The digging mechanism is the component of garlic harvesters that consumes the most energy. Consequently, there are theoretical gaps in the design of resistance reduction. These gaps are due to the complexity of the interaction dynamics between the shovel and the soil, and the insufficient understanding of the evolution patterns of soil damage. To address these challenges, this study develops a finite element model of the shovel-soil system using damage mechanics to characterize nonlinear interaction mechanisms under operational loading conditions. The methodology integrates three critical phases: (1) soil damage evolution analysis was employed to identify key damage parameters for model calibration; (2) systematic finite element simulations were used to evaluate the effects of system variables-entry angle, shovel blade bevel angle, forward speed, and vibration frequency-on forward resistance; (3) orthogonal experimental optimization of these parameters was carried out. Key results include the following: (i) A nonlinear relationship was identified between variables (entry angle, forward speed, and vibration frequency) and resistance reduction. Furthermore, the threshold for optimal performance was determined. The optimal parameters were identified as an entry angle of 20 degrees, a forward speed of 0.39 m/s, and a frequency of 2.6 Hz. (ii) Validation through soil bin experiments, demonstrating strong agreement between simulated and measured load-displacement responses, confirming the predictive accuracy of the model. The research presented in this paper may offer insights into the principles of low-resistance designs for underground fruit harvesting.

Given the significant damage rate observed during the transportation of current garlic combine harvesters in China, this study aims to design a new garlic combine harvester capable of achieving minimal harvest losses. The designed machine can simultaneously complete operations for garlic digging, clamping transport, seedling-bulb separation, soil cleaning, and fruit collection across two rows. Through the use of theoretical analysis and calculation of garlic harvesting operations, the key parameters of soil-breaking device, clamping transport device, length-limiting cutting device, and soil cleaning conveyor were determined. The BoxBehnken test technique was utilized within Design-Expert software, and orthogonal experiments were conducted with the unit's forward speed, digging depth, and soil-breaking angle as test factors, and the stem cutting rate and bulb damage rate as test indices. The test results showed that when the unit's forward speed, digging depth, and soil-breaking angle were 0.49 m/s, 100 mm, and 20 degrees, respectively, the working parameter combination was the best, and the rate of stem cutting and damage were 95.71% and 3.10%, respectively. The findings from the field experiment and optimization aligned closely. This study can provide reference for the development of mechanized garlic harvesting.

The critical state line (CSL) plays an essential role in the constitutive modelling of granular soils. It serves as a reference line for the measurement of the state parameter. The critical state of crushable soils cannot accurately be determined from experimental data because of the ever-changing soil properties due to particle breakage. In this study, two new parameters eB and eb are introduced, which account for the final position and the evolution of CSL of crushable soils during shearing, respectively. To identify the optimal CSL-related parameters from experimental data, a hybrid genetic algorithm combining artificial immune system (AIS) and real-coded genetic algorithm (RCGA), namely AIS-RCGA is adopted. The fitness is defined to minimize the prediction error of both void ratio (or pore water pressure) and deviatoric stress. We have refined the tuning methods for several hyperparameters of AIS-RCGA and proposed a novel method to assess the similarity of individuals within AIS-RCGA. Results show that the new method is more efficient in finding the global optimal for our problem. With optimized model parameters, the new constitutive model can accurately predict the response of crushable soil, outperforming other constitutive model reported in the literature.

Shear wave velocity (Vs) is an important soil parameter to be known for earthquake-resistant structural design and an important parameter for determining the dynamic properties of soils such as modulus of elasticity and shear modulus. Different Vs measurement methods are available. However, these methods, which are costly and labor intensive, have led to the search for new methods for determining the Vs. This study aims to predict shear wave velocity (Vs (m/s)) using depth (m), cone resistance (qc) (MPa), sleeve friction (fs) (kPa), pore water pressure (u2) (kPa), N, and unit weight (kN/m3). Since shear wave velocity varies with depth, regression studies were performed at depths up to 30 m in this study. The dataset used in this study is an open-source dataset, and the soil data are from the Taipei Basin. This dataset was extracted, and a 494-line dataset was created. In this study, using HyperNetExplorer 2024V1, Vs prediction based on depth (m), cone resistance (qc) (MPa), shell friction (fs), pore water pressure (u2) (kPa), N, and unit weight (kN/m3) values could be performed with satisfactory results (R2 = 0.78, MSE = 596.43). Satisfactory results were obtained in this study, in which Explainable Artificial Intelligence (XAI) models were also used.

