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The excavation of complex deep foundation pit poses significant risks to the safety of adjacent existing structures. To investigate the force and deformation characteristics of deep foundation pit, this study focuses on the pile-anchor support system of a deep foundation pit for a third-line ship lock on the Xiangjiang River. Model tests and numerical modeling analyses were conducted to evaluate the influence of pile diameters (1.0 m ≤d≤ 2.0 m) on the force and deformation characteristics of pile-anchor support system in deep foundation pit adjacent to buildings. The results indicate the following: (1) The variation pattern of horizontal displacement at the top of pile in the model test is consistent with that observed in the numerical simulation. The bending moment of the pile body exhibits an “S”-shaped distribution, confirming the reliability of numerical model. (2) The horizontal displacement curve of pile body presents a “bulging belly” shape, with smaller displacements at the top and bottom and larger displacements in the middle. The curvature of displacement decreases as the pile diameter increases. (3) Larger pile diameters result in greater bending moments in the pile body, smaller changes in the positions of positive and negative bending moment extremes, and reduced surface settlement. (4) The uplift at the bottom of foundation pit initially decreases and then increases, forming a “hooked” curve. The influence of pile diameter on bottom uplift is relatively minor. (5) Larger pile diameters promote a transition in the active failure mode from semi-infinite soil to finite soil, with d= 1.5 m serving as the critical value for finite soil conditions. (6) Based on economic considerations, d= 1.5 m is determined to be the optimal pile diameter. (7) The active deformation sliding surface of finite soil behind piles is a curve or polyline that is higher than the heel of wall and returns to the adjacent buildings. This study provides valuable experimental data for investigating finite soil deformation behind piles in the pile-anchor support system for deep foundation pit, offering both theoretical significance and practical engineering value.

Under the premise of ensuring modal and strength characteristics, achieving lightweight design of the structure simultaneously has become a key issue of concern for major automobile manufacturers and research institutions. To reduce the mass redundancy of the bus chassis frame, save production costs and energy consumption, a multi-objective optimization scheme based on surrogate model technology was proposed, which could maximize weight reduction without reducing the natural frequency or increasing the peak stress. According to the working principle, load characteristics and composition of the chassis frame, a parametric coupling model for modal and strength was constructed, and the stress, deformation, natural frequency and vibration mode characteristics of the overall structure were obtained. The dimensions of H-steel were determined as design variables, and the discrete mapping data sets of maximum stress, first-order natural frequency and mass were obtained through the Latin square design scheme. Parameters such as the coefficient of determination, adjusted coefficient of determination and root mean square error were selected as the standard evaluation indicators for the accuracy of the response surface model. The reliability of different surrogate models was compared and analyzed, and finally the Kriging model was adopted as the approximation function in the construction of the mathematical model. An optimized mathematical model was constructed to convert the modal and strength objectives into boundary conditions. The design variables meeting the optimization objectives were derived through the sequential quadratic programming algorithm. The results showed that, without reducing the requirements for strength and stiffness indicators, this optimization scheme could reduce the weight of the chassis frame by 9.94 %, which has good economic benefits and engineering value.

Permafrost in the Qinghai-Tibet Plateau is highly susceptible due to thawing and degradation under the climate warming and extreme warming events, which can trigger surface subsidence and uplift phenomena. This study investigates the vertical surface deformation along the Qinghai-Tibet Engineering Corridor (QTEC) based on the dataset derived from interferometric synthetic aperture radar (InSAR) processing of the ascending and descending Sentinel-1 datasets. Using the geographical detector method, 24 potential factors influencing deformation was selected, including climatic, topographic, soil, hydrological, vegetation index, and cryospheric indicators to explore the driving mechanisms according to the q-value of factor detection processing. Results indicate that climatic factors (mean annual temperature and precipitation) and permafrost-related parameters (surface frost number, freezing index, thawing index) are the primary drivers of vertical deformation, with the q-value greater than 0.095. Topographic parameters (latitude, elevation, topographic relief, slope, longitude) also significantly influence deformation with the q-value between 0.054 and 0.086, followed by the east-west deformation rate and soil organic matter content with the q-value at 0.052, while other factors with the q-value less than 0.05. This study elucidates the intrinsic mechanisms driving surface subsidence and uplift along the QTEC, providing a theoretical foundation for the construction of future infrastructure projects and the maintenance of existing engineering facilities in permafrost regions.

