, a parametric analysis is conducted on different net spacings and aspect ratios of the jacket base-piles to investigate the pile deformation characteristics, bearing mechanisms, evolution of pile-soil interaction, and the internal force development under monotonic and cyclic conditions, respectively. The results indicate that under monotonic loading, the pile deformation pattern transitions from a flexible pile mode to a rigid rotational deformation mode as the aspect ratio decreases. Under cyclic loading, attention should be paid to the asynchronous accumulation of axial forces within the base-piles and its impact on overall bearing performance.

期刊论文 2025-07-01 DOI: 10.1016/j.soildyn.2025.109381 ISSN: 0267-7261

Further investigation into the progression of soil arching under the impact of noncentered tunnel is warranted. This study addresses this need by examining trapdoor models with varying vertical and horizontal spacings between the tunnel and the trapdoor through the discrete element method. The numerical model underwent calibration utilizing data from previous experiments. The results indicated that the soil arching ratio under the impact of noncentered tunnel exhibits four distinct stages: initial soil arching, maximum soil arching, load recovery, and ultimate stage, aligning with observations unaffected by tunnel presence. The minimal disparity in stress ratio within the stationary region was observed when the vertical spacing between the tunnel and the trapdoor ranges between 150 and 200 mm. Moreover, the disturbed area on the left part of the trapdoor extended significantly beyond the trapdoor width, with notably higher disturbance height compared to the right side. When the tunnel deviated from the centerline of the trapdoor, the stress enhancement on the right side was considerably greater compared to the left. Additionally, the displacement of the trapdoor resulted in a reduction of contact force anisotropy in the soil on the side more distant from the tunnel, while increasing it on the side closer to the tunnel.

期刊论文 2025-05-01 DOI: 10.1002/nag.3962 ISSN: 0363-9061

Corn earworm, Helicoverpa zea Boddie (Lepidoptera: Noctuidae), is a common herbivore that causes economic damage to agronomic and specialty crops across North America. The interannual abundance of H. zea is closely linked to climactic variables that influence overwintering survival, as well as within-season host plant availability that drives generational population increases. Although the abiotic and biotic drivers of H. zea populations have been well documented, prior temporal H. zea modeling studies have largely focused on mechanistic/simulation approaches, long term distribution characterization, or degree day-based phenology within the growing season. While these modeling approaches provide insight into H. zea population ecology, growers remain interested in approaches that forecast the interannual magnitude of moth flights which is a key knowledge gap limiting early warning before crops are planted. Our study used trap data from 48 site-by-year combinations distributed across North Carolina between 2008 and 2021 to forecast H. zea abundance in advance of the growing season. To do this, meteorological data from weather stations were combined with crop and soil data to create predictor variables for a random forest H. zea forecasting model. Overall model performance was strong (R2 = 0.92, RMSE = 350) and demonstrates a first step toward development of contemporary model-based forecasting tools that enable proactive approaches in support of integrated pest management plans. Similar methods could be applied at a larger spatial extent by leveraging national gridded climate and crop data paired with trap counts to expand forecasting models throughout the H. zea overwintering range.

期刊论文 2025-04-01 DOI: 10.1093/ee/nvaf011 ISSN: 0046-225X

Ferromanganese nodules (FMNs), simultaneously termed as manganese nodules, are metallic concretions typically found in the B horizon of iron and manganese-rich soils. These nodules are primarily formed through the biomineralization process driven by favorable redox reactions and microbial activity. The formation of FMNs in the soil is governed by complex geochemical interactions and influenced by both biotic and abiotic factors, such as temperature, pH, organic matter, redox potential (Eh), wet/dry cycles, and nucleation sites. FMNs typically vary in size, ranging from a few microns to several centimeters, and exhibit diverse shapes, from spherical to irregular. These nodules play a crucial role in nutrient cycling and the adsorption of heavy metals, including phosphorus, lead, copper, zinc, cobalt, and nickel, thereby improving soil quality and preventing metal leaching into aquatic environments. The ion exchange during redox reactions, complexation, occlusion, and adsorption are the key mechanisms through which heavy metals can become immobilized in soil FMNs. The formation of FMNs involves Mn-oxidizing bacteria, such as Bacillus, Pedomicrobium, Erythrobacter, Pseudomonas putida, Geobacter, and Leptothrix discophora, which use specific functional genes such as mnxG, moxA, mopA, CumA, ombB, omaB, OmcB, and mofA to facilitate manganese oxidation. This process reacts with geological material, resulting in the precipitation of metal leachates and the development of metal oxide coatings that serve as nucleation sites for FMNs. Such microbial activities are not only essential for FMNs formation but also for trapping heavy metals in soil, highlighting their importance in soil biogeochemical cycling and ecological functions. However, further research is needed to unravel the complex biogeochemical interactions that influence FMNs growth and composition, as well as to understand the stabilization and release dynamics of nutrients and heavy metals, and the roles of microbial communities and functional genes involved in these processes, particularly in relation to soil fertility and plant nutrition.