When analyzing the engineering characteristics of pile-supported embankments in deep soft soil regions, the creep behavior of soft soils cannot be overlooked. In previous numerical analyses, empirical formulas were often used to determine related parameters, which limited the accuracy of the calculations. This study validated the reliability of the soft soil creep (SSC) model using measurement data and proposed an optimized process for SSC parameter selection, aiming to improve both accuracy and practical applicability. A numerical model was established based on actual engineering to study the effects of different pile lengths and spacing on settlement, soil arching, and reinforcement material stress. Key findings include as follows: (1) The SSC model outperforms the Mohr-Coulomb and soft soil models in predicting settlement and stress concentrations. (2) An optimized SSC parameter selection process is proposed, providing reference values for typical soft soils in Zhejiang, China. (3) Settlement increases significantly when pile spacing exceeds 2.8 m in this project, suggesting the existence of a threshold effect of pile spacing on settlement. (4) Increasing pile length reduces differential settlement and the tensile force on reinforcement material, with differential settlement decreasing from 0.268 to 0.114 mm and tensile force dropping from 106 to 89 kN/m as pile length increases from 24 to 30 m. This finding shows the importance of balancing pile length and reinforcement material strength, which can reduce project costs while ensuring the stability and quality of the embankment. This study provides a theoretical basis for the design of pile-supported reinforced embankments in soft soil regions.

Carbon fiber reinforced polymer (CFRP) cable anchors, possessing exceptional mechanical properties and corrosion resistance, are increasingly serving as alternatives to traditional steel strands in coastal excavation support engineering. This study draws upon in -situ tests of deep excavation near the sea to examine the stress characteristics of CFRP cable anchors throughout their service period at various positions within the excavation plane. Moreover, the parameters of these cable anchors are optimized and analyzed through numerical simulations. The study revealed that the planar position, backfilling of the excavation and the time effect significantly affected the service performance of the CFRP cable anchors. As the days increase, the overall axial force and shear stress in the CFRP cable anchors undergo five stages of changes. Compared to steel strands, CFRP cable anchors demonstrated superior supporting effects on the adjacent soil. Given similar engineering geological conditions, the advisable range for inclination angle for CFRP cable anchors ranges between 20(degrees) and 30(degrees), and cable anchor lengths is 10% shorter than the test length up to the test length itself. Within the scope of this study, the optimal support strategy recommends a 30 inclination angle and a length that is 10% shorter than that of the test length.

The extended duration of mulching in Xinjiang cotton fields leads to a significant decline in the tensile strength of plastic film. When recycling is in operation, the soil and the spring teeth of the machinery used can easily cause secondary damage and fracture the residual film. Establishing appropriate working parameters for recycling is essential to enhance the overall quality of collection efforts. By analyzing the motion process of a chain-tooth residual film pickup device, we identified key working parameters that significantly impact the efficiency of recycling. Employing the finite element method (FEM) and a coupled algorithm incorporating smooth particle hydrodynamics (SPH), we developed a coupled finite element model representing the interaction among spring teeth, soil, and residual film. Through simulation and analysis of the process of inserting the spring teeth into the soil to collect film, we derived the governing rules for residual film stress and deformation changes. Utilizing forward speed, rotational angular velocity, and angle of entry into the soil of the spring teeth as test factors and selecting the residual film stress and the residual film deformation as test indices, we conducted a multi-factor simulation test. We established a mathematical model correlating test factors with test indices, and the influence of each factor on the test index was analyzed. Subsequently, we optimized the working parameters of the spring teeth. The results indicated that the optimal working parameters are forward speed of 1111.11 mm/s, rotational angular velocity of 25 rad/s, and angle of entry into the soil of 30 degrees. At these values, the average peak stress of residual film was 4.51 MPa and the height of residual film pickup was 84.48 mm. To validate the optimized the spring teeth impact on performance, field experiments were conducted with recovery rate and winding rate as test indices. The results demonstrated a 92.1% recovery rate and a 1.1% winding rate under the optimal combination of working parameters. The finite element model presented in this paper serves as a reference for designing and analyzing key components of residual film recycling machines.

Tunnels with super-large cross-sections mainly face problems such as large tunnel spans, complex geological conditions, poor self-stability of the surrounding rocks, and poor stability of tunnel structures. If inappropriate support or construction is selected, large deformation, instability, and/or construction damage may occur. Therefore, by considering the Nanlong composite interchange project as the research engineering background, numerical analysis is carried out via FLAC3D finite difference software. Combined with the site survey data, comparative analyses of the displacement field, stress field, and plastic zone are carried out for different construction methods and support schemes. Based on the results of Flac3D numerical simulation analysis and compared with the reserved core soil method for excavation, the double-side heading method for super-span tunnels with weak surrounding rock has advantages and feasibility. In addition, by comparing the schemes and the results of numerical simulation, it is preliminarily concluded that the high-pretension negative Poisson's ratio long and short anchor cable compensation support is characterized by control effects compared with the traditional passive and strong support. The aforementioned can provide technical support for tunnel excavation under complex geological conditions.