To systematically investigate the protective effects of helmets against human head injuries under various shock wave conditions, a finite element head-helmet coupling model was developed. This model analyzed how helmets influence biomechanical response parameters, such as intracranial and cranial pressure, when subjected to a single blast wave and its accompanying shock wave. While extensive research exists on single blast scenarios, studies on the more complex and militarily relevant accompanying shock waves, which pose a greater threat due to prolonged loading and multiple reflections, remain scarce. Several impact scenarios were considered, including single frontal impact, positive continuous impacts, successive sidewall impacts, and simultaneous frontal and lateral impacts. The study examined the dynamic changes in brain tissue within a blast environment to assess the efficacy of helmets in protecting the human head. In single frontal impact scenarios, helmets effectively reduced intracranial pressures in the frontal, occipital, and parietal lobes by 32 %, 38 %, and 19 %, respectively, while significantly decreasing the stress peak at the back of the skull. During positive continuous impacts, helmets decreased intracranial pressure in the parietal and occipital lobes by 36 % and 21 %, respectively, although their effectiveness in reducing frontal lobe pressure was limited due to inadequate facial protection. For successive sidewall impacts, helmet protection delayed the blast wave, reducing intracranial pressure in the frontal lobe by 60 kPa but increasing pressure in the parietal lobe by 80 kPa. This alleviated stress on the skull’s rear while increasing stress on the opposite side. In scenarios involving simultaneous frontal and lateral impacts, lateral blasts increased parietal intracranial pressure by 20 kPa, with the right hemisphere experiencing more pressure than the left due to the mitigating effect of reflective side blasts on skull stress. The study found that, compared to single blast waves, accompanying shock waves present a greater risk of cranial injuries due to their prolonged impact. These findings address a critical gap in blast neurotrauma research and provide valuable insights into the biomechanics of head injuries under realistic multi-blast conditions, which can directly inform the design of improved helmets with enhanced protection in complex blast environments. However, because shock waves may originate from multiple directions and elevations, the protective capability of conventional helmets for the facial region remains limited.

In order to promote the resource utilization of the byproducts of municipal solid waste incineration in asphalt pavement materials, this study selected different types of waste incineration fly ash as fillers and prepared waste fly ash-asphalt mastic materials. The Brookfield viscosity test was used to investigate the variation in apparent viscosity of the waste fly ash-asphalt mastic at different temperatures. The dynamic shear rheological test was employed to study the effects of fly ash content on the viscoelastic properties of asphalt under different frequencies. The low-temperature bending beam rheological test was used to analyze the changes in creep stiffness and creep rate of the waste fly ash-asphalt mastic. Based on this, the rotating film oven aging test was conducted to investigate the mass loss and softening point increment of the waste fly ash-asphalt mastic. The results indicated that the small particle size and developed pore structure of fly ash contributed to the adsorption of asphalt components, enhancing the volume of the mastic. As the fly ash content increased, its specific surface area also increased, further promoting the increase in the viscosity of the asphalt mastic. Under low-temperature conditions, the asphalt mastic became more prone to hardening and brittleness, which resulted in poorer low-temperature cracking resistance, consistent with the ductility results.

This paper presents a co-simulation of MATLAB and CarSim to control and model a vehicle suspension system under different road surface conditions, either wet or dry, using an active fuzzy controller in MATLAB. CarSim is a professional vehicle simulation software capable of modeling nonlinear car dynamics with various uncertainties. These uncertainties are addressed by the fuzzy set approach due to its qualitative and robust control capabilities, effectively handling noise, disturbances (such as road conditions), and unknown parameters in CarSim’s vehicle model. The design of an active steering controller and rotational torque system using a fuzzy controller is crucial for enhancing road safety, especially given the increasing number of vehicle crashes. The research methodology varies based on the study's purpose, nature, and implementation capabilities. Accordingly, this research focuses on designing an integrated controller for an active four-wheel-drive system and direct rotary torque control using a fuzzy control method in the MATLAB Simulink environment. This study is analytical and functional, utilizing CarSim for simulation. A fuzzy logic-based integrated control system was designed for steady-state control to improve vehicle stability and steering. The controller adjusts the steering angle and torque to regulate the vehicle’s angular velocity and slip angle under various conditions. As tire performance changes during different maneuvers, the controller dynamically adapts its output to maintain optimal operation within the effective performance range. The significance of using fuzzy logic lies in its ability to handle non-linearity without requiring approximation, ensuring high accuracy. Additionally, it delivers excellent results in enhancing vehicle stability. The findings indicate that the controller significantly improves the vehicle’s dynamic behavior across different driving maneuvers compared to an uncontrolled vehicle.

This paper not only explores the fundamental aspects of but also brings new ideas for maintenance, repair, and overhaul (MRO) operations of robotic systems (RS). This synthesis is based on the limited scholarly research in this area and on information gathered from comprehensive web searches and analysis of corporate websites so that the results reflect the current views of RS developers and operators. The paper describes several crucial areas concerning RS MRO: maintenance of robotic systems, challenges and best practices for RS MRO, predictive maintenance variables and key performance indicators, data analytics, software solutions for RS MRO, and logistics/supply chain approach that should be considered. These insights provide not only a comprehensive understanding of the current state of RS MRO but also describe trends and suggestions for the future of RS MRO, emphasizing the novelty of the proposed research conducted. Key trends that organizations will need to address include the use of artificial intelligence (AI) models and the increasing importance of RS MRO logistics and supply chain management.

With China’s rapid infrastructure development, rotating beam bridge technology is widely used for constructing bridges over existing lines and complex terrains. As spans and structural complexity increase, wind-induced instability during rotation – especially for large-span rigid frame bridges – has become a critical concern. This study investigates the wind resistance stability of a rigid frame bridge before and during rotation. Using a static gust wind load model, bending moments, friction moments, and stability coefficients under cross-bridge and longitudinal winds are analyzed, considering dynamic friction and unbalanced weights. Results show that: (1) higher dynamic friction significantly improves stability before rotation, as friction from the spherical hinge resists wind-induced overturning; (2) during rotation, lateral wind dominates cross-bridge stability, while longitudinal stability depends on both wind and unbalanced loads; (3) counterweight adjustment and high-friction coatings effectively enhance anti-overturning capacity. The findings confirm construction safety and provide valuable references for wind-resistant design in similar rotating bridge projects.