期刊论文 2025-02-01 DOI: 10.1016/j.earscirev.2024.105029 ISSN: 0012-8252

Precisely evaluating the soil pressure above parallel tunnels is of paramount importance. In this study, the deformation characteristics of soil above dual trapdoors were analyzed firstly. A novel multi-arch model for calculating the distribution of the vertical earth pressure on deep-buried parallel tunnel was then proposed based on the limit equilibrium method. The height of the dual arch zone caused by the displacement of the dual trapdoors was calculated with consideration of internal friction angle of the soil, width of the trapdoors, spacing between the dual trapdoors, and elastic modulus of the soil. By comparing with numerical simulation results and existing theoretical calculation models that do not account for the interaction of soil arching effect, it is evident that the proposed model in this study adeptly predicts the vertical stress above the trapdoor. Additionally, it captures the characteristic of upwardly convex stress distribution above the trapdoor. The analysis of parameters conducted on the theoretical calculation model showed that the depth of the trapdoor and the internal friction angle of the soil have a substantial impact, whereas the expansion coefficient exerts a negligible effect on the soil arching ratio above the trapdoor.

期刊论文 2025-02-01 DOI: 10.1007/s11440-024-02420-x ISSN: 1861-1125

Understanding the effects of landscape greening pest control modes (LGPCMs) on carbon storage and soil physicochemical properties is crucial for promoting the sustainable development of urban landscape greening. Climate change and green development have led to increased landscape pest occurrences. However, the impacts of different LGPCMs on carbon storage and soil properties remain unclear. We examined six typical LGPCMs employed in Beijing, China: chemical control (HXFZ), enclosure (WH), light trapping (DGYS), biological agent application (SWYJ), natural enemy release (SFTD), and trap hanging (XGYBQ). Field surveys and laboratory experiments were conducted to analyze their effects on carbon storage and soil physicochemical properties, and their interrelationships. The main results were as follows: (1) Different LGPCMs significantly affected carbon storage in the tree and soil layers (p 0.05). Carbon storage composition across all modes followed the following order: tree layer (64.19%-93.52%) > soil layer > shrub layer > herb layer. HXFZ exhibited the highest tree layer carbon storage (95.82 t/hm(2)) but the lowest soil layer carbon storage (6.48 t/hm(2)), while DGYS performed best in the soil, herb, and shrub layers. (2) LGPCMs significantly influenced soil bulk density (SBD), clay (SC), silt particle (SSP), sand (SS), pH, organic carbon (OC), total nitrogen (TN), and heavy metal content (lead (Pb), cadmium (Cd), mercury (Hg)). WH had the highest TN (1.37 g/kg), TP (0.84 g/kg), SC (10.71%) and SSP (42.14%); HXFZ had the highest Cd (8.98 mg/kg), but lowest OC and Pb. DGYS had the highest OC and Hg, and the lowest Cd, SC, and TP. Under different LGPCMs, the heavy metal content in soil ranked as follows: Pb > Cd > Hg. (3) There were significant differences in the relationship between carbon storage and soil physicochemical properties under different LGPCMs. A significant positive correlation was observed between the soil layer carbon storage, TN, and OC, while significant negative correlations were noted between SS and SC as well as SSP. Under SFTD, the tree layer carbon storage showed a negative correlation with Cd, while under DGYS, it correlated negatively with pH and Hg. In summary, While HXFZ increased the short-term tree layer carbon storage, it reduced carbon storage in the other layers and damaged soil structure. Conversely, WH and DGYS better supported carbon sequestration and soil protection, offering more sustainable control strategies. We recommend developing integrated pest management focusing on green control methods, optimizing tree species selection, and enhancing plant and soil conservation management. These research results can provide scientific guidance for collaborative implementation of pest control and carbon sequestration in sustainable landscaping.

期刊论文 2024-12-01 DOI: 10.3390/f15122235

High-severity wildfires create heterogeneous patterns of vegetation across burned landscapes. While these spatial patterns are well-documented, less is known about the short- and long-term effects of large-scale high-severity wildfires on insect community assemblages and dynamics. Ants are bottom-up indicators of ecosystem health and function that are sensitive to disturbance and fill a variety of roles in their ecosystems, including altering soil chemistry, dispersing seeds, and serving as a key food resource for many species, including the federally endangered Jemez Mountain salamander (Plethodon neomexicanus). We examined the post-fire effects of the 2011 Las Conchas Wildfire on ant communities in the Valles Caldera National Preserve (Sandoval County, New Mexico, USA). We collected ants via pitfall traps in replicated burned and unburned sites across three habitats: ponderosa pine forests, mixed-conifer forests, and montane grassland. We analyzed trends in species richness, abundance, recruitment, loss, turnover, and composition over five sequential years of post-fire succession (2011-2015). Ant foraging assemblage was influenced by burn presence, season of sampling, and macrohabitat. We also found strong seasonal trends and decreases over time since fire in ant species richness and ant abundance. However, habitat and seasonal effects may be a stronger predictor of ant species richness than the presence of fire or post-fire successional patterns.

期刊论文 2024-12-01 DOI: 10.3390/conservation4040049

Grain legumes, such as faba bean (Vicia faba L.), are crucial for protein supply and soil fertility enhancement through nitrogen fixation. However, faba bean cultivation is challenged by Lygus plant bugs (Hemiptera: Miridae), which cause significant crop damage and seed quality loss. This study aimed to evaluate Lygus preferences between faba bean and alternative crops to develop effective management strategies. We conducted choice bioassay experiments under laboratory conditions and field plot experiments. Laboratory results indicated sex-based host preferences, with males favoring faba beans and females preferring canola. Field studies showed that faba beans adjacent to canola had higher Lygus abundance and damage compared to those next to peas, flax, and safflower. Safflower and sunflower demonstrated potential as trap crops to reduce Lygus damage to faba beans. Our findings provide insights into Lygus behavior and suggest that a combination of trap cropping, and targeted insecticide use could mitigate the impact of Lygus infestations on faba bean cultivation.

期刊论文 2024-12-01 DOI: 10.1007/s11829-024-10095-0 ISSN: 1872-8855

Polymeric materials have been shown to be rate-dependent materials, that is, their response will vary depending on the conditions to which they are subjected. The present work details the formulation, validation and implementation of a viscoplastic constitutive model with stress, strain, temperature, and relative humidity dependencies aimed to simulate the long-term response of polymeric materials, particularly that of polyester. The model is capable of predicting primary and secondary creep, often observed in geosynthetic materials. Both creep mechanisms can be modelled independently if needed. For calibration, a wide data-set of polyester strap reinforcement creep measurements was used. The validation process was done using parameters for load-, product-, and material-specific scenarios. Load- and product-specific scenarios showed suitable agreement between simulated and measured data. The coupled capabilities of the model are shown via variable temperature and relative humidity boundary conditions. Due to lack of data, temperature and relative humidity dependencies represent idealized scenarios. Simulations of stress-relaxation response for constant rate of strain scenarios are also provided. The proposed formulation is aimed at modelling the mechanical response of reinforced soil structures while accounting for the effect of in-air or in-soil conditions to which reinforcement materials can be exposed to throughout the structure's life-cycle.

期刊论文 2024-11-01 DOI: 10.1016/j.compgeo.2024.106695 ISSN: 0266-352X

concrete linings in tunnels constructed by drilling and blasting such as NATM serve as a secondary support structure. However, these linings can face unexpected earth pressures if the primary support deteriorates or if ground conditions becomeunfavorable.It is crucial to determine the loosening earth pressure that allows the lining to maintain its structural integrity and prevent damage caused by this pressure. This study proposes a numerical model for simulating the trapdoor test and developinga method for calculating the loosening earth pressure. The discrete element method (DEM) was employed to describe the soil characteristics around the tunnel. Using this numerical model, a sequence of experimental trapdoor steps was simulated, and the loosening earth pressure was analyzed. Contact parameters were calibrated based on an analysis of a triaxial compression test. The reliability of the developed model was confirmed through a comparison between simulation results and laboratory test findings. The model was used tocalculate the contact force applied to the trapdoor plate and to assess the settlement of soil particles. Furthermore, the model accounted for the soil-arching effect, which effectively redistributes the load to the surrounding areas. The proposed model can be applied to analyze the tunnel's cross-sectional dimensions and design stability under various ground conditions

期刊论文 2024-09-25 DOI: 10.12989/gae.2024.38.6.571 ISSN: 2005-307X